text:
A. L. N. Reddy
Texas A&M University
M. Allman
E. Blanton
Purdue University
August 2006
Improving the Robustness of TCP to Non-Congestion Events
Status of This Memo
This memo defines an Experimental Protocol for the Internet community. It does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.
Copyright Notice
Copyright © The Internet Society (2006).
This document specifies Non-Congestion Robustness (NCR) for TCP. In the absence of explicit congestion notification from the network, TCP uses loss as an indication of congestion. One of the ways TCP detects loss is using the arrival of three duplicate acknowledgments. However, this heuristic is not always correct, notably in the case when network paths reorder segments (for whatever reason), resulting in degraded performance. TCP-NCR is designed to mitigate this degraded performance by increasing the number of duplicate acknowledgments required to trigger loss recovery, based on the current state of the connection, in an effort to better disambiguate true segment loss from segment reordering. This document specifies the changes to TCP, as well as the costs and benefits of these modifications.
Table of Contents
1. Introduction ....................................................2 1.1. Terminology ................................................4 2. NCR Description .................................................5 3. Algorithm .......................................................6 3.1. Initialization .............................................8 3.2. Terminating Extended Limited Transmit and Preventing Bursts ..........................................9 3.3. Extended Limited Transmit .................................10 3.4. Entering Loss Recovery ....................................11 4. Advantages .....................................................12 5. Disadvantages ..................................................12 6. Related Work ...................................................13 7. Security Considerations ........................................14 8. Acknowledgments ................................................14 9. IANA Considerations ............................................14 10. References ....................................................14 10.1. Normative References .....................................14 10.2. Informative References ...................................15
1. Introduction
One strength of TCP [RFC793] lies in its ability to adjust its sending rate according to the perceived congestion in the network [Jac88, RFC2581]. In the absence of explicit notification of congestion from the network, TCP uses segment loss as an indication of congestion (i.e., assuming queue overflow). TCP receivers send cumulative acknowledgments (ACKs) indicating the next sequence number expected from the sender for arriving segments [RFC793]. When segments arrive out of order, duplicate ACKs are generated. As specified in [RFC2581], a TCP sender uses the arrival of three duplicate ACKs as an indication of segment loss. The TCP sender retransmits the lost segment and reduces the load imposed on the network, assuming the segment loss was caused by resource contention within the network path. The TCP sender does not assume loss on the first or second duplicate ACK, but waits for three duplicate ACKs to account for minor packet reordering. However, the use of this constant threshold of duplicate ACKs has several problems that can be mitigated with a dynamic threshold.
The following is an example of TCP's behavior:
- TCP A is the data sender, and TCP B is the data receiver.
- TCP A sends 10 segments, each consisting of a single data byte (i.e., transmits bytes 1-10 in segments 1-10).
- Assume segment 3 is dropped in the network.
- TCP B cumulatively acknowledges segments 1 and 2, making the cumulative ACK transmitted to the sender 3 (the next expected sequence number). (Note: TCP B may generate one or two ACKs, depending on whether delayed ACKs [RFC1122, RFC2581] are employed.)
- The arrival of segments 4-10 at TCP B will each trigger the transmission of a cumulative ACK for sequence number 3. (Note: [RFC2581] recommends that delayed ACKs not be used when the ACK is triggered by an out-of-order segment.)
- When TCP A receives the third duplicate ACK (or fourth ACK overall) for sequence number 3, TCP A will retransmit segment 3 and reduce the sending rate by roughly half (see [RFC2581] for specifics on the congestion control state adjustments).
Alternatively, suppose segment 3 was not dropped by the network, but rather delayed such that segment 3 arrives at TCP B after segment 10. The above scenario will play out in precisely the same manner insomuch as a retransmission of segment 3 will be triggered. In other words, TCP is not capable of disambiguating this reordering event from a segment loss, resulting in an unnecessary retransmission and rate reduction.
The following is the specific motivation behind making TCP robust to reordered segments:
- A number of Internet measurement studies have shown that packet reordering is not a rare phenomenon [Pax97, BPS99, JIDKT03, GPL04]. Further, the reordering can be well beyond that required for fast retransmit to be falsely triggered.
* [BA02, ZKFP03] show the negative performance implications that packet reordering has on current TCP.
- The requirement imposed by TCP for almost in-order packet delivery places a constraint on the design of future technology. Novel routing algorithms, network components, link-layer retransmission mechanisms, and applications could all be looked at with a fresh perspective if TCP were to be more robust to segment reordering. For instance, high-speed packet switches could cause resequencing of packets if TCP were more robust. There has been work proposed in the literature explicitly to ensure that packet ordering is maintained in such switches (e.g., [KM02]). Also, link-layer mechanisms that attempt to recover from packet corruption by retransmitting could be allowed to reorder packets, and thus increase the chances of local loss repair rather than rely on TCP to repair the loss (and, needlessly reduce its sending rate). Additional examples include multi-path routing, high-delay satellite links, and some of the schemes proposed for a differentiated services architecture. By making TCP more robust to non-congestion events, TCP-NCR may open the design space of the future Internet components.
In this document, we specify a set of TCP sender modifications to provide Non-Congestion Robustness (NCR) to TCP. In particular, these changes are built on top of TCP with selective acknowledgments (SACKs) [RFC2018] and the SACK-based loss recovery scheme given in [RFC3517], since SACK is widely deployed at this point ([MAF05] indicates that 68% of web servers and 88% of web clients utilize SACK as of spring 2004).
Note that the TCP-NCR algorithm provided in this document could be easily adapted to SCTP [RFC2960] since SCTP uses congestion control algorithms similar to TCP's (and thus has the same reordering robustness issues).
As noted in several places in the remainder of this document, we consider TCP-NCR experimental in that more experience with the techniques is required before TCP-NCR should be used on a large scale on the Internet. We encourage implementation and experimentation with TCP-NCR in the hopes of gaining an understanding of its suitability for wide-scale deployment.
The remainder of this document is organized as follows. Section 2 provides a high-level description of the TCP-NCR mechanisms. In Section 3, we specify the TCP-NCR algorithm. Section 4 provides a brief overview of the benefits of TCP-NCR, while Section 5 discusses the drawbacks. Section 6 discusses related work. Section 7 discusses security concerns.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
Readers should be familiar with the TCP terminology (e.g., FlightSize, Pipe) given in [RFC2581] and [RFC3517].
2. NCR Description
As discussed above, in the face of packet reordering, three duplicate ACKs may not be enough to disambiguate loss from reordering. In this section we provide a non-normative sketch of TCP-NCR. The detailed algorithms for implementing Non-Congestion Robustness for TCP are presented in the next section.
The general idea behind TCP-NCR is to increase the threshold used to trigger a fast retransmission from the current fixed value of three duplicate ACKs [RFC2581] to approximately a congestion window of data having left the network (but not less than the currently standardized value of three duplicate ACKs). Since cwnd represents the amount of data a TCP flow can transmit in one round-trip time (RTT), waiting to receive notice that cwnd bytes have left the network before deciding whether the root cause is loss or reordering imposes a delay of roughly one RTT on both the retransmission and the congestion control response. The appropriate choice for a new value of the threshold is essentially a trade-off between making the best decision regarding the cause of the duplicate ACKs and responsiveness. The choice to trigger a retransmission only after a cwnd's worth of data is known to have left the network represents roughly the largest amount of time a TCP can wait before the (often costly) retransmission timeout may be triggered. Therefore, the algorithm described in this document attempts to make the best decision possible at the expense of timeliness.
Simply increasing the threshold before retransmitting a segment can make TCP brittle to packet loss or ACK loss since such loss reduces the number of duplicate ACKs that will arrive at the sender from the receiver. For instance, if the cwnd is 10 segments and one segment is lost, a duplicate ACK threshold of 10 will never be met because duplicate ACKs corresponding to at most 9 segments will arrive at the sender. To offset the issue of loss, we extend TCP's Limited Transmit [RFC3042] scheme to allow for the sending of new data during the period when the TCP sender is disambiguating loss and reordering. This new data serves to increase the likelihood that enough duplicate ACKs arrive at the sender to trigger loss recovery if it is appropriate.
Note that TCP tightly couples reliability and congestion control: when a segment is declared lost, a retransmission is triggered, and a change to the sending rate is also made on the assumption that the drop is due to resource contention [RFC2581]. Therefore, simply by changing the retransmission trigger, the congestion control response is also changed. However, we lack experience on the Internet as to whether delaying the point that a rate reduction takes place is appropriate for wide-scale deployment. Therefore, the Extended Limited Transmit mechanism proposed in this document offers two variants for experimentation.
The first Extended Limited Transmit variant, Careful Limited Transmit, calls for the transmission of one previously unsent segment, in response to duplicate acknowledgments, for every two segments that are known to have left the network. This effectively halves the sending rate, since normal TCP operation calls for the sending of one segment for every segment that has left the network. Further, the halving starts immediately and is not delayed until a retransmission is triggered. In the case of packet reordering (i.e., not segment loss), the congestion control state is restored to its previous state when reordering is determined.
The second variant, Aggressive Limited Transmit, calls for transmitting one previously unsent data segment, in response to duplicate acknowledgments, for every segment known to have left the network. With this variant, while waiting to disambiguate the loss from a reordering event, ACK-clocked transmission continues at roughly the same rate as before the event started. Retransmission and the sending rate reduction happen per [RFC2581, RFC3517], albeit with the delayed threshold described above. Although this approach delays legitimate rate reductions (possibly slightly and temporarily aggravating overall congestion on the network), the scheme has the advantage of not reducing the transmission rate in the face of segment reordering.
Which of the two Extended Limited Transmit variants is best for use on the Internet is an open question.
3. Algorithm
The TCP-NCR modifications make two fundamental changes to the way [RFC3517] currently operates, as follows.
First, the trigger for retransmitting a segment is changed from three duplicate ACKs [RFC2581, RFC3517] to indications that a congestion window's worth of data has left the network. Second, TCP-NCR decouples initial congestion control decisions from retransmission decisions, in some cases delaying congestion control changes relative to TCP's current behavior as defined in [RFC2581]. The algorithm provides two alternatives for extending Limited Transmit. The two variants of extended Limited Transmit are:
Careful Limited Transmit
This variant calls for reducing the sending rate at approximately the same time [RFC2581] implementations reduce the congestion window, while at the same time withholding a retransmission (and the final congestion determination) for approximately one RTT.
Aggressive Limited Transmit
This variant calls for maintaining the sending rate in the face of duplicate ACKs until TCP concludes that a segment is lost and needs to be retransmitted (which TCP-NCR delays by one RTT when compared with current loss recovery schemes).
A TCP-NCR implementation MUST use either Careful Limited Transmit or Aggressive Limited Transmit.
A constant MUST be set, depending on which variant of extended Limited Transmit is used, as follows:
Careful Limited Transmit LT_F = 2/3 Aggressive Limited Transmit LT_F = 1/2
This constant reflects the fraction of outstanding data (including data sent during Extended Limited Transmit) that must be SACKed before a retransmission is triggered. Since Aggressive Limited Transmit sends a new segment for every segment known to have left the network, a total of roughly cwnd segments will be sent during Aggressive Limited Transmit, and therefore ideally a total of roughly 2*cwnd segments will be outstanding when a retransmission is triggered. The duplicate ACK threshold is then set to LT_F = 1/2 of 2*cwnd (or about 1 RTT worth of data). The factor is different for Careful Limited Transmit because the sender only transmits one new segment for every two segments that are SACKed and therefore will ideally have a total of 1.5*cwnd segments outstanding when the retransmission is to be triggered. Hence, the required threshold is LT_F=2/3 of 1.5*cwnd to delay the retransmission by roughly 1 RTT.
There are situations whereby the sender cannot transmit new data during Extended Limited Transmit (e.g., lack of data from the application, receiver's advertised window limit). These situations can lead to the problems discussed in the last section when a TCP does not employ Extended Limited Transmit and is starved for ACKs. Therefore, TCP-NCR adapts the duplicate ACK threshold on each SACK arrival to be as robust as possible given the actual amount of data that has been transmitted, or roughly LT_F times the number of outstanding segments.
The TCP-NCR modifications specified in this document lend themselves to incremental deployment. Only the TCP implementation on the sender side requires modification (assuming both hosts support SACK). The changes themselves are modest. However, as will be discussed below, availability of additional buffer space at the receiver will help maximize the benefits of using TCP-NCR but is not strictly necessary.
The following algorithms depend on the notions provided by [RFC3517], and we assume the reader is familiar with the terminology given in [RFC3517]. The TCP-NCR algorithm can be adapted to alternate SACK- based loss recovery schemes. [BR04, BSRV04] outline non-SACK-based algorithms; however, we do not specify those algorithms in this document and do not recommend them due to both the complexity and security implications of having only a gross understanding of the number of outstanding segments in the network.
A TCP connection using the Nagle algorithm [RFC896, RFC1122] MAY employ the TCP-NCR algorithm. If a TCP implementation does implement TCP-NCR, the implementation MUST follow the various specifications provided in Sections 3.1 - 3.4. If the Nagle algorithm is not being used, there is no way to accurately calculate the number of outstanding segments in the network (and, therefore, no good way to derive an appropriate duplicate ACK threshold) without adding state to the TCP sender. A TCP connection that does not employ the Nagle algorithm SHOULD NOT use TCP-NCR. We envision that NCR could be adapted to an implementation that carefully tracks the sequence numbers transmitted in each segment. However, we leave this as future work.
3.1. Initialization
When entering a period of loss/reordering detection and Extended Limited Transmit, a TCP-NCR MUST initialize several state variables. A TCP MUST enter Extended Limited Transmit upon receiving the first ACK with a SACK block after the reception of an ACK that (a) did not contain SACK information and (b) did increase the connection's cumulative ACK point. The initializations are:
(I.1) The TCP MUST save the current FlightSize.
FlightSizePrev = FlightSize
(I.2) The TCP MUST set a variable for tracking the number of
segments for which an ACK does not trigger a transmission during Careful Limited Transmit.
Skipped = 0
(Note: Skipped is not used during Aggressive Limited Transmit.)
(I.3) The TCP MUST set DupThresh (from [RFC3517]) based on the current FlightSize. DupThresh = max (LT_F * (FlightSize / SMSS),3)
In addition to the above steps, the incoming ACK MUST be processed with the E series of steps in Section 3.3.
3.2. Terminating Extended Limited Transmit and Preventing Bursts
Extended Limited Transmit MUST be terminated at the start of loss recovery as outlined in Section 3.4.
The arrival of an ACK that advances the cumulative ACK point while in Extended Limited Transmit, but before loss recovery is triggered, signals that a series of duplicate ACKs was caused by reordering and not congestion. Therefore, the receipt of an ACK that extends the cumulative ACK point MUST terminate Extended Limited Transmit. As described below (in (T.4)), an ACK that extends the cumulative ACK point and *also* contains SACK information will also trigger the beginning of a new Extended Limited Transmit phase.
Upon the termination of Extended Limited Transmit, and especially when using the Careful variant, TCP-NCR may be in a situation where the entire cwnd is not being utilized, and therefore TCP-NCR will be prone to transmitting a burst of segments into the network. Therefore, to mitigate this bursting when a TCP-NCR in the Extended Limited Transmit phase receives an ACK that updates the cumulative ACK point (regardless of whether the ACK contains SACK information), the following steps MUST be taken:
(T.1) A TCP MUST reset cwnd to:
cwnd = min (FlightSize + SMSS,FlightSizePrev)
This step ensures that cwnd is not grossly larger than the
amount of data outstanding, a situation that would cause a
line rate burst.
(T.2) A TCP MUST set ssthresh to:
ssthresh = FlightSizePrev
This step provides TCP-NCR with a sense of "history". If step (T.1) reduces cwnd below FlightSizePrev, this step ensures that TCP-NCR will slow start back to the operating point in effect before Extended Limited Transmit.
(T.3) A TCP is now permitted to transmit previously unsent data as
allowed by cwnd, FlightSize, application data availability, and the receiver's advertised window.
(T.4) When an incoming ACK extends the cumulative ACK point and also
contains SACK information, the initializations in steps (I.2) and (I.3) from Section 3.1 MUST be taken (but step (I.1) MUST NOT be executed) to re-start Extended Limited Transmit. In addition, the series of steps in Section 3.3 (the "E" steps) MUST be taken.
3.3. Extended Limited Transmit
On each ACK containing SACK information that arrives after TCP-NCR has entered the Extended Limited Transmit phase (as outlined in Section 3.1) and before Extended Limited Transmit terminates, the sender MUST use the following procedure.
(E.1) The SetPipe () procedure from [RFC3517] MUST be used to set
the "pipe" variable (which represents the number of bytes still considered "in the network"). Note: the current value of DupThresh MUST be used by SetPipe () to produce an accurate assessment of the amount of data still considered in the network.
(E.2) If the comparison in equation (1), below, holds and there are
SMSS bytes of previously unsent data available for transmission, then the sender MUST transmit one segment of SMSS bytes.
(pipe + Skipped) <= (FlightSizePrev - SMSS) (1)
If the comparison in equation (1) does not hold or no new data can be transmitted (due to lack of data from the application or the advertised window limit), skip to step (E.6).
(E.3) Pipe MUST be incremented by SMSS bytes.
(E.4) If using Careful Limited Transmit, Skipped MUST be incremented
by SMSS bytes to ensure that the next SMSS bytes of SACKed data processed does not trigger a Limited Transmit transmission (since the goal of Careful Limited Transmit is to send upon receipt of every second duplicate ACK).
(E.5) A TCP MUST return to step (E.2) to ensure that as many bytes
as are appropriate are transmitted. This provides robustness to ACK loss that can be (largely) compensated for using SACK information.
(E.6) DupThresh MUST be reset via:
DupThresh = max (LT_F * (FlightSize / SMSS),3)
where FlightSize is the total number of bytes that have not been cumulatively acknowledged (which is different from "pipe").
3.4. Entering Loss Recovery
When a segment is deemed lost via the algorithms in [RFC3517], Extended Limited Transmit MUST be terminated, leaving the algorithms in [RFC3517] to govern TCP's behavior. One slight change to [RFC3517] MUST be made, however. In Section 5, step (2) of [RFC3517] MUST be changed to:
(2) ssthresh = cwnd = (FlightSizePrev / 2)
This ensures that the congestion control modifications are made with respect to the amount of data in the network before FlightSize was increased by Extended Limited Transmit.
Note: Once the algorithm in [RFC3517] takes over from Extended Limited Transmit, the DupThresh value MUST be held constant until the loss recovery phase is terminated.
4. Advantages
The major advantages of TCP-NCR are twofold. As discussed in Section 1, TCP-NCR will open up the design space for network applications and components that are currently constrained by TCP's lack of robustness to packet reordering. The second advantage is in terms of an increase in TCP performance.
[BR04] presents ns-2 [NS-2] simulations of a pre-cursor to the TCP- NCR algorithm specified in this document, called TCP-DCR (Delayed Congestion Response). The paper shows that TCP-DCR aids performance in comparison to unmodified TCP in the presence of packet reordering. In addition, the extended version of [BR04] presents results based on emulations involving Linux (kernel 2.4.24). These results show that the performance of TCP-DCR is similar to Linux's native implementation that seeks to "undo" wrong decisions according to duplicate-SACK (DSACK) [RFC2883] feedback (similar to the schemes outlined in [ZKFP03]), when packets are reordered by less than one RTT. The advantage of using TCP-DCR over the DSACK-based scheme is that the DSACK-based scheme tries to estimate the exact amount of reordering in the network using fairly complex algorithms, whereas TCP-DCR achieves similar results with less complicated modifications.
In addition, [BR04,BSRV04] illustrate the ability of TCP-DCR to allow for the improvement of other parts of the system. For example, these papers show that increasing TCP's robustness to packet reordering allows a novel wireless ARQ mechanism to be added at the link-layer. The added robustness of the link-layer to channel errors, in turn, increases TCP performance by not requiring TCP to retransmit packets that were dropped due to corruption (and thus also prevents TCP from needlessly reducing the sending rate when retransmitting these segments).
5. Disadvantages
Although all the changes outlined above are implemented in the sender, the receiver also potentially has a part to play. In particular, TCP-NCR increases the receiver's buffering requirement by up to an extra cwnd -- in the case of the TCP sender using Aggressive Limited Transmit and actual loss occurring in the network. Therefore, to maximize the benefits from TCP-NCR, receivers should advertise a large window to absorb the extra out-of-order traffic. In the case that the additional buffer requirements are not met, the use of the above algorithm takes into account the reduced advertised window -- with a corresponding loss in robustness to packet reordering.
In addition, using TCP-NCR could delay the delivery of data to the application by up to one RTT because the fast retransmission point is delayed by roughly one RTT in TCP-NCR. Applications that are sensitive to such delays should turn off the TCP-NCR option. For instance, a socket option could be introduced to allow applications to control whether NCR would be used for a particular connection.
Finally, the use of TCP-NCR makes the recovery from congestion events sluggish in comparison to the standard reaction in [RFC2581]. [BR04, BSRV04] show (via simulation) that the delay in congestion response has minimal impact on the connection itself and the traffic sharing a bottleneck. [BBFS01] also indicates (again, via simulation) that "slowly responsive" congestion control may be safe for deployment in the Internet. These studies suggest that schemes that slightly delay congestion control decisions may be reasonable; however, further experimentation on the Internet is required to verify these results.
6. Related Work
Over the past few years, several solutions have been proposed to improve the performance of TCP in the face of segment reordering. These schemes generally fall into one of two categories (with some overlap): mechanisms that try to prevent spurious retransmits from happening and mechanisms that try to detect spurious retransmits and "undo" the needless congestion control state changes that have been taken.
[BA02,ZKFP03] attempt to prevent segment reordering from triggering spurious retransmits by using various algorithms to approximate the duplicate ACK threshold required to disambiguate loss and reordering over a given network path at a given time. TCP-NCR similarly tries to prevent spurious retransmits. However, TCP-NCR takes a simplified approach compared to those in [BA02, ZKFP03], in that TCP-NCR simply delays retransmission by an amount based on the current cwnd (in comparison to standard TCP), while the other schemes use relatively complex algorithms in an attempt to derive a more precise value for DupThresh that depends on the current patterns of packet reordering. While TCP-NCR offers simplicity, the other schemes may offer more precision such that applications would not be forced to wait as long for their retransmissions. Future work could be undertaken to achieve robustness without needless delay.
On the other hand, several schemes have been developed to detect and mitigate needless retransmissions after the fact. [RFC3522, RFC3708, BA02, RFC4015, RFC4138] present algorithms to detect spurious retransmits and mitigate the changes these events made to the congestion control state. TCP-NCR could be used in conjunction with these algorithms, with TCP-NCR attempting to prevent spurious retransmits and some other scheme kicking in if the prevention failed. In addition, note that TCP-NCR is concentrated on preventing spurious fast retransmits; some of the above algorithms also attempt to detect and mitigate spurious timeout-based retransmits.
7. Security Considerations
General attacks against the congestion control of TCP are described in [RFC2581]. SACK-based loss recovery for TCP [RFC3517] mitigates some of the duplicate ACK attacks against TCP's congestion control. This document builds upon that work, and the Extended Limited Transmit algorithms specified in this document have been designed to thwart the ACK division problems that are described in [RFC3465].
8. Acknowledgments
Feedback from Lars Eggert, Ted Faber, Wesley Eddy, Gorry Fairhurst, Sally Floyd, Sara Landstrom, Nauzad Sadry, Pasi Sarolahti, Joe Touch, Nitin Vaidya, and the TCPM working group have contributed significantly to this document. Our thanks to all!
9. References
9.1. Normative References
[RFC793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, September 1981. [RFC2018] Mathis, M., Mahdavi, J., Floyd, S., and A. Romanow, "TCP Selective Acknowledgement Options", RFC 2018, October 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2581] Allman, M., Paxson, V., and W. Stevens, "TCP Congestion Control", RFC 2581, April 1999. [RFC3042] Allman, M., Balakrishnan, H., and S. Floyd, "Enhancing TCP's Loss Recovery Using Limited Transmit", RFC 3042, January 2001. [RFC3517] Blanton, E., Allman, M., Fall, K., and L. Wang, "A Conservative Selective Acknowledgment (SACK)-based Loss Recovery Algorithm for TCP", RFC 3517, April 2003.
9.2. Informative References
[BA02] E. Blanton and M. Allman, "On Making TCP More Robust to Packet Reordering," ACM Computer Communication Review, January 2002. [BBFS01] D. Bansal, H. Balakrishnan, S. Floyd and S. Shenker, "Dynamic Behavior of Slowly Responsive Congestion Control Algorithms", Proceedings of ACM SIGCOMM, Sep. 2001. [BPS99] J. Bennett, C. Partridge, and N. Shectman, "Packet reordering is not pathological network behavior," IEEE/ACM Transactions on Networking, December 1999. [BR04] Sumitha Bhandarkar and A. L. Narasimha Reddy, "TCP-DCR: Making TCP Robust to Non-Congestion Events", In the Proceedings of Networking 2004 conference, May 2004. Extended version available as tech report TAMU-ECE-2003-04. [BSRV04] Sumitha Bhandarkar, Nauzad Sadry, A. L. Narasimha Reddy and Nitin Vaidya, "TCP-DCR: A Novel Protocol for Tolerating Wireless Channel Errors", to appear in IEEE Transactions on Mobile Computing. [GPL04] Ladan Gharai, Colin Perkins and Tom Lehman, "Packet Reordering, High Speed Networks and Transport Protocol Performance", ICCCN 2004, October 2004. [Jac88] V. Jacobson, "Congestion Avoidance and Control", Computer Communication Review, vol. 18, no. 4, pp. 314-329, Aug. 1988. ftp://ftp.ee.lbl.gov/papers/congavoid.ps.Z.
[JIDKT03] S. Jaiswal, G. Iannaccone, C. Diot, J. Kurose, and D.
Towsley, "Measurement and Classification of Out-of-Sequence Packets in a Tier-1 IP Backbone," Proceedings of IEEE INFOCOM, 2003.
[KM02] I. Keslassy and N. McKeown, "Maintaining packet order in twostage switches," Proceedings of the IEEE Infocom, June 2002 [MAF05] A. Medina, M. Allman, S. Floyd. Measuring the Evolution of Transport Protocols in the Internet. ACM Computer Communication Review, 35(2), April 2005. [NS-2] ns-2 Network Simulator. http://www.isi.edu/nsnam/ [Pax97] V. Paxson, "End-to-End Internet Packet Dynamics," Proceedings of ACM SIGCOMM, September 1997. [RFC896] Nagle, J., "Congestion control in IP/TCP internetworks", RFC 896, January 1984. [RFC1122] Braden, R., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, October 1989. [RFC2883] Floyd, S., Mahdavi, J., Mathis, M., and M. Podolsky, "An Extension to the Selective Acknowledgement (SACK) Option for TCP", RFC 2883, July 2000.
[RFC2960] R. Stewart, Q. Xie, K. Morneault, C. Sharp, H.
Schwarzbauer, T. Taylor, I. Rytina, M. Kalla, L. Zhang, V. Paxson. Stream Control Transmission Protocol. October 2000. [RFC3465] Allman, M., "TCP Congestion Control with Appropriate Byte Counting (ABC)", RFC 3465, February 2003. [RFC3522] Ludwig, R. and M. Meyer, "The Eifel Detection Algorithm for TCP", RFC 3522, April 2003. [RFC3708] Blanton, E. and M. Allman, "Using TCP Duplicate Selective Acknowledgement (DSACKs) and Stream Control Transmission Protocol (SCTP) Duplicate Transmission Sequence Numbers (TSNs) to Detect Spurious Retransmissions", RFC 3708, February 2004. [RFC4015] Ludwig, R. and A. Gurtov, "The Eifel Response Algorithm for TCP", RFC 4015, February 2005.
[RFC4138] Sarolahti, P. and M. Kojo, "Forward RTO-Recovery (F-RTO):
An Algorithm for Detecting Spurious Retransmission Timeouts with TCP and the Stream Control Transmission Protocol (SCTP)", RFC 4138, August 2005.
[ZKFP03] M. Zhang, B. Karp, S. Floyd, L. Peterson, "RR-TCP: A Reordering-Robust TCP with DSACK", in Proceedings of the Eleventh IEEE International Conference on Networking Protocols (ICNP 2003), Atlanta, GA, November, 2003.
Authors' Addresses
Sumitha Bhandarkar
Dept. of Elec. Engg.
College Station, TX 77843-3128Phone: (512) 468-8078 EMail: firstname.lastname@example.com URL: http://students.cs.tamu.edu/sumitha/ A. L. Narasimha Reddy Professor Dept. of Elec. Engg. 315C WERC College Station, TX 77843-3128 Phone: (979) 845-7598 EMail: firstname.lastname@example.com URL: http://ee.tamu.edu/~reddy/
Mark Allman
ICSI Center for Internet Research
1947 Center Street, Suite 600
Berkeley, CA 94704-1198Phone: (440) 235-1792 EMail: firstname.lastname@example.com URL: http://www.icir.org/mallman/ Ethan Blanton Purdue University Computer Science 305 North University Street West Lafayette, IN 47907 EMail: email@example.com
Full Copyright Statement
Copyright © The Internet Society (2006).
This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.
This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at firstname.lastname@example.com.
Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA).


text:
The great escape: Making art together
30-minute art sessions help colleagues free their minds.
Weeks into working from home, Alex Luff was finding aspects of his new-normal challenging. And from chatting with colleagues, he knew he wasn't alone.
So he created JLL's 30-Minute Art Escapes, an online, shared art experience where staff come together once a week to paint or sketch a picture.
"To be completely absorbed in something creative, even if only for 30 minutes, can help free your mind and bring fresh perspective to any challenge or situation," says Alex, a global marketing director in London.
Alex also invited the children and family members of JLL colleagues to share in the experience of creativity and escapism. The first session pulled in 50 participants who all stepped up to complete the brief: 'A room with a view'.
"Hearing that people and their families from all over the world –from China to London –really enjoyed it made the shared experience feel all the more worthwhile."

subset: commoncrawl


text:
Andi Schreiber refuses to disappear. In her ongoing series, "Pretty Please", she documents life as an aging suburban mom in a youth-obsessed culture. "Middle-aged mom" must be one of the least sexy descriptors around, redolent of yoga pants and stretch marks and sun-damaged skin. Yet as the years have passed, Schreiber has continued to feel young and sexual, even as she's felt that society has closed those roles to her. She says:
"When I was in my thirties I heard the expression "Invisible Forties." I couldn't imagine how sexually inconsequential I'd feel throughout this decade."
The powerful documentary style photos in "Pretty, Please" beg you to look. Honest and vibrant, they are not always comfortable. Victoria's Secret has trained us to expect sexy lingerie on a young, taut body, not on folded and stretched skin. And yet, why isn't this just as beautiful? Grow old or die, those are the only options. Why can't we appreciate the child-scarred body of a woman who wants to be seen?
Self-portraits are interspersed with images from Schreiber's life. A drop of blood on the toilet seat symbolizes her ebbing fertility; the lit interior of her closet holds neatly hung clothes and shelves of shoes, but also, stashed up and away, naked kewpie dolls, whimsical and eerie.
"You get into your 40s and things are very different, your perspective changes, and the way the world looks at you changes as well."
In "Pretty, Please" we're looking at Andi Schreiber and she's looking back. This is definitively her — her life, her body, her blood — and yet this desire to be seen, to be valued on her own terms, could also represent the scores of middle-aged women who chose family and stability and have had their sense of self sacrificed to their suburban houses, and diapers, and carpools.


text:
Our clients can be confident our core values are in line with the six key principles of Treating Customers Fairly as outlined by the FCA. These are:
- Outcome 1: Consumers can be confident they are dealing with firms where the fair treatment of customers is central to the corporate culture.
- Outcome 2: Products and services marketed and sold in the retail market are designed to meet the needs of identified consumer groups and are targeted accordingly.
- Outcome 3: Consumers are provided with clear information and are kept appropriately informed before, during and after the point of sale.
- Outcome 4: Where consumers receive advice, the advice is suitable and takes account of their circumstances.
- Outcome 5: Consumers are provided with products that perform as firms have led them to expect, and the associated service is of an acceptable standard and as they have been led to expect.
- Outcome 6: Consumers do not face unreasonable post-sale barriers imposed by firms to change product, switch provider, submit a claim or make a complaint.


text:
Finally! You Can Harness The Real Power of The ClickBank Marketplace And Have an Army of Affiliates Promoting YOUR ClickBank Products
You Can Now Grab This Awesome Piece of Software That Will Allow You to Create Multiple Affiliate Links For Additional Pages in Your ClickBank Product...
Your Affiliates Really Are Going to Love You!
From: John Thornhill & Dave Nicholson - Full Time Software & Website Developers.
If like us you are interested in creating and selling products online, I'm sure you will have heard of ClickBank, as active ClickBank vendors we owe a lot of our online success to them. We really love the way they enable us to sell our products and services online on complete autopilot.
We also love the fact they take care of everything, from payment processing to delivering products to handling refunds. But the best thing about ClickBank is that we are able to tap into their 100,000+ affiliate network. This is what makes ClickBank so successful, they put affiliates and vendors (sellers) together with great success and this is why we love them so much.
Why ClickBank? Here's Just a Few Reasons...
You don't need to have a merchant account or even a PayPal account. ClickBank take care of payments on your behalf.
You don't need to install any complicated affiliate programs. ClickBank has their own affiliate platform built in!
You don't have to worry about paying your affiliates, ClickBank does this for you on your behalf.
You don't have to worry about getting paid, ClickBank will pay you promptly every single week.
Any affiliates can instantly promote your product with no need to fill in any long winded drawn out forms.
ClickBank will help drive traffic to your product by placing your product in the ClickBank marketplace.
Sounds Perfect Doesn't it?
Well it's not, while we both love ClickBank and owe a lot of our success to them, there is one fundamental flaw with they way their 'hoplink' system operates and that is affiliates can only promote your main 'hoplink'.
This is a flaw that we believe can really hurt your business and we will explain why, imagine this scenario - A highly successful marketer sees your product in the ClickBank Marketplace and contacts you in the hope of doing a massive promo for you, he reviews your product and loves it. He then says the dreaded words "Can you set me up a personalized discount page for my subscribers please?" And this is where the problem begins as it can't be done via the regular ClickBank control panel.
Sure you can create a discount page and set up a discounted product at yourproduct.com/discount but your affiliates can only ever promote your main sales page so that page is useless for affiliates, so that successful marketer has now passed you by... Until Now!
Allow me to explain...
We Were Forced To Create This Product!
We have a number of products on ClickBank, and last year we approached a big name Super Affiliate to ask if he would promote one of our products that we had just released.
The product sold for $197 during launch week then went up to $247 after launch. The Super Affiliate insisted he would promote our product but only if we set things up so he could promote at the original discounted launch price.
We had a dilemma... We knew his promo would bring in thousands but we couldn't put the price back down on the main sales page as we had just put it up, plus The Super Affiliate wanted an 'exclusive discount' to offer his subscribers.
We decided that we simply had to set this up no matter what it cost. We knew there were products out there that could help us create special discount pages but every time we found something we found it either didn't work, was too complicated, or was unreliable.
So we decided to create one of our own that was Simple To Use, Effective and Reliable. A few weeks later we had created ClickBank Affiliate Master. We got to work and set The Super Affiliates personalized sales page up, gave him his special link and he generated $20,000 in sales from a single broadcast email.
Since then we have generated numerous discount pages on most of our products for our best performing affiliates and the results have been staggering. You see this is win win because...
Your affiliate can offer their subscribers your product at a discounted rate. Your subscribers love you as you are doing your very best to secure them the best deal.
You make a TON of extra sales that you wouldn't normally have made. In fact over time most of your sales will come from discounted products.
You can approach affiliates and ask them if they would like a personalized special discount page set up.
Affiliates love it when they have a personalized page with their name on that they can send to their subscribers.
We Just Wish We Had Created This Sooner!
I really do wish we had created this sooner, you see while we used to do well on ClickBank, we now do unbelievably well. In fact most of our ClickBank sales are for discounted products that our affiliates are promoting.
We have set up a ton of special discount pages for our top affiliates and the sales are flying in. Every time we contact a potential JV partner we always say something like "If you wish I could set you up a special personalized discount page, this will see your commissions soar".
Now if you were an affiliate that would sound tempting wouldn't it? Well, we have been doing it for years now with great success!
We Have Created The Perfect Program
To Help All ClickBank Vendors
Yes, after 6 long months we have created what we believe is the perfect system to help you maximize sales.
Not only do you have access to this perfect piece of kit that enables you to create as many discounted pages as you like, but you will also receive all the training you need to set this up, not that you need any training, it's so simple!
You see there are no complicated databases to fill in or scripts to create, all you have to do is upload, then login to your admin panel and you're good to go!
Here's Just a Few of The Benefits of
ClickBank Affiliate Master
There are no complicated databases to install and you don't have to mess about with complicated PHP code.
You can be up and running in just a few minutes, just upload, login to your admin panel to add your details and you're good to go.
We will show you how to use this program to maximize your sales. We have earned over $100,000 in extra sales in only 6 months without really trying.
You can generate a custom affiliate URL for your affiliates.
You can generate a custom affiliate page where your affiliates can enter their ClickBank ID and get their custom link.
You can customize your affiliates page very simply.
You can set up as many pages and products as you like on a single ClickBank account.
PLUS! We also put our money where our mouth is...
Try ClickBank Affiliate Master for 30 days and if your ClickBank sales haven't soared let us know and you can have all of your money back NO QUESTIONS ASKED!
There is no risk whatsoever, grab this awesome offer RIGHT NOW for just a small, ONE-TIME-ONLY investment. You have a FULL 30 Days Money Back Guarantee…
So What Are You Waiting For?
Get Instant Access Right Now!
Get ClickBank Affiliate Master For a Special One Time Only Payment Today!
YES John & Dave - I Want ClickBank Affiliate Master!
I understand that by placing my secure order today, I will be getting instant access to ClickBank Affiliate Master.
You've made it a very easy decision with your 100% iron-clad money back guarantee and I'm ready to start right now, so I'm clicking the secure order button below.
I understand that this is a One Time Only Payment for Complete Access to ClickBank Affiliate Master.
Get Instant Access Now For Only $67
Payments are made through ClickBank, a secure online retailer.
As soon as you have purchased, we will send you your download details instantly.
Together with ClickBank Affiliate Master and your new army of affiliates, you simply can't fail to succeed!
ClickBank is the retailer of products on this site. CLICKBANK® is a registered trademark of Click Sales Inc., a Delaware corporation located at 1444 S. Entertainment Ave., Suite 410 Boise, ID 83709, USA and used by permission. ClickBank's role as retailer does not constitute an endorsement, approval or review of these products or any claim, statement or opinion used in promotion of these products.


text:
Sponsored Link •
The Design Forum, Java Answers Forum, and Jini Forum have moved. To participate in these forums, please visit them at their new location: http://www.artima.com/forums/index.jsp You can also browse the legacy postings of the Design Forum, Java Answers Forum, and Jini Forum, which were made from January, 1998 through February, 2002. Browse the Legacy Forum PostsBrowse the legacy forum posts via these links:
Search the Legacy Forum PostsTo search the legacy forums, type what you're looking for into the edit box and press the "Go" button.
Examples of correct boolean expressions are: cat and dog, cat
not dog, cat or (dog not nose). You can also:
About the Legacy Forum PostsFrom January 1998 through February 2002, I hosted three discussion forums at Artima.com. I created the Design Forum to accompany my Design Techniques column in JavaWorld, and to facilitate discussion about object-oriented design in general. I created the Jini Forum to accompany my Jiniology column in JavaWorld, and provide a space for general discussion about Jini. And I created the Java Answers Forum to serve as a place where Java programmers could ask and answer each other's questions. These three forums were based on a CGI script written in Perl by Matt Wright, then a high school student, who made several Perl CGI scripts available for free on the web. I had to hack this script rather heavily to get it to look presentable. The script worked reasonably well, but had several problems. The main problem was that instead of storing the forum data in a database, the script created a new HTML page for each post. This scheme made it rather difficult for me to make changes to the header, the footer, or the general look and feel of the pages, because to do so I had to process thousands of HTML files. Another serious problem was that there was no easy way to delete posts. As a result, I usually did not risk breaking a forum topic by trying to remove off-topic posts. But search engines inevitably indexed the off-topic posts, which brought more people in looking for something off-topic and making more off-topic posts in reply to the first one. These off-topic posts grew like tumors on a few forum topics. For example, the forum topic that was supposed to be a discussion of my first Jiniology article ended up having over 3000 requests for sample Java Certification exams. In February of 2002, I replaced the Perl CGI-based forums with one based on Java Servlets and JSPs. These forums are based on Jive Software's forum product, which uses a database to store forum data. You can participate in these forums at the URL specified above. Because the legacy forums had a lot of interesting material in them, I processed them to make them inactive and remove any off-topic posts, and placed them here. |
Sponsored Links


text:
by Jim DeFed
(1 year ago) |
19 Aug, 2022
When 38 jetliners bound for the United States were forced to land at Gander International Airport in Canada by the closing of U.S. airspace on September 11, the population of this small town on Newfoundland Island swelled from 10,300 to nearly 17,000. The citizens of Gander met the stranded passengers with an overwhelming display of friendship and goodwill.
As the passengers stepped from the airplanes, exhausted, hungry and distraught after being held on board for nearly 24 hours while security checked all of the baggage, they were greeted with a feast prepared by the townspeople. Local bus drivers who had been on strike came off the picket lines to transport the passengers to the various shelters set up in local schools and churches. Linens and toiletries were bought and donated. A middle school provided showers, as well as access to computers, email, and televisions, allowing the passengers to stay in touch with family and follow the news.
More books from United States of America
More books from Read Around North America Challenge


text:
Famous Creators on the Fear of Failure
By Maria Popova
While failure may be an integral prerequisite for true innovation, the fact remains that most of us harbor a deathly fear of it — the same psychological mechanisms that drive our severe aversion to being wrong, only amplified. That fear is the theme of this year's student work exhibition at Stockholm's Berghs School of Communication and, to launch it, they asked some of today's most beloved creators — artists, designers, writers — to share their experiences and thoughts on the subject. While intended as advice for design students, these simple yet important insights are relevant to just about anyone with a beating heart and a head full of ideas — a much-needed reminder of what we all rationally know but have such a hard time internalizing emotionally.
When you put love and enthusiasm into your work, even if people don't see it, they realize that it is there, that you did this with all your body and soul." ~ Paulo Coelho
It is very important to embrace failure and to do a lot of stuff — as much stuff as possible — with as little fear as possible. It's much, much better to wind up with a lot of crap having tried it than to overthink in the beginning and not do it." ~ Stefan Sagmeister
What it comes down to is accepting the fact that many ideas and many solutions that we provide to our clients may always, or sometimes, fail. The trick, I think, is to A) accept it and B) have the courage to accept it and move forward with what you believe in." ~ Rei Inamoto
But my favorite has to be Milton Glaser:
A characteristic of artistic education is for people to tell you that you're a genius. […] So everybody gets this idea, if you go to art school, that you're really a genius. Sadly, it isn't true. Genius occurs very rarely. So the real embarrassing issue about failure is your own acknowledgement that you're not a genius, that you're not as good as you thought you were. […] There's only one solution: You must embrace failure. You must admit what is. You must find out what you're capable of doing, and what you're not capable of doing. That is the only way to deal with the issue of success and failure because otherwise you simply would never subject yourself to the possibility that you're not as good as you want to be, hope to be, or as others think you are." ~ Milton Glaser
Explore all the videos on the exhibition site and feel free to share your own recipe for dealing with failure in the comments below.
Published May 12, 2011


text:
Quick Launch Guide
This guide outlines key steps to help you launch Workplace successfully to 500 people or less.
You're here because you decided to transform the way your organization connects, communicates, and collaborates by using Workplace. That's very exciting, and we can't wait for you to get started.
Changing the way your organization works is a big project, but we're here to help. This Quick Launch Guide was created based on thousands of successful Workplace deployments. Use it to plan and execute a Workplace launch fast.
This guide will walk you through:
- Steps to take before getting started
- Workplace technical setup
- Recruiting and training your champions
- Building your group structure
- Getting executives and people managers engaged
- Communicating your Workplace launch
Before you get started
Get executive buy-in and engagement
Align your executives on why introducing Workplace supports the goals of your organization. Based on the goals, encourage them to model the behaviors you want to see on Workplace. For example, if leaders want to hear feedback from their frontline and customer facing employees, they should engage with those employees directly on Workplace with polls and Live Q&As.
For more guidance on defining business drivers and the value Workplace will bring to your organization, see the Value Assessment Workshop.
Create a Workplace project team
You'll need to build a Workplace project team to help plan out and execute your launch. A typical Workplace project team consists of:
- Executive sponsor: to drive buy-in and direction from the top of the organization.
- Project manager: to manage the project and coordinate resources during implementation.
- IT/HR leads: to import all employees and integrate with an identity provider/SSO if applicable.
- Internal communications lead: to plan and execute your internal communication strategy.
- Workplace Champions: to define Workplace content for launch and be platform advocates. We'll get into Workplace Champions in more detail a little later.
1. Workplace technical setup
You'll likely need the help of IT teams in your company to set up your Workplace and get you ready for launch. Have them follow these steps to configure Workplace for your organization:
- If your users will use one or more business domains to access Workplace (e.g. @company.com), ensure these domains are marked as verified in the Workplace Admin Panel.
- Decide how your users will be created in Workplace: manually, in bulk via CSV upload or by connecting to a Cloud directory.
- Create users in Workplace but hold off on sending invitations. We recommend you build your groups and prepare your organization before inviting employees to join. Learn about the account lifecycle in the Workplace Technical Resources.
- By default Workplace will ask users to create a password for their account at their first access. Workplace Admins on the Advanced plan can enable single sign on (SSO) as an extra security layer.
- When you're ready to launch, you can invite your users to access Workplace. Users with email addresses will receive a customizable email invitation encouraging people to claim their accounts. For email-less users you may need to distribute one-time access codes for their first login to Workplace.
Pro-tip: Integrate Workplace with other work tools your organization uses before you launch. Content and file sharing integrations are a great place to start. They make it easy to share and collaborate on files in Workplace. See available integrations in the Integrations Directory.
2. Workplace champions2. Workplace champions
Select a small and diverse group of people in your organization and enlist their support in building groups, driving adoption, and educating the rest of the organization on how to use Workplace.
Choosing your champions:
Select roughly 5 champions for every 100 employees in your company. Champions should be chosen for their influence and early adopter behaviors. People managers make great champions because they influence working behaviors in their teams.
Organizations with frontline employees should make sure that frontline managers are involved as champions early in the rollout. They are key to motivating their direct reports and bringing people on board. They will also play an important role supporting people if they need help accessing their account or learning to use Workplace.
Preparing your champions:
- Use the email template in the Quick Launch Communication Plan (step 4) to notify your champions of their role in the launch
- Send them to the Workplace User Essentials course to learn about how to use Workplace
- Give them early access by inviting them to Workplace
- Create a secret Workplace group called "Workplace Champions" and add them to it. You'll use that group to communicate with champions before, during, and after the launch.
3. Create groups
Create a core set of groups and assign members to them before inviting your organization to Workplace. When creating groups, you have two things to consider:
- Privacy: How people join your group and who can see posts
- Posting permissions: Who can post in the group
- Open: Anyone can join and see members and posts
- Closed: Anyone can request to join and only members can see posts.
- Secret: People have to be invited to join and see posts. Secret groups don't show up in search, only members and admins can see they exist.
Posting permissions
- Anyone can post
- Posts require admin approval
- Only admins can post
You'll be using People Sets to assign members to your groups based on criteria such as department, job title, location and more. Learn how to create People Sets in the Workplace Help Center.
Core groups can be structured around 3 types of communication:
1. Company communication
Company-wide announcement and discussion groups can streamline your communications and build stronger connections from headquarters to the frontline.
- Create an open "[Company Name] Announcements" group.
- Add other admins to manage the group when you're away
- Make it a default group so all employees are automatically joined
- Set posting permissions to admins only
- Use the group to share important updates and information across the company
- Create open regional announcement groups such as "[Location] Announcements"
- Add other admins to manage the group when you're away
- Set posting permissions to admins only
- Use People Sets (synced with Workplace profiles) to assign members to groups based on location
- Use this group to share regional news and updates
- Create open company-wide and regional discussion groups like "[Company Name] Discussion" and "[Office Location] discussion"
- Add other admins to manage the group when you're away
- Set posting permissions to either anyone can post, or posts require admin approval
- Make your company-wide discussion group a default group. Use People Sets (synced with Workplace profiles) to assign members to regional groups based on location
- Encourage employees to share questions and start work-related discussions in this group.
- Pro-tip: Create open social groups to recognize people's contributions and performance. The group will be a space for anyone in the company to give kudos to a colleague.
- Set posting permissions to anyone.
2. Common and repetitive workflows
Use groups to streamline processes and workflows, such as:
- HR Q&A group or IT Helpdesk group: To help people find answers to their questions.
- Facilities group: To quickly and efficiently report equipment and facilities issues.
- Shift cover group: To allow frontline employees to request coverage or pick up available shifts. Learn more about Shift Cover in the Help Center.
3. Team collaboration
This is where everyone's day-to-day work gets done. People will be using their team and department groups to share updates on their work, collaborate on files, communicate via text, voice, and video chat and much more.
- Create closed groups for teams and departments in your organization and make the manager an admin.
- Set posting permissions to anyone.
- Encourage champions to create closed groups for each one of their projects as well as secret groups for communication with managers or direct reports
Pro-tip: Encourage people managers and department heads to create team and department announcement groups like "Marketing Announcements", "New Product Launches" and "Sales Wins". These groups can be used to keep everyone informed and up-to-date on all of the work being done across the organization.
4. Engage executives and people managers4. Engage executives and people managers
Executives will be using Workplace to share updates, keep employees informed, and communicate across the organization. Make sure they know how to use Workplace and how it can benefit them and the company.
Here are some resources you can share with your executives:
Get people managers involved in the Workplace launch early on. The more they know about Workplace, the more their teams can benefit from using the tool. Here are some resources you can share with them:
- People Manager Guide: Quick guide to help people managers get started in Workplace
- Managing Projects in Workplace: Learn how to use team and project groups to manage your work in Workplace
- Managing your team with Workplace from Meta: Learn how to run your team or department through Workplace, ranging from your 1:1 relationship with your direct reports all the way up to managing your relationship with your external stakeholders.
5. Launch communications
Get employees excited for launch with communications that are focused on the value Workplace will bring to their day-to-day. A comprehensve communication strategy is key to getting more of your organization onboard. To help you, we created The Workplace Launch Kit with key assets such as template communications, posters, email banners, activation instructions and more, to help you drive Workplace adoption on launch day and beyond.
6. Send out invitationsStep 6: Send out invitations
Once you've set up your groups and communicated the launch to your team, you're ready to send out invitations. Use the communications outlined in the Quick Launch Communication Plan to share profile activation information and to continue to encourage employees to join and engage on Workplace after launch day.
Make sure employees know about the wide variety of help and education resources available to them. Share links to Workplace getting started content to help employees get up to speed with Workplace fast:
- New User Essentials: This self-paced course has everything your employees need to start working in Workplace
- New User Guide: A lightweight 7-step guide to getting started as a Workplace user
- Group Admin Guide: Anyone who creates a group in Workplace becomes a group admin. Learn about the group admin role and the features and functionality available to help you manage your Workplace groups
- Managing Notifications: Learn how to turn down the noise so you can stay on top of what's important.
Other helpful resources
After launching Workplace, be sure to check out a variety of other resources to help you measure the success of your launch, understand the Workplace Admin Panel, and drive adoption and engagement after launch.


text:
Hospital water taps contaminated with bacteria
New research has found significantly higher levels of infectious pathogens in water from faucet taps with aerators compared to water from deeper in the plumbing system, which Sweden's Bluewater believes underlines the need for additional research to discover how water contamination threatens patient health.
Contaminated water poses an increased risk for infection in immunocompromised patients., according to a study published in the February issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.
"Aerators are a reservoir for drug-resistant bacteria and a source of infection for patients at risk," said Maria Luisa Cristina, PhD, a lead author of the study. "Safe water is vital to ensuring patient safety where waterborne infections increase morbidity, mortality, treatment costs, compensation claims and prolong hospital stays."
Researchers from the University of Genova in Italy and collaborating universities studied cold and hot water samples at two tertiary care hospitals for a year from faucets used by healthcare professionals for handwashing, surgical washing, and washing of medical equipment.
This study assessed growth of bacteria at both the faucet and deeper within the water distribution system. Cold and hot water sampling was carried out first with the aerators in faucets in place to assess the risk at each outlet point and then after disinfecting and flame-sterilizing the outlet point and letting the water run for two minutes to analyze the microbiological features of the plumbing system.
Researchers found the total microbial load was up to 10 times greater when aerators were in place than after they had been sterilized. Their findings show that opportunist micro-organisms like Legionella spp., Acinetobacter spp. and other Gram-negative bacteria were significantly higher at the faucet than in the plumbing system. Throughout the study, researchers consistently noted chlorine levels that were too low and hot water temperatures that were below the minimal temperature needed to prevent the growth of Legionella. Both of these factors promote the growth of waterborne pathogens.
In a commentary published alongside the study, Tara Palmore, MD, notes the need for additional research on the topic: "Hospitals tend to have large, complex waterworks with low-flow areas that produce stagnation and biofilm formation; hot and cold water temperatures that are not well regulated may be ideal for bacterial growth...the work of Cristina et al. is valuable in quantifying the frequency, magnitude, and location of the potential hazard to patients from hospital water in their facilities. There is still a significant gap in our understanding of how and when such risk translates to patient infections."


text: Sponsored Tweet With more than 5,300 twitter followers who are always on a look out for the latest iOS apps, sponsored tweet is a great way to advertise your app and engage people. The response to your ad campaign is instant and it is very easy to set up. Just view our listing on BuySellAds and click "Add to cart". … Read More


text:
Tanzania Destinations olduvai gorge
Over the last thirty years or so, it has become increasingly apparent that Africa is probably the "Cradle of Mankind" From Africa they spread out to populate the rest of Earth. Remains of the earliest humans were found in Oldupai Gorge.
Olduvai Gorge is a site in Tanzania that holds the earliest evidence of the existence of human ancestors. Paleoanthropologists have found hundreds of fossilized bones and stone tools in the area dating back millions of years, leading them to conclude that humans evolved in Africa.
Olduvai is a misspelling of Oldupai, a Maasai word for a wild sisal plant that grows in the area. The gorge is located in the Great Rift Valley, between the Ngorongoro Crater and the Serengeti National Park. It is 30 miles from Laetoli, another fossil-rich area. Olduvai Gorge was formed about 30,000 years ago, the result of aggressive geological activity and streams.
The steep ravine is about 30 miles (48.2 km) long and 295 feet (89.9 meters) deep, not quite large enough to be classified as a canyon. A river cuts through several layers to form four individual beds, with the oldest estimated at about 2 million years old.
At Laetoli, west of Ngorongoro Crater, hominid footprints are preserved in volcanic rock 3.6 millions years old and represent some of the earliest signs of mankind in the world. Three separate tracks of a small-brained upright walking early hominid. Australopithecus afarensis, a creature about 1.2 to 1.4 meters high, were found. Imprints of these are displayed in the Oldupai museum.
More advanced descendants of Laetoli's hominids were found further north, buried in the layers of the 100 meters deep Oldupai Gorge. Excavations, mainly by the archaeologist Louis and Mary Leakey, yielded four different kinds of hominid, showing a gradual increases in brain size and in the complexity of their stone tools. The first skull of Zinjanthropus, commonly known as 'Nutcracker Man' who lived about 1.75 millions years ago, was found here. The most important find include Home habilis, Zinjathropus and the Laetoli footprints.


text:
The "Sovereignty Flag" Hawaiian Fight Gear HFG Compression Shorts. Long Style.
Compression fiber technology: improve blood flow to your working muscles and accelerate your recovery time. Specific thermal-welding seamless assembly in order to deliver a soft and smooth sensation on your skin. High quality stitching for unmatched durability.
Effective fiber-based moisture management system which allows to actively draw perspiration away. Rubber band for an absolute fit: ensure a full coverage of your thigh.
4-way fabric offering an improved adjustment and keep its shape.
HFG logos on the front and back with Sovereignty Flag on the front panel! Great for training and competition for all martial arts. The very best compression shorts on the market!!!!


text:
Down N' Out: Pokeburgers Pop Up Store open until Saturday 3rd September 2016. Sir John Young Hotel, 557 George Street, Cnr Liverpool Street, Sydney NSW.
Photos by Hai taken with Canon D70 / Last Photo by Spooning Australia
Pokeman fans alert! Whether you've loved it for twenty years, two months or barely know what Pokemon comes after Pikachu - we all can appreciate the efforts Down N' Out have made to capture the magic of the popular cartoon series and games that's been around for twenty years.
Down N' Out have created THE ultimate food craze - designing three burgers inspired by Ash's Pikachu, and two starter Pokemon - the grass type Bulbasaur and the fire type, Charmander. These $15 burgers have been dubbed the "Pokeburger" and were launched 22nd August.
Each Pokeburger has it own flavour profile. Although all contain a juicy wagyu beef patty, they all have different toppings. Pikachu is stuffed with Down N' Out famous 'tiger fries' which makes sense since he is electric type. Bulbasaur contains more fresh greens - lettuce, onions and pickles with a broccoli to replicate the bulb. Charmander is slightly spicy - crispy bacon drenched in a spicy mayo and dripping with melted volcanic cheese.
With its tinted buns and cute character faces (and Pikachu's ears!) Down N' Out have been flat out with the high demand - now opening on Mondays to keep up. Most burgers are sold out within minutes of the store opening (between 12pm-3pm and 5pm-9pm) and another thing you have to factor in - customers do not get to choose their burger, everyone gets a Pokeburger flavour at random.
In our case, our group of three managed to get three Charmanders. Considering ourselves lucky to even get a Pokeburger, we were impressed with how photo-worthy and cute the burgers were.
Having abit of fun, we replicated Charmander's flame tail by sparking a lighter to create a small fire at the end of a bacon strip.
And good news. According to Food Beast, the owners of Down N' Out are creating concepts for Snorlax, Voltorb and Clefairy Pokeburgers. I personally can't wait for the Clefairy ones, I can imagine it to have puffs of pink fairyfloss everywhere or Moon stone designs.
Currently there are only a limited amount of burgers available with the pop-up store ending the Pokeburger craze 3rd September 2016. Come down and enjoy them while you can - take a Pokesick day if you have to! It is well worth it to catch them all!


text:
BHI Senior Living Terms of Service
BHI Senior Living provides this website, its "Service" to you, subject to the following Terms of Service ("TOS"), which may be updated by us from time to time without notice to you. In addition, when using particular BHI Senior Living Services, you and BHI Retirement Communities shall be subject to any posted guidelines or rules applicable to such Services, which may be posted from time to time. All such guidelines or rules are hereby incorporated by reference into the TOS.
BHI Senior Living currently provides users with access to a large collection of informational resources, including, various communications tools (which can be used to create publically available information, otherwise known as "Content"). Unless explicitly stated otherwise, any new features that augment or enhance the current Service, including the release of new BHI Senior Living properties, shall be subject to the TOS. You understand and agree that the Service is provided "AS-IS" and that BHI Senior Living assumes no responsibility for the timeliness, deletion, mis-delivery or failure to store any user communications or personalization settings.
In order to use the Service, you must obtain access to the World Wide Web, either directly or through devices that access Web-based content, and pay any service fees associated with such access. In addition, you must provide all equipment necessary to make such connection to the World Wide Web, including a computer and modem or other access device.
The information provided on BHI Senior Living is presented as helpful general information and is not intended as advice and should not be considered as such.
You must be at least 18 years of age to access and view interactive areas (Message Boards) of BHI Senior Living.
BHI Senior Living PRIVACY POLICY
Registration Data and certain other information about you is subject to our Privacy Policy.
You understand that all information, data, text, software, music, sound, photographs, graphics, video, messages or other materials ("Content"), whether publicly posted or privately transmitted, are the sole responsibility of the person from which such Content originated. This means that you, and not BHI Senior Living, are entirely responsible for all Content that you upload, post, email or otherwise transmit via the Service. BHI Senior Living may not always control the Content posted via the Service and, as such, does not guarantee the accuracy, integrity or quality of such Content. You understand that by using the Service, you may be exposed to Content that is offensive, indecent or objectionable. Under no circumstances will BHI Senior Living be liable in any way for any Content, including, but not limited to, for any errors or omissions in any Content, or for any loss or damage of any kind incurred as a result of the use of any Content posted, emailed or otherwise transmitted via the Service.
You agree to not use the Service to:
a. upload, post, email or otherwise transmit any Content that is unlawful, harmful, threatening, abusive, harassing, tortious, defamatory, vulgar, obscene, libelous, invasive of another's privacy, hateful, or racially, ethnically or otherwise objectionable;
b. harm minors in any way;
c. impersonate any person or entity, including, but not limited to, a BHI Senior Living official, forum leader, guide or host, or falsely state or otherwise misrepresent your affiliation with a person or entity;
d. forge headers or otherwise manipulate identifiers in order to disguise the origin of any Content transmitted through the Service;
e. upload, post, email or otherwise transmit any Content that you do not have a right to transmit under any law or under contractual or fiduciary relationships (such as inside information, proprietary and confidential information learned or disclosed as part of employment relationships or under nondisclosure agreements);
f. upload, post, email or otherwise transmit any Content that infringes any patent, trademark, trade secret, copyright or other proprietary rights ("Rights") of any party;
g. upload, post, email or otherwise transmit any unsolicited or unauthorized advertising, promotional materials, "junk mail," "spam," "chain letters," "pyramid schemes," or any other form of solicitation, except in those areas (such as shopping rooms) that are designated for such purpose;
h. upload, post, email or otherwise transmit any material that contains software viruses or any other computer code, files or programs designed to interrupt, destroy or limit the functionality of any computer software or hardware or telecommunications equipment;
i. disrupt the normal flow of dialogue, cause a screen to "scroll" faster than other users of the Service are able to type, or otherwise act in a manner that negatively affects other users' ability to engage in real time exchanges;
j. interfere with or disrupt the Service or servers or networks connected to the Service, or disobey any requirements, procedures, policies or regulations of networks connected to the Service;
k. intentionally or unintentionally violate any applicable local, state, national or international law, including, but not limited to, regulations promulgated by the U.S. Securities and Exchange Commission, any rules of any national or other securities exchange, including, without limitation, the New York Stock Exchange, the American Stock Exchange or the NASDAQ, and any regulations having the force of law;
l. "stalk" or otherwise harass another; or
m. collect or store personal data about other users.
You acknowledge that BHI Senior Living may not pre-screen Content, but that BHI Senior Living and its designees shall have the right (but not the obligation) in their sole discretion to refuse or move any Content that is available via the Service. Without limiting the foregoing, BHI Senior Living and its designees shall have the right to remove any Content that violates the TOS or is otherwise objectionable. You agree that you must evaluate, and bear all risks associated with, the use of any Content, including any reliance on the accuracy, completeness, or usefulness of such Content. In this regard, you acknowledge that you may not rely on any Content created by BHI Senior Living or submitted to BHI Senior Living, including without limitation information in BHI Senior Living Message Boards and in all other parts of the Service.
You acknowledge and agree that BHI Senior Living may preserve Content and may also disclose Content if required to do so by law or in the good faith belief that such preservation or disclosure is reasonably necessary to: (a) comply with legal process; (b) enforce the TOS; (c) respond to claims that any Content violates the rights of third-parties; or (d) protect the rights, property, or personal safety of BHI Senior Living, its users and the public.
You understand that the technical processing and transmission of the Service, including your Content, may involve (a) transmissions over various networks; and (b) changes to conform and adapt to technical requirements of connecting networks or devices.
Recognizing the global nature of the Internet, you agree to comply with all local rules regarding online conduct and acceptable Content. Specifically, you agree to comply with all applicable laws regarding the transmission of technical data exported from the United States or the country in which you reside.
PUBLIC CONTENT POSTED TO BHI Senior Living
(a) For purposes of the TOS, "publicly accessible areas of the Service" are those accessible by the general public. By way of example, a publicly accessible area of the Service would include BHI Senior Living User Comments as they relate to a posted column.
(b) With respect to Content you elect to post to publicly accessible areas of the Service, you grant BHI Senior Living the royalty-free, perpetual, irrevocable, non-exclusive and fully sublicensable right and license to use, reproduce, modify, adapt, publish, translate, create derivative works from, distribute, perform and display such Content (in whole or part) worldwide and/or to incorporate it in other works in any form, media, or technology now known or later developed.
You agree to indemnify and hold BHI Senior Living, and its subsidiaries, affiliates, officers, agents, co-branders or other partners, volunteers and employees, harmless from any claim or demand, including reasonable attorneys' fees, made by any third party due to or arising out of Content you submit, post to or transmit through the Service, your use of the Service, your connection to the Service, your violation of the TOS, or your violation of any rights of another.
You agree not to reproduce, duplicate, copy, sell, resell or exploit for any commercial purposes, any portion of the Service, use of the Service, or access to the Service.
You acknowledge that BHI Senior Living may establish general practices and limits concerning use of the Service, including without limitation the maximum number of days that email messages, news content, roommate listings, or other uploaded Content will be retained by the Service, the maximum number of email messages that may be sent from or received by an account on the Service, the maximum size of any email message that may be sent from or received by an account on the Service, the maximum disk space that will be allotted on BHI Senior Living's servers on your behalf, and the maximum number of times (and the maximum duration for which) you may access the Service in a given period of time. You agree that BHI Senior Living has no responsibility or liability for the deletion or failure to store any messages and other communications or other Content maintained or transmitted by the Service. You acknowledge that BHI Senior Living reserves the right to log off accounts that are inactive for an extended period of time. You further acknowledge that BHI Senior Living reserves the right to change these general practices and limits at any time, in its sole discretion, with or without notice.
BHI Senior Living reserves the right at any time and from time to time to modify or discontinue, temporarily or permanently, the Service (or any part thereof) with or without notice. You agree that BHI Senior Living shall not be liable to you or to any third party for any modification, suspension or discontinuance of the Service.
You agree that BHI Senior Living, in its sole discretion, may terminate your password(s), account(s) (or any part thereof) or use of the Service, and remove and discard any Content within the Service, for any reason, including, without limitation, for lack of use or if BHI Senior Living believes that you have violated or acted inconsistently with the letter or spirit of the TOS. BHI Senior Living may also in its sole discretion and at any time discontinue providing the Service, or any part thereof, with or without notice. You agree that any termination of your access to the Service under any provision of this TOS may be effected without prior notice, and acknowledge and agree that BHI Senior Living may immediately deactivate or delete your account and all related information and files in your account and/or bar any further access to such files or the Service. Further, you agree that BHI Senior Living shall not be liable to you or any third-party for any termination of your access to the Service.
Your correspondence or business dealings with, or participation in promotions of, advertisers found on or through the Service, including payment and delivery of related goods or services, and any other terms, conditions, warranties or representations associated with such dealings, are solely between you and such advertiser. You agree that BHI Senior Living shall not be responsible or liable for any loss or damage of any sort incurred as the result of any such dealings or as the result of the presence of such advertisers on the Service.
The Service may provide, or third parties may provide, links to other World Wide Web sites or resources. Because BHI Senior Living has no control over such sites and resources, you acknowledge and agree that BHI Senior Living is not responsible for the availability of such external sites or resources, and does not endorse and is not responsible or liable for any Content, advertising, products, or other materials on or available from such sites or resources. You further acknowledge and agree that BHI Senior Living shall not be responsible or liable, directly or indirectly, for any damage or loss caused or alleged to be caused by or in connection with use of or reliance on any such Content, goods or services available on or through any such site or resource.
BHI Senior Living PROPRIETARY RIGHTS
You acknowledge and agree that the Service and any necessary software used in connection with the Service ("Software") contain proprietary and confidential information that is protected by applicable intellectual property and other laws. You further acknowledge and agree that Content contained in sponsor advertisements or information presented to you through the Service or advertisers is protected by copyrights, trademarks, service marks, patents or other proprietary rights and laws. Except as expressly authorized by BHI Senior Living or advertisers, you agree not to modify, rent, lease, loan, sell, distribute or create derivative works based on the Service or the Software, in whole or in part.
BHI Senior Living grants you a personal, non-transferable and non-exclusive right and license to use the object code of its Software on a single computer; provided that you do not (and do not allow any third party to) copy, modify, create a derivative work of, reverse engineer, reverse assemble or otherwise attempt to discover any source code, sell, assign, sublicense, grant a security interest in or otherwise transfer any right in the Software. You agree not to modify the Software in any manner or form, or to use modified versions of the Software, including (without limitation) for the purpose of obtaining unauthorized access to the Service. You agree not to access the Service by any means other than through the interface that is provided by BHI Senior Living for use in accessing the Service.
YOUR USE OF THE SERVICE IS AT YOUR SOLE RISK. THE SERVICE IS PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS. BHI Senior Living EXPRESSLY DISCLAIMS ALL WARRANTIES OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
b. BHI Senior Living MAKES NO WARRANTY THAT (i) THE SERVICE WILL MEET YOUR REQUIREMENTS, (ii) THE SERVICE WILL BE UNINTERRUPTED, TIMELY, SECURE, OR ERROR-FREE, (iii) THE RESULTS THAT MAY BE OBTAINED FROM THE USE OF THE SERVICE WILL BE ACCURATE OR RELIABLE, (iv) THE QUALITY OF ANY PRODUCTS, SERVICES, INFORMATION, OR OTHER MATERIAL PURCHASED OR OBTAINED BY YOU THROUGH THE SERVICE WILL MEET YOUR EXPECTATIONS, AND (V) ANY ERRORS IN THE SOFTWARE WILL BE CORRECTED.
c. ANY MATERIAL DOWNLOADED OR OTHERWISE OBTAINED THROUGH THE USE OF THE SERVICE IS DONE AT YOUR OWN DISCRETION AND RISK AND THAT YOU WILL BE SOLELY RESPONSIBLE FOR ANY DAMAGE TO YOUR COMPUTER SYSTEM OR LOSS OF DATA THAT RESULTS FROM THE DOWNLOAD OF ANY SUCH MATERIAL.
d. NO ADVICE OR INFORMATION, WHETHER ORAL OR WRITTEN, OBTAINED BY YOU FROM BHI Senior Living OR THROUGH OR FROM THE SERVICE SHALL CREATE ANY WARRANTY NOT EXPRESSLY STATED IN THE TOS.
YOU EXPRESSLY UNDERSTAND AND AGREE THAT BHI Senior Living SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO, DAMAGES FOR LOSS OF PROFITS, GOODWILL, USE, DATA OR OTHER INTANGIBLE LOSSES (EVEN IF BHI Senior Living HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES), RESULTING FROM: (i) THE USE OR THE INABILITY TO USE THE SERVICE; (ii) THE COST OF PROCUREMENT OF SUBSTITUTE GOODS AND SERVICES RESULTING FROM ANY GOODS, DATA, INFORMATION OR SERVICES PURCHASED OR OBTAINED OR MESSAGES RECEIVED OR TRANSACTIONS ENTERED INTO THROUGH OR FROM THE SERVICE; (iii) UNAUTHORIZED ACCESS TO OR ALTERATION OF YOUR TRANSMISSIONS OR DATA; (iv) STATEMENTS OR CONDUCT OF ANY THIRD PARTY ON THE SERVICE; OR (v) ANY OTHER MATTER RELATING TO THE SERVICE.
Notices to you may be made via either email or regular mail. The Service may also provide notices of changes to the TOS or other matters by displaying notices or links to notices to you generally on the Service.
COPYRIGHTS and COPYRIGHT AGENTS
If you believe that your work has been copied in a way that constitutes copyright infringement, please provide BHI Senior Living's webmaster at BHIseniorliving.org with the following information:
an electronic or physical signature of the person authorized to act on behalf of the owner of the copyright interest;
a description of the copyrighted work that you claim has been infringed;
a description of where the material that you claim is infringing is located on the site;
your address, telephone number, and email address;
a statement by you that you have a good faith belief that the disputed use is not authorized by the copyright owner, its agent, or the law;
a statement by you, made under penalty of perjury, that the above information in your Notice is accurate and that you are the copyright owner or authorized to act on the copyright owner's behalf.
The TOS constitute the entire agreement between you and BHI Senior Living and govern your use of the Service, superseding any prior agreements between you and BHI Senior Living. You also may be subject to additional terms and conditions that may apply when you use affiliate services, third-party content or third-party software. The TOS and the relationship between you and BHI Senior Living shall be governed by the laws of the State of New Jersey without regard to its conflict of law provisions. You and BHI Senior Living agree to submit to the personal and exclusive jurisdiction of the courts located within the county of Middlesex, New Jersey. The failure of BHI Senior Living to exercise or enforce any right or provision of the TOS shall not constitute a waiver of such right or provision. If any provision of the TOS is found by a court of competent jurisdiction to be invalid, the parties nevertheless agree that the court should endeavor to give effect to the parties' intentions as reflected in the provision, and the other provisions of the TOS remain in full force and effect. You agree that regardless of any statute or law to the contrary, any claim or cause of action arising out of or related to use of the Service or the TOS must be filed within one (1) year after such claim or cause of action arose or be forever barred.
The section titles in the TOS are for convenience only and have no legal or contractual effect.
Please report any violations of the TOS to our webmaster at BHIseniorliving.org
This Agreement shall be construed in accordance with the laws of the State of New Jersey, without regard to any conflict of laws provisions. Any dispute arising under this Agreement shall be resolved exclusively in the state and federal courts of the State of New Jersey, to which exclusive jurisdiction you hereby agree to submit.
You may terminate this Agreement at any time by discontinuing your use of the website. We may terminate this Agreement, and restrict your access to this website if you fail to comply with any term of this Agreement. Regardless of the basis for termination of this Agreement, our limitation of liability, your indemnity obligations, your restricted use of the information you may have downloaded here from, and the jurisdictional and governing law provisions of this Agreement shall survive.
Accessibility Statement for FOURSEASONSRETIREMENT.COM
Four Seasons Retirement Community and Patterson Riegel Advertising are committed to ensuring digital accessibility for people with disabilities. We are continually improving the user experience for everyone and applying the relevant accessibility standards.
Measures to support accessibility
The Four Seasons website has been built using the WordPress platform, which meets the Web Content Accessibility Guidelines (WCAG) version 2.0 at level AA, and the platform continually strives towards ATAG 2.0 full compliance. In addition, W3C best building practices were used during the construction of the website, including:
- Proper page content structure and hierarchy
- Design awareness and testing of color and contrast
- Descriptive title and alternate <alt> text describing all photographs and pertinent graphics
- ARIA landmarks where appropriate
- Well-formed HTML semantics including proper tags for text and tables
- Appropriate controls and navigation that allow for easy and intuitive keyboard navigation
Conformance status
The Web Content Accessibility Guidelines (WCAG) defines requirements for designers and developers to improve accessibility for people with disabilities. It defines three levels of conformance: Level A, Level AA, and Level AAA. fourseasonsretirement.com is partially conformant with WCAG 2.0 level AA. Partially conformant means that some parts of the content do not fully conform to the accessibility standard.
Technical specifications
Accessibility of fourseasonsretirement.com relies on the following technologies to work with the particular combination of web browser and any assistive technologies or plugins installed on your computer:
- JavaScript
These technologies are relied upon for conformance with the accessibility standards used.
Assessment approach
Patterson Riegel Advertising assessed the accessibility of fourseasonsretirement.com by the following approaches:
- Evaluation using the WAVE Web Accessibility Evaluation Tool


text:
Danni gets an unexpected visitor at work.
Audiobooks for Sale: Urban Legends, Things Unseen, Divine Intervention, The Lost and the Least, Distant Realms, A Wizard Family Solstice, Homecoming, Making the Cut (Use these bounty links and Chris will get a special bonus payment from Audible!)
Buy Making the Cut on Amazon (Kindle)
Buy Making the Cut on Smashwords (EPUB)
Support Chris Lester on Patreon
Podcast: Play in new window | Download
Subscribe: Apple Podcasts | RSS