text:
The University of Auckland
A. Blount
MetraTech Corp.
September 2000
Accounting Attributes and Record Formats
Status of this Memo
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
Copyright Notice
Copyright © The Internet Society (2000). All Rights Reserved.
This document summarises Internet Engineering Task Force (IETF) and International Telecommunication Union (ITU-T) documents related to Accounting. A classification scheme for the Accounting Attributes in the summarised documents is presented. Exchange formats for Accounting data records are discussed, as are advantages and disadvantages of integrated versus separate record formats and transport protocols. This document discusses service definition independence, extensibility, and versioning. Compound service definition capabilities are described.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology and Notation . . . . . . . . . . . . . . . . . . . 3 3. Architecture Model . . . . . . . . . . . . . . . . . . . . . . 4 4. IETF Documents . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1.1. RADIUS Attributes . . . . . . . . . . . . . . . . . . . . 5 4.2. DIAMETER . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2.1. DIAMETER Attributes . . . . . . . . . . . . . . . . . . . 7 4.3. ROAMOPS . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.4. RTFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.4.1. RTFM Attributes . . . . . . . . . . . . . . . . . . . . . 9 4.5. ISDN MIB . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.5.1. ISDN Attributes . . . . . . . . . . . . . . . . . . . . . 10 4.6. AToMMIB . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.6.1. AToMMIB Attributes . . . . . . . . . . . . . . . . . . . . 11 4.7. QoS: RSVP and DIFFSERV . . . . . . . . . . . . . . . . . . . 12 4.7.1. QoS: RSVP and DIFFSERV Attributes . . . . . . . . . . . . 13 5. ITU-T Documents . . . . . . . . . . . . . . . . . . . . . . . 13 5.1. Q.825: Call Detail Recording . . . . . . . . . . . . . . . . 13 5.2. Q.825 Attributes . . . . . . . . . . . . . . . . . . . . . . 14 6. Other Documents . . . . . . . . . . . . . . . . . . . . . . . 18 6.1. TIPHON: ETSI TS 101 321 . . . . . . . . . . . . . . . . . . 18 6.2. MSIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7. Accounting File and Record Formats . . . . . . . . . . . . . . 19 7.1. ASN.1 Records . . . . . . . . . . . . . . . . . . . . . . . 19 7.1.1. RTFM and AToMMIB . . . . . . . . . . . . . . . . . . . . . 19 7.1.2. Q.825 . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.2. Binary Records . . . . . . . . . . . . . . . . . . . . . . . 20 7.2.1. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.2.2. DIAMETER . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.3. Text Records . . . . . . . . . . . . . . . . . . . . . . . . 21 7.3.1. ROAMOPS . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. AAA Requirements . . . . . . . . . . . . . . . . . . . . . . . 22 8.1. A Well-defined Set of Attributes . . . . . . . . . . . . . . 22 8.2. A Simple Interchange Format . . . . . . . . . . . . . . . . 23 9. Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.1. Record Format vs. Protocol . . . . . . . . . . . . . . . . . 24 9.2. Tagged, Typed Data . . . . . . . . . . . . . . . . . . . . . 24 9.2.1. Standard Type Definitions . . . . . . . . . . . . . . . . 25 9.3. Transaction Identifiers . . . . . . . . . . . . . . . . . . 26 9.4. Service Definitions . . . . . . . . . . . . . . . . . . . . 26 9.4.1. Service Independence . . . . . . . . . . . . . . . . . . . 27 9.4.2. Versioned Service Definitions . . . . . . . . . . . . . . 29 9.4.3. Relationships Among Usage Events . . . . . . . . . . . . . 29 9.4.4. Service Namespace Management . . . . . . . . . . . . . . . 30 10. Encodings . . . . . . . . . . . . . . . . . . . . . . . . . . 30 11. Security Considerations . . . . . . . . . . . . . . . . . . . 31 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 31 13. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 35 14. Full Copyright Statement . . . . . . . . . . . . . . . . . . 36
1. Introduction
This document summarises IETF and ITU-T documents related to Accounting. For those documents which describe Accounting Attributes (i.e. quantities which can be measured and reported), an Attribute Summary is given. Although several of the documents describe Attributes which are similar, no attempt is made to identify those which are the same in several documents. An extensible classification scheme for AAA Accounting Attributes is proposed; it is a superset of the attributes in all the documents summarised.
Many existing accounting record formats and protocols [RAD-ACT] [TIPHON] are of limited use due to their single-service descriptive facilities and lack of extensibility. While some record formats and protocols support extensible attributes [RAD-ACT], none provide identification, type checking, or versioning support for defined groupings of attributes (service definitions). This document makes a case for well-defined services.
Advantages and disadvantages of integrated versus separate record formats and transport protocols are discussed. This document discusses service definition independence, extensibility, and versioning. Compound service definition capabilities are described.
2. Terminology and Notation
The following terms are used throughout the document.
Accounting Server
A network element that accepts Usage Events from Service Elements. It acts as an interface to back-end rating, billing, and operations support systems.
Attribute-Value Pair (AVP)
A representation for a Usage Attribute consisting of the name of the Attribute and a value.
A component of a Usage Event. A Usage Event describing a phone call, for instance, might have a "duration" Property.
A type of task that is performed by a Service Element for a Service Consumer.
Service Consumer
Client of a Service Element. End-user of a network service.
Service Definition
A specification for a particular service. It is composed of a name or other identifier, versioning information, and a collection of Properties.
Service Element
A network element that provides a service to Service Consumers. Examples include RAS devices, voice and fax gateways, conference bridges.
Usage Attribute
A component of a Usage Event that describes some metric of service usage.
Usage Event
The description of an instance of service usage.
3. Architecture Model
Service Elements provide Services to Service Consumers. Before, while, and/or after services are provided, the Service Element reports Usage Events to an Accounting Server. Alternately, the Accounting Server may query the Service Element for Usage Events. Usage events are sent singly or in bulk.
+------------+ +-----------+ +------------+ | Service |<----->| Service | Usage Events | Accounting | | Consumer | +-->| Element |------------->| Server | +------------+ | +-----------+ +------------+ | +------------+ | | Service |<--+ | Consumer | +------------+
Accounting Servers may forward Usage Events to other systems, possibly in other administrative domains. These transfers are not addressed by this document.
4. IETF Documents
In March 1999 there were at least 19 Internet Drafts and 8 RFCs concerned with Accounting. These are summarised (by working group) in the following sections.
The RADIUS protocol [RAD-PROT] carries authentication, authorization and configuration information between a Network Access Server (NAS) and an authentication server. Requests and responses carried by the protocol are expressed in terms of RADIUS attributes such as User- Name, Service-Type, and so on. These attributes provide the information needed by a RADIUS server to authenticate users and to establish authorized network service for them.
The protocol was extended to carry accounting information between a NAS and a shared accounting server. This was achieved by defining a set of RADIUS accounting attributes [RAD-ACT].
RADIUS packets have a short header containing the RADIUS packet type and authenticator (sixteen octets) and length, followed by a sequence of (Type, Length, Value) triples, one for each attribute.
RADIUS is very widely used, and a number of significant new extensions to it have been proposed. For example [RAD-EXT] discusses extensions to implement the Extensible Authentication Protocol (EAP) and the Apple Remote Access Protocol (ARAP). [RAD-TACC] discusses extensions to permit RADIUS to interwork effectively with tunnels using protocols such as PPTP and L2TP.
4.1.1. RADIUS Attributes
Each RADIUS attribute is identified by an 8-bit number, referred to as the RADIUS Type field. Up-to-date values of this field are specified in the most recent Assigned Numbers RFC [ASG-NBR], but the current list is as follows:
RADIUS Attributes [RAD-PROT] 36 Login-LAT-Group 37 Framed-AppleTalk-Link 1 User-Name 38 Framed-AppleTalk-Network 2 User-Password 39 Framed-AppleTalk-Zone 3 CHAP-Password 4 NAS-IP-Address 60 CHAP-Challenge 5 NAS-Port 61 NAS-Port-Type 6 Service-Type 62 Port-Limit 7 Framed-Protocol 63 Login-LAT-Port 8 Framed-IP-Address 9 Framed-IP-Netmask RADIUS Accounting Attributes 10 Framed-Routing [RAD-ACT] 11 Filter-Id 12 Framed-MTU 40 Acct-Status-Type 13 Framed-Compression 41 Acct-Delay-Time 14 Login-IP-Host 42 Acct-Input-Octets 15 Login-Service 43 Acct-Output-Octets 16 Login-TCP-Port 44 Acct-Session-Id 17 (unassigned) 45 Acct-Authentic 18 Reply-Message 46 Acct-Session-Time 19 Callback-Number 47 Acct-Input-Packets 20 Callback-Id 48 Acct-Output-Packets 21 (unassigned) 49 Acct-Terminate-Cause 22 Framed-Route 50 Acct-Multi-Session-Id 23 Framed-IPX-Network 51 Acct-Link-Count 24 State 25 Class RADIUS Extension Attributes 26 Vendor-Specific [RAD-EXT] 27 Session-Timeout 28 Idle-Timeout 52 Acct-Input-Gigawords 29 Termination-Action 53 Acct-Output-Gigawords 30 Called-Station-Id 54 Unused 31 Calling-Station-Id 55 Event-Timestamp 32 NAS-Identifier 33 Proxy-State 70 ARAP-Password 34 Login-LAT-Service 71 ARAP-Features 35 Login-LAT-Node 72 ARAP-Zone-Access 73 ARAP-Security 74 ARAP-Security-Data 75 Password-Retry 76 Prompt 77 Connect-Info 78 Configuration-Token 79 EAP-Message 80 Message-Authenticator 84 ARAP-Challenge-Response 85 Acct-Interim-Interval 87 NAS-Port-Id 88 Framed-Pool
RADIUS Tunneling Attributes
[RAD-TACC]64 Tunnel-Type 65 Tunnel-Medium-Type 66 Tunnel-Client-Endpoint 67 Tunnel-Server-Endpoint 68 Acct-Tunnel-Connection 69 Tunnel-Password 81 Tunnel-Private-Group-ID 82 Tunnel-Assignment-ID 83 Tunnel-Preference 90 Tunnel-Client-Auth-ID 91 Tunnel-Server-Auth-ID
The DIAMETER framework [DIAM-FRAM] defines a policy protocol used by clients to perform Policy, AAA and Resource Control. This allows a single server to handle policies for many services. The DIAMETER protocol consists of a header followed by objects. Each object is encapsulated in a header known as an Attribute-Value Pair (AVP).
DIAMETER defines a base protocol that specifies the header formats, security extensions and requirements as well as a small number of mandatory commands and AVPs. A new service can extend DIAMETER by extending the base protocol to support new functionality.
One key differentiator with DIAMETER is its inherent support for Inter-Server communication. Although this can be achieved in a variety of ways, the most useful feature is the ability to "proxy" messages across a set of DIAMETER servers (known as a proxy chain).
The DIAMETER Accounting Extension document [DIAM-ACT] extends DIAMETER by defining a protocol for securely transferring accounting records over the DIAMETER base protocol. This includes the case where accounting records may be passed through one or more intermediate proxies, in accordance with the 'referral broker' model.
The DIAMETER accounting protocol [DIAM-ACT] defines DIAMETER records for transferring an ADIF record (see below). It introduces five new attributes (480..485) which specify the way in which accounting information is to be delivered between DIAMETER servers.
4.2.1. DIAMETER Attributes
DIAMETER AVPs are identified by a 16-bit number defined in [DIAM- AUTH]. Since most of the AVPs found in that document were copied from the RADIUS protocol [RAD-PROT], it is possible to have both RADIUS and DIAMETER servers read the same dictionary and users files.
The backward compatibility that DIAMETER offers is intended to facilitate deployment. To this end, DIAMETER inherits the RADIUS attributes, and adds only a few of its own.
In the list below attribute numbers which are used for RADIUS attributes but not for DIAMETER are indicated with a star (*). RADIUS attributes used by DIAMETER are not listed again here.
The DIAMETER attributes are:
4 (unassigned, *) 17 (unassigned) 21 (unassigned) 24 (unassigned, *) 25 (unassigned, *) 27 (unassigned, *) 32 (unassigned, *) 33 (unassigned, *) 280 Filter-Rule 281 Framed-Password-Policy 480 Accounting-Record-Type 481 ADIF-Record 482 Accounting-Interim-Interval 483 Accounting-Delivery-Max-Batch 484 Accounting-Delivery-Max-Delay 485 Accounting-Record-Number 600 SIP-Sequence 601 SIP-Call-ID 602 SIP-To 603 SIP-From
[ROAM-IMPL] reviews the design and functionality of existing roaming implementations. "Roaming capability" may be loosely defined as the ability to use any one of multiple Internet service providers (ISPs), while maintaining a formal customer-vendor relationship with only one. One requirement for successful roaming is the provision of effective accounting.
[ROAM-ADIF] proposes a standard accounting record format, the Accounting Data Interchange Format (ADIF), which is designed to compactly represent accounting data in a protocol-independent manner. As a result, ADIF may be used to represent accounting data from any protocol using attribute value pairs (AVPs) or variable bindings.
ADIF does not define accounting attributes of its own. Instead, it gives examples of accounting records using the RADIUS accounting attributes.
The RTFM Architecture [RTFM-ARC] provides a general method of measuring network traffic flows between "metered traffic groups". Each RTFM flow has a set of "address" attributes, which define the traffic groups at each of the flow's end-points.
As well as address attributes, each flow has traffic-related attributes, e.g. times of first and last packets, counts for packets and bytes in each direction.
RTFM flow measurements are made by RTFM meters [RTFM-MIB] and collected by RTFM meter readers using SNMP. The MIB uses a "DataPackage" convention, which specifies the attribute values to be read from a flow table row. The meter returns the values for each required attribute within a BER-encoded sequence. This means there is only one object identifier for the whole sequence, greatly reducing the number of bytes required to retrieve the data.
4.4.1. RTFM Attributes
RTFM attributes are identified by a 16-bit attribute number.
The RTFM Attributes are:
0 Null 1 Flow Subscript Integer Flow table info 4 Source Interface Integer Source Address 5 Source Adjacent Type Integer 6 Source Adjacent Address String 7 Source Adjacent Mask String 8 Source Peer Type Integer 9 Source Peer Address String 10 Source Peer Mask String 11 Source Trans Type Integer 12 Source Trans Address String 13 Source Trans Mask String 14 Destination Interface Integer Destination Address 15 Destination Adjacent Type Integer 16 Destination Adjacent Address String 17 Destination AdjacentMask String 18 Destination PeerType Integer 19 Destination PeerAddress String 20 Destination PeerMask String 21 Destination TransType Integer 22 Destination TransAddress String 23 Destination TransMask String 26 Rule Set Number Integer Meter attribute 27 Forward Bytes Integer Source-to-Dest counters 28 Forward Packets Integer 29 Reverse Bytes Integer Dest-to-Source counters 30 Reverse Packets Integer 31 First Time Timestamp Activity times 32 Last Active Time Timestamp 33 Source Subscriber ID String Session attributes 34 Destination Subscriber ID String 35 Session ID String 36 Source Class Integer "Computed" attributes 37 Destination Class Integer 38 Flow Class Integer 39 Source Kind Integer 40 Destination Kind Integer 41 Flow Kind Integer 50 MatchingStoD Integer PME variable 51 v1 Integer Meter Variables 52 v2 Integer 53 v3 Integer 54 v4 Integer 55 v5 Integer
65-127 "Extended" attributes
(to be defined by the RTFM working group)
The ISDN MIB [ISDN-MIB] defines a minimal set of managed objects for SNMP-based management of ISDN terminal interfaces. It does not explicitly define anything related to accounting, however it does define isdnBearerChargedUnits as
The number of charged units for the current or last connection. For incoming calls or if charging information is not supplied by the switch, the value of this object is zero.
This allows for an ISDN switch to convert its traffic flow data (such as Call Connect Time) into charging data.
4.5.1. ISDN Attributes
The relevant object in the MIB is the ISDN bearer table, which has entries in the following form:
IsdnBearerEntry ::=
isdnBearerChannelType INTEGER, isdnBearerOperStatus INTEGER, isdnBearerChannelNumber INTEGER, isdnBearerPeerAddress DisplayString, isdnBearerPeerSubAddress DisplayString, isdnBearerCallOrigin INTEGER, isdnBearerInfoType INTEGER, isdnBearerMultirate TruthValue, isdnBearerCallSetupTime TimeStamp, isdnBearerCallConnectTime TimeStamp, isdnBearerChargedUnits Gauge32 }
4.6. AToMMIB
The "ATM Accounting Information MIB" document [ATM-ACT] describes a large set of accounting objects for ATM connections. An administrator may select objects from this set using a selector of the form (subtree, list) where "subtree" specifies an object identifier from the AToMMIB. For each subtree there is a table holding values for each ATM connection. The required connections are indicated by setting bits in "list", which is an octet string. For example, the set containing the number of received cells for the first eight ATM connections would be selected by (atmAcctngReceivedCells, 0xFF).
The Connection-Oriented Accounting MIB document [ATM-COLL] defines a MIB providing managed objects used for controlling the collection and storage of accounting information for connection-oriented networks such as ATM. The accounting data is collected into files for later retrieval via a file transfer protocol. Records within an accounting file are stored as BER strings [ASN1, BER].
4.6.1. AToMMIB Attributes
Accounting data objects within the AToMMBIB are identified by the last integer in their object identifiers.
The ATM accounting data objects are:
1 atmAcctngConnectionType 2 atmAcctngCastType 3 atmAcctngIfName 4 atmAcctngIfAlias 5 atmAcctngVpi 6 atmAcctngVci 7 atmAcctngCallingParty 8 atmAcctngCalledParty 9 atmAcctngCallReference 10 atmAcctngStartTime 11 atmAcctngCollectionTime 12 atmAcctngCollectMode 13 atmAcctngReleaseCause 14 atmAcctngServiceCategory 15 atmAcctngTransmittedCells 16 atmAcctngTransmittedClp0Cells 17 atmAcctngReceivedCells 18 atmAcctngReceivedClp0Cells 19 atmAcctngTransmitTrafficDescriptorType 20 atmAcctngTransmitTrafficDescriptorParam1 21 atmAcctngTransmitTrafficDescriptorParam2 22 atmAcctngTransmitTrafficDescriptorParam3 23 atmAcctngTransmitTrafficDescriptorParam4 24 atmAcctngTransmitTrafficDescriptorParam5 25 atmAcctngReceiveTrafficDescriptorType 26 atmAcctngReceiveTrafficDescriptorParam1 27 atmAcctngReceiveTrafficDescriptorParam2 28 atmAcctngReceiveTrafficDescriptorParam3 29 atmAcctngReceiveTrafficDescriptorParam4 30 atmAcctngReceiveTrafficDescriptorParam5 31 atmAcctngCallingPartySubAddress 32 atmAcctngCalledPartySubAddress 33 atmAcctngRecordCrc16
4.7. QoS: RSVP and DIFFSERV
As we move towards providing more than simple "best effort" connectivity, there has been a tremendous surge of interest in (and work on) protocols to provide managed Quality of Service for Internet sessions. This is of particular interest for the provision of "Integrated Services", i.e. the transport of audio, video, real-time, and classical data traffic within a single network infrastructure.
Two approaches to this have emerged so far:
- the Integrated Services architecture (intserv) [IIS-ARC], with its accompanying signaling protocol, RSVP [RSVP-ARC], and RSVP's Common Open Policy Service protocol, COPS [RAP-COPS] - the Differentiated Services architecture (diffserv) [DSRV-ARC]
RSVP is a signaling protocol that applications may use to request resources from the network. The network responds by explicitly admitting or rejecting RSVP requests. Certain applications that have quantifiable resource requirements express these requirements using intserv parameters [IIS-SPEC].
Diffserv networks classify packets into one of a small number of aggregated flows or "classes", based on the diffserv codepoint (DSCP) in the packet's IP header. At each diffserv router, packets are subjected to a "per-hop behavior" (PHB), which is invoked by the DSCP. Since RSVP is purely a requirements signalling protocol it can also be used to request connections from a diffserv network [RS-DS- OP].
4.7.1. RSVP and DIFFSERV Attributes
A set of parameters for specifying a requested Quality of Service are given in [IIS-SPEC]. These have been turned into accounting attributes within RTFM [RTFM-NEWA] and within the RSVP MIB [RSVP- MIB].
The RTFM QoS attributes are:
98 QoSService 99 QoSStyle 100 QoSRate 101 QoSSlackTerm 102 QoSTokenBucketRate 103 QoSTokenBucketSize 104 QoSPeakDataRate 105 QoSMinPolicedUnit 106 QoSMaxPolicedUnit
The RSVP MIB contains a large number of objects, arranged within the following sections:
General Objects
Session Statistics Table
Session Sender Table
Reservation Requests Received Table
Reservation Requests Forwarded Table
RSVP Interface Attributes Table
RSVP Neighbor Table
The Session tables contain information such as the numbers of senders and receivers for each session, while the Reservation Requests tables contain details of requests handled by the RSVP router. There are too many objects to list here, but many of them could be used for accounting. In particular, RSVP Requests contain the specification of the service parameters requested by a user; these, together with the actual usage data for the connection make up an accounting record for that usage.
5. ITU-T Documents
5.1. Q.825: Call Detail Recording
ITU-T Recommendation Q.825 specifies how CDRs (Call Detail Records) are produced and managed in Network Elements for POTS, ISDN and IN (Intelligent Networks).
Uses of Call Detail information for various purposes are discussed.
Each call produces one or more records describing events that occurred during the life of a call. Data may be produced in real time (single CDRs), near real-time (blocks of CDRs), or as batch files of CDRs.
The information model for Call Detail Recording is formally described in terms of an Entity-Relationship model, and an object model specified in terms of GDMO templates (Guidelines for the Definition of Managed Objects). Note that this model includes the ways in which CDRs are transported from the (NE) Network Element where they are generated to the OS (Operations System) where they are used.
5.2. Q.825 Attributes
The following attributes are defined. The explanations given are very brief summaries only, see [Q-825] for the complete text.
1 accessDelivery Indicates that the call was delivered to the called subscriber 2 accountCodeInput Account code (for billing), supplied by subscriber. 78 additionalParticipantInfo (No details given) 5 b-PartyCategory Subscriber category for called subscriber. 4 bearerService Bearer capability information (only for ISDN calls). 13 cDRPurpose Reason for triggering this Call Data Record. 70 callDetailDataId Unique identifier for the CallDetailData object. 79 callDuration Duration of call 6 callIdentificationNumber Identification number for call; all records produced for this call have the same callIdenfificationNumber. 73 callStatus Identifies whether the call was answered or not. 9 calledPartyNumber Telephone number of the called subscriber (may be a "diverted-to" or "translated" number. 7 callingPartyCategory Calling subscriber category. 8 callingPartyNumber Telephone number of the calling party. 10 callingPartyNumberNotScreened An additional, user-provided (not screened) number to the calling party. 11 callingPartyType Calling subscriber type. 74 carrierId Carrier ID to which the call is sent. 12 cause Cause and location value for the termination of the call. 14 chargedDirectoryNumber Charged directory number (where the charged participant element can't indicate the number). 16 chargedParticipant Participant to be charged for the usage. 15 chargingInformation Charging information generated by a Network Element which is capable of charging. 17 configurationMask Time consumption, e.g. from B-answer to termination time, between partial call records, etc. 18 conversationTime Time consumption from B-answer to end of call. 19 creationTriggerList List of trigger values which will create Call Detail data objects. 75 dPC Destination point code (for analysis purposes). 20 dataValidity Indicates that the NE is having problems, contents of the generated Call Detail record is not reliable. 23 durationTimeACM Time consumption from seizure until received ACM. 21 durationTimeB-Answer Time consumption from seizure until B-answer. 22 durationTimeNoB-Answer Time from seizure to termination when no B-answer was received. 25 exchangeInfo Identity of exchange where Call Detail record was generated. 26 fallbackBearerService Fallback bearer capability information for a call. 27 glare Indicates if a glare condition was encountered. 31 iNServiceInformationList Contains information about the use of IN (Intelligent Network) services. 32 iNSpecificInformation Contains information about the use of one IN service. 33 iSUPPreferred Indicate whether an ISUP preference was requested. 28 immediateNotificationForUsageMetering Indicates that the Call Detail records requires immediate data transfer to the Operations System. 34 maxBlockSize Maximum number of Call Detail records in a block. 35 maxTimeInterval Maximum latency allowable for near-real-time Call Detail data delivery. 36 networkManagementControls Indicates which Traffic Management Control has affected the call. 37 networkProviderId Indicates the Network Provider for whom the CDR is generated. 76 oPC Originating point code for a failed call (for analysis purposes). 38 operatorSpecific1AdditionalNumber 40 operatorSpecific2AdditionalNumber 42 operatorSpecific3AdditionalNumber Operator-defined additional participant information. 39 operatorSpecific1Number 41 operatorSpecific2Number 43 operatorSpecific3Number Operator-defined participant information. 44 originalCalledNumber Telephone number of the original called party. 45 partialGeneration Included if the CDR (Call Detail record) output is partial. Such CDRs have a field indicating their partial record number. 77 participantInfo (No details given). 46 percentageToBeBilled Percentage to be billed when normal billing rules are not to be followed. 47 periodicTrigger Defines the intervals at which the CDR file should be created. 48 personalUserId Internationally unique personal User Identity (for UPT calls). 49 physicalLineCode Identifies the call subscriber's physical line. 50 progress Describes an event which occurred during the life of a call. 51 queueInfo Used to record usage of queueing resources with IN calls. 52 receivedDigits The digits dialed by the subscriber. (Normally only included for customer care purposes). 53 recordExtensions Information elements added by network operators and/or manufacturers in addition to the standard ones above.
6. Other Documents
TIPHON [TIPHON] is an XML-based protocol, carried by HTTP, which handles accounting and authorization requests and responses.
The following are elements selected from TIPHON's DTD that are used for accounting.
<!ELEMENT Currency (#PCDATA)> <!ELEMENT Amount (#PCDATA)>
Identifies a numeric value. Expressed using the period (.) as a decimal separator with no punctuation as the thousands separator.
<!ELEMENT CallId (#PCDATA)>
Contains a call's H.323 CallID value, and is thus used to uniquely identify individual calls.
<!ELEMENT Currency (#PCDATA)>
Defines the financial currency in use for the parent element.
<!ELEMENT DestinationInfo type ( e164 | h323 | url | email |
transport | international | national | network | subscriber | abbreviated | e164prefix ) Gives the primary identification of the destination for a call.
<!ELEMENT Increment (#PCDATA)>
Indicates the number of units being accounted.
<!ELEMENT Service EMPTY>
Indicates a type of service being priced, authorized, or reported. An empty Service element indicates basic Internet telephony service, which is the only service type defined by V1.4.2 of the specification. The specification notes that "Later revisions of this standard are expected to specify more enhanced service definitions to represent quality of service, availability, payment methods, etc."
<!ELEMENT DestinationInfo type ( e164 | h323 | url | email |
transport | international | national | network | subscriber | abbreviated | e164prefix) Gives the primary identification of the source of a call.
<!ELEMENT Timestamp (#PCDATA)>
A restricted form of [ISO-DATE] that indicates the time at which the component was generated.
<!ELEMENT TransactionId (#PCDATA)>
Contains an integer, decimal valued identifier assigned to a specific authorized transaction.
<!ELEMENT Unit (#PCDATA)>
Indicates the units by which pricing is measured or usage recorded. It shall contain one of the following values:
s seconds p packets (datagrams) byte bytes <!Element UsageDetail ( Service, Amount, Increment, Unit ) > Collects information describing the usage of a service.
MSIX [MSIX-SPEC] is an XML-based protocol transported by HTTP that is used to make accounting service definitions and transmit service usage information. As its service definitions are parameterized and dynamic, it makes no definition of services or attributes itself, but allows implementors to make their own. It specifies only the base data types that attributes may take: STRING, UNISTRING, INT32, FLOAT, DOUBLE, BOOLEAN, TIMESTAMP.
7. Accounting File and Record Formats
7.1. ASN.1 Records
7.1.1. RTFM and AToMMIB
RTFM and AToMMIB use ASN.1 Basic Encoding Rules (BER) to encode lists of attributes into accounting records. RTFM uses SNMP to retrieve such records as BER strings, thus avoiding having to have an object identifier for every object.
AToMMIB carries this a stage further by defining an accounting file format in ASN.1 and making it available for retrieval by a file transfer protocol, thereby providing a more efficient alternative to simply retrieving the records using SNMP.
A Q.825 Call Record is an ASN.1 SET containing a specified group of the Q.825 attributes. Call records would presumably be encoded as BER strings before being collected for later processing.
7.2. Binary Records
Radius packets carry a sequence of attributes and their values, as (Type, Length, Value) triples. The format of the value field is one of four data types.
string 0-253 octets address 32 bit value, most significant octet first. integer 32 bit value, most significant octet first. time 32 bit value, most significant octet first -- seconds since 00:00:00 GMT, January 1, 1970. The standard Attributes do not use this data type but it is presented here for possible use within Vendor-Specific attributes.
Each DIAMETER message consists of multiple AVP's that are 32-bit aligned, with the following format:
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AVP Code | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AVP Length | Reserved |P|T|V|R|M| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Vendor ID (opt) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tag (opt) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data ... +-+-+-+-+-+-+-+-+
The AVP Code identifies the attribute uniquely. If the Vendor- Specific bit is set, the AVP Code is allocated from the vendor's private address space.
The first 256 AVP numbers are reserved for backward compatibility with RADIUS and are to be interpreted as per RADIUS [RAD-PROT]. AVP numbers 256 and above are used for DIAMETER, which are allocated by IANA.
AVP Length
A 16-bit field contains the total object length in bytes. Must always be a multiple of 4, and at least 8.
AVP Flags
P Protected bit T Tag bit V Vendor-ID bit R Reserved (MUST be set to 0) M Mandatory bit
7.3. Text Records
ADIF (Accounting Data Interchange Format [ROAM-ADIF]) presents a general, text-based format for accounting data files, described in a straightforward BNF grammar. Its file header contains a field indicating the default protocol from which accounting attributes are drawn. If an attribute from another protocol is to be used, it is preceded by its protocol name, for example rtfm//27 would be RTFM's "forward bytes" attribute. Comments in an ADIF file begin with a cross-hatch.
An ADIF file encoding RADIUS accounting data
version: 1 device: server3 description: Accounting Server 3 date: 02 Mar 1999 12:19:01 -0500 defaultProtocol: radius rdate: 02 Mar 1999 12:20:17 -0500 #NAS-IP-Address 4: 188.8.131.52 #NAS-Port 5: 12 #NAS-Port-Type 61: 2 #User-Name 1: firstname.lastname@example.com #Acct-Status-Type 40: 2 #Acct-Delay-Time 41: 14 #Acct-Input-Octets 42: 234732 #Acct-Output-Octets 43: 15439 #Acct-Session-Id 44: 185 #Acct-Authentic 45: 1 #Acct-Session-Time 46: 1238 #Acct-Input-Packets 47: 153 #Acct-Output-Packets 48: 148 #Acct-Terminate-Cause 49: 11 #Acct-Multi-Session-Id 50: 73 #Acct-Link-Count 51: 2
8. AAA Requirements
8.1. A Well-Defined Set of Attributes
AAA needs a well-defined set of attributes whose values are to be carried in records to or from accounting servers.
Most of the existing sets of documents described above include a set of attributes, identified by small integers. It is likely that these sets overlap, i.e. that some of them have attributes which represent the same quantity using different names in different sets. This suggests it might be possible to produce a single combined set of "universal" accounting attributes, but such a "universal" set does not seem worthwhile.
The ADIF approach of specifying a default protocol (from which attributes are assumed to come) and identifying any exceptions seems much more practical. We therefore propose that AAA should use the
ADIF convention (or something like it) to identify attributes, together with all the sets of attributes covered by the [ASG-NBR] document.
8.2. A Simple Interchange Format
AAA needs a simple interchange file format, to be used for accounting data. Several schemes for packaging and transporting such data have been described above.
The SNMP-based ones fit well within the context of an SNMP-based network management system. RTFM and AToMMIB provide ways to reduce the SNMP overhead for collecting data, and AToMMIB defines a complete file format. Both provide good ways to collect accounting data.
As an interchange format, however, ASN.1-based schemes suffer from being rather complex binary structures. This means that one requires suitable tools to work with them, as compared to plain-text files where one can use existing text-based utilities.
The binary schemes such as RADIUS and DIAMETER have simpler structures, but they too need purpose-built tools. For general use they would need to be extended to allow them to use attributes from other protocols.
From the point of view of being easy for humans to understand, ADIF seems very promising. Of course any processing program would need a suitable ADIF input parser, but using plain-text files makes them much easier to understand.
TIPHON's record format is specified by an XML DTD. While XML representations have the advantages of being well-known, they are limited by XML's inability to specify type or other validity checking for information within the tags. This situation will likely be improved by the XML Schema [XML-SCHM] efforts that are underway, but a stable reference is not yet available.
9. Issues
It is generally agreed that there is a need for a standard record format and transport protocol for communication between Service Elements and Accounting Servers.
There is less agreement on the following issues:
o Separate or integral record format and transport protocol o Standard set of base data types
o Service definitions: part of the protocol or separately defined- Service definition namespace management
The following sections address these issues.
9.1. Record Format vs. Protocol
All known Internet-centric billing protocols to date have an integral record format. That is, the collection of Properties that describe a Usage Event are specified as an integral part of the protocol, typically as a part of a "submit" message that is used to transmit a Usage Event from a Service Entity to an Accounting Server.
It may be advantageous to define a record format that is independent of the transport protocol. Such a record format should support both representation of individual records and records in bulk, as Usage Events are often aggregated and transmitted in bulk.
A separate record format is useful for record archiving and temporary file storage. Multiple transport protocols may be defined without affecting the record format. The task of auditing is made easier if a standard file format is defined. If a canonical format is used, bulk records may be hashed with MD5 [MD5] or a similar function, for reliability and security purposes.
+------------+ | transport | | header | +------------+ +------------+ | | | | | Usage | | Usage | | Event(s) | | Event(s) | | | | | | | | | +------------+ +------------+ | trailer | +------------+ record format transport protocol
If the protocol is written such that it can transmit Usage Events in the record format, no record rewriting for transport is required.
9.2. Tagged, Typed Data
Record formats and protocols use a combination of data locality and explicit tagging to identify data elements. Mail [RFC822], for instance, defines a header block composed of several Attribute-Value Pairs, followed by a message body. Each header field is explicitly tagged, but the order of the AVPs is undefined. The message body is not tagged (except with an additional preceding blank line), and is found through its position in the message, which must be after all header fields.
Some record formats make no use of tags--data elements are identified only by their position within a record structure. While this practice provides for the least amount of record space overhead, it is difficult to later modify the record format by adding or removing elements, as all record readers will have to be altered to handle the change. Tagged data allows old readers to detect unexpected tags and to detect if required data are missing. If the overhead of carrying explicit tags can be borne, it is advantageous to use explicitly tagged data elements where possible.
An AVP approach has proven useful in accounting. RADIUS [RADIUS] uses numeric data type identifiers. ETSI's TIPHON [TIPHON] uses XML markup.
For an AAA accounting record format, the authors suggest that each Property be named by a textual or numeric identifier and carry a value and a data type indicator, which governs interpretation of the value. It may also be useful for each Property to carry a units of measure identifier. The TIPHON specification takes this approach. TS 101 321 also carries an Increment field, which denominates the Property's Unit of Measure field. Whether this additional convenience is necessary is a matter for discussion.
It is not strictly necessary for each data record to carry data type, units of measure, or increments identifiers. If this information is recorded in a record schema document that is referenced by each data record, each record may be validated against the schema without the overhead of carrying type information.
9.2.1. Standard Type Definitions
It is useful to define a standard set of primitive data types to be used by the record format and protocol. Looking at the prior art, DIAMETER supports Data (arbitrary octets), String (UTF-8), Address (32 or 128 bit), Integer32, Integer64, Time (32 bits, seconds since 1970), and Complex. MSIX [MSIX-SPEC] supports String, Unistring, Int32, Float, Double, Boolean, and Timestamp. SMIv2 [SMI-V2] offers ASN.1 types INTEGER, OCTET STRING, and OBJECT IDENTIFIER, and the application-defined types Integer32, IpAddress, Counter32, Gauge32, Unsigned32, TimeTicks, Opaque, and Counter64.
An appropriate set would likely include booleans, 32 and 64 bit signed integers, 32 and 64 bit floats, arbitrary octets, UTF-8 and UTF-16 strings, and ISO 8601:1988 [ISO-DATE] timestamps. Fixed- precision numbers capable of representing currency amounts (with precision specified on both sides of the decimal point) have proven useful in accounting record formats, as they are immune to the precision problems that are encountered when one attempts to represent fixed-point amounts with floating point numbers.
It may be worthwhile to consider the datatypes that are being specified by the W3C's "XML Schema Part 2: Datatypes" [XML-DATA] document. That document specifies a rich set of base types, along with a mechanism to specify derivations that further constrain the base types.
9.3. Transaction Identifiers
Each Usage Event requires its own unique identifier.
It is expedient to allow Service Elements to create their own unique identifiers. In this manner, Usage Events can be created and archived without the involvement of an Accounting Server or other central authority.
A number of methods for creating unique identifiers are well known. One popular identifier is an amalgamation of a monotonically increasing sequence number, a large random value, a network element identifier, and a timestamp. Another possible source of entropy is a hash value of all or part of the record itself.
RFC 822 [MAIL], RFC 1036 [NEWS], and RFC 2445 [ICAL-CORE] give guidance on the creation of good unique identifiers.
9.4. Service Definitions
A critical differentiator in accounting record formats and protocols is their capability to account for arbitrary service usage. To date, no accounting record format or protocol that can handle arbitrary service definitions has achieved broad acceptance on the Internet.
This section analyzes the issues in service definition and makes a case for a record format and protocol with the capability to carry Usage Events for rich, independently-defined services.
9.4.1. Service Independence
It is informative to survey a number of popular Internet protocols and document encodings and examine their capacities for extension. These protocols can be categorized into two broad categories--"fully specified" protocols that have little provision for extension and "framework" protocols that are incomplete, but provide a basis for future extension when coupled with application documents.
Examples of fully-specified protocols are NTP [NTP], NNTP [NNTP], RADIUS Accounting [RAD-ACT], and HTML [HTML].
Aside from leaving some field values "reserved for future use", all of Network Time Protocol's fields are fixed-width and completely defined. This is appropriate for a simple protocol that solves a simple problem.
Network News Transfer Protocol [NEWS-PROT] specifies that further commands may be added, and requests that non-standard implementations use the "X-" experimental prefix so as to not conflict with future additions. The content of news is 7-bit data, with the high-order bit cleared to 0. Nothing further about the content is defined. There is no in-protocol facility for automating decoding of content type.
We pay particular attention to RADIUS Accounting [RAD-ACT]. Perhaps the second most frequently heard complaint (after security shortcomings) about RADIUS Accounting is its preassigned and fixed set of "Types". These are coded as a range of octets from 40 to 51 and are as follows:
40 Acct-Status-Type 41 Acct-Delay-Time 42 Acct-Input-Octets 43 Acct-Output-Octets 44 Acct-Session-Id 45 Acct-Authentic 46 Acct-Session-Time 47 Acct-Input-Packets 48 Acct-Output-Packets 49 Acct-Terminate-Cause 50 Acct-Multi-Session-Id 51 Acct-Link-Count
These identifiers were designed to account for packet-based network access service. They are ill-suited for describing other services. While extension documents have specified additional types, the base protocol limits the type identifier to a single octet, limiting the total number of types to 256.
HTML/2.0 [HTML] is mostly a fully-specified protocol, but with W3C's HTML/4.0, HTML is becoming more of a framework protocol. HTML/2.0 specified a fixed set of markups, with no provision for addition (without protocol revision).
Examples of "framework" protocols and document encodings are HTTP, XML, and SNMP.
HTTP/1.1 [HTTP] is somewhat similar to NNTP in that it is designed to transport arbitrary content. It is different in that it supports description of that content through its Content-Type, Content- Encoding, Accept-Encoding, and Transfer-Encoding header fields. New types of content can be designated and carried by HTTP/1.1 without modification to the HTTP protocol.
XML [XML] is a preeminent general-purpose framework encoding. DTD publishing is left to users. There is no standard registry of DTDs.
SNMP presents a successful example of a framework protocol. SNMP's authors envisioned SNMP as a general management protocol, and allow extension through the use of private MIBs. SNMP's ASN.1 MIBs are defined, published, and standardized without the necessity to modify the SNMP standard itself. From "An Overview of SNMP" [SNMP-OVER]:
It can easily be argued that SNMP has become prominent mainly from its ability to augment the standard set of MIB objects with new values specific for certain applications and devices. Hence, new functionality can continuously be added to SNMP, since a standard method has been defined to incorporate that functionality into SNMP devices and network managers.
Most accounting protocols are fully-specified, with either a completely defined service or set of services (RADIUS Accounting) or with one or more services defined and provision for "extension" services to be added to the protocol later (TIPHON). While the latter is preferable, it may be preferable to take a more SNMP-like approach, where the accounting record format and protocol provide only a framework for service definition, and leave the task of service definition (and standardization) to separate efforts. In this manner, the accounting protocol itself would not have to be modified to handle new services.
9.4.2. Versioned Service Definitions
Versioning is a naming and compatibility issue. Version identifiers are useful in service definition because they enable service definitions to be upgraded without a possibly awkward name change. They also enable possible compatibility between different versions of the same service.
An example could be the service definition of a phone call. Version 1 might define Properties for the start time, duration, and called and calling party numbers. Later, version 2 is defined, which augments the former service definition with a byte count. An Accounting Server, aware only of Version 1, may accept Version 2 records, discarding the additional information (forward compatibility). Alternately, if an Accounting Server is made aware of version 2, it could optionally still accept version 1 records from Service Elements, provided the Accounting Sever does not require the additional information to properly account for service usage (backward compatibility).
9.4.3. Relationships Among Usage Events
Accounting record formats and protocols to date do not sufficiently addressed "compound" service description.
A compound service is a service that is described as a composition of other services. A conference call, for example, may be described as a number of point-to-point calls to a conference bridge. It is important to account for the individual calls, rather than just summing up an aggregate, both for auditing purposes and to enable differential rating. If these calls are to be reported to the Accounting Server individually, the Usage Events require a shared identifier that can be used by the Accounting Server and other back- end systems to group the records together.
In order for a Service Element to report compound events over time as a succession of individual Usage Events, the accounting protocol requires a facility to communicate that the compound event has started and stopped. The "start" message can be implicit--the transmission of the first Usage Event will suffice. An additional semaphore is required to tell the Accounting Server that the compound service is complete and may be further processed. This is necessary to prevent the Accounting Server from prematurely processing compound events that overlap the end of a billing period.
RADIUS Accounting has some provision for this sort of accounting with its "Acct-Multi-Session-Id" field. Unfortunately, RADIUS Accounting's other shortcomings preclude it from being used in general purpose service usage description.
9.4.4. Service Namespace Management
"Framework" protocols, as previously mentioned, do not define complete schema for their payload. For interoperability to be achieved, it must be possible for:
(1) content definers to specify definitions without conflicting
with the names of other definitions
(2) protocol users to find and use content definitions
Condition (1) can be readily managed through IANA assignment or by using an existing namespace differentiator (for example, DNS).
Condition (2) is harder, and places considerable burden on the implementors. Their clients and servers must be able, statically or dynamically, to find and validate definitions, and manage versioning issues.
As previously mentioned, the XML specification provides no facility for DTD discovery or namespace management. XML specifies only a document format, and as such does not need to specify support for more "protocol" oriented problems.
For an accounting record format and protocol, an approach closer to SNMP's is useful. SNMP uses an ISO-managed dotted-decimal namespace. An IANA-managed registry of service types is a possibility. Another possibility, used by MSIX [MSIX-SPEC], is for Service Element creators to identify their services by concatenation of a new service name with existing unique identifier, such as a domain name.
A standard record format for service definitions would make it possible for Service Element creators to directly supply accounting system managers with the required definitions, via the network or other means.
10. Encodings
It may be useful to define more than one record encoding.
A "verbose" XML encoding is easily implemented and records can be syntactically verified with existing tools. "Human-readable" protocols tend to have an edge on "bitfield" protocols where ease of implementation is paramount and the application can tolerate any additional processing required to generate, parse, and transport the records.
A alternative "compressed" encoding that makes minimal use of storage and processing may be useful in many contexts.
There are disadvantages to supporting multiple encodings. Optionally-supported multiple encodings mandate the requirement for capabilities exchange between Service Element and Accounting Server. Also, implementations can tend to "drift apart", with one encoding better-supported than another. Unless all encodings are mandatory, implementors may find they are unable to interoperate because they picked the wrong encoding.
11. Security Considerations
This document summarises many existing IETF and ITU documents; please refer to the original documents for security considerations for their particular protocols.
It must be possible for the accounting protocol to be carried by a secure transport. A canonical record format is useful so that regeneration of secure record hashes is possible.
When dealing with accounting data files, one must take care that their integrity and privacy are preserved. This document, however, is only concerned with the format of such files.
12. References
[ACC-BKG] Mills, C., Hirsch, G. and G. Ruth, "Internet Accounting Background", RFC 1272, November 1991. [ASG-NBR] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2, RFC 1700, October 1994. [ASN1] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization, International Standard 8824, December 1987. [ATM-ACT] McCloghrie, K., Heinanen, J., Greene, W. and A. Prasad, "Accounting Information for ATM Networks", RFC 2512, February 1999. [ATM-COLL] McCloghrie, K., Heinanen, J., Greene, W. and A. Prasad, " Managed Objects for Controlling the Collection and Storage of Accounting Information for Connection-Oriented Networks", RFC 2513, February 1999. [BER] Information processing systems - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Notation One (ASN.1), International Organization for Standardization, International Standard 8825, December 1987. [DIAM-ACT] Arkko, J., Calhoun, P.R., Patel, P. and Zorn, G., "DIAMETER Accounting Extension", Work in Progress. [DIAM-AUTH] Calhoun, P.R. and Bulley, W., "DIAMETER User Authentication Extensions", Work in Progress. [DIAM-FRAM] Calhoun, P.R., Zorn, G. and Pan, P., "DIAMETER Framework Document", Work in Progress. [DSRV-ARC] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, December 1998. [HTML] Berners-Lee, T. and D. Connolly, "Hypertext Markup Language - 2.0", RFC 1866, November 1995. [HTTP] Fielding, R., Gettys, J., Mogul, J. Frystyk, H. and T. Berners-Lee, "Hypertext Transfer Protocol--HTTP/1.1", RFC 2068, January 1997. [ICAL-CORE] Dawson, F. and D. Stenerson, "Internet Calendaring and Scheduling Core Object Specification", RFC 2445, November 1998. [IIS-ARC] Braden, R., Clark, D. and S. Shenker, "Integrated Services in the Internet Architecture: an Overview", RFC 1633, June 1994. [IIS-SPEC] Shenker, S., Partridge, C. and R. Guerin, "Specification of Guaranteed Quality of Service", RFC 2212, September 1997. [ISDN-MIB] Roeck, G., "ISDN Management Information Base using SMIv2", RFC 2127, March 1997. [ISO-DATE] "Data elements and interchange formats -- Information interchange -- Representation of dates and times", ISO 8601:1988. [MAIL] Crocker, D., "STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES", STD 11, RFC 822, August 1982. [MD5] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, April 1992. [MSIX-SPEC] Blount, A. and D. Young, "Metered Service Information Exchange 1.2", Work in Progress. [NEWS-MSGS] Horton, M. and R. Adams, "Standard for Interchange of USENET Messages", RFC 1036, December 1987. [NEWS-PROT] Kantor, B. and P. Lapsley, "Network News Transfer Protocol", RFC 977, February 1986. [NTP] Mills, D., "Network Time Protocol (NTP)", RFC 958, September 1985. [Q-825] "Specification of TMN applications at the Q3 interface: Call detail recording", ITU-T Recommendation Q.825, 1998. [RAD-ACT] Rigney, C., "RADIUS Accounting", RFC 2866, June 2000. [RAD-EXT] Rigney, C., Willats, W. and Calhoun, P., "RADIUS Extensions", RFC 2869, June 2000. [RAD-PROT] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. [RAD-TACC] Zorn, G., Mitton, D. and A. Aboba, "RADIUS Accounting Modifications for Tunnel Protocol Support", RFC 2867, June 2000. [RAP-COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Rajan, R. and A. Sastry, "The COPS (Common Open Policy Service) Protocol", RFC 2748, January 2000. [ROAM-ADIF] Aboba, B. and D. Lidyard, "The Accounting Data Interchange Format (ADIF)", Work in Progress. [ROAM-IMPL] Aboba, B., Lu, J., Alsop, J., Ding, J. and W. Wang, "Review of Roaming Implementations", RFC 2194, September 1997. [RS-DS-OP] Bernet, Y., Yavatkar, R., Ford, P., Baker, F., Zhang, L., Speer, M., Braden, R., Davie, B., Wroclawski, J. and E. Felstaine, "A Framework For Integrated Services Operation Over Diffserv Networks", Work in Progress. [RSVP-ARC] Braden, R., Zhang, L., Berson, S., Herzog, S. and S. Jamin, "Resource Reservation Protocol (RSVP) Version 1 Functional Specification", RFC 2205, September 1997. [RSVP-MIB] Baker, F., Krawczyk, J. and A. Sastry, "RSVP Management Information Base using SMIv2", RFC 2206, September 1997. [RTFM-ARC] Brownlee, N., Mills, C. and G. Ruth, "Traffic Flow Measurement: Architecture", RFC 2722, October 1999. [RTFM-MIB] Brownlee, N., "Traffic Flow Measurement: Meter MIB", Measurement: Architecture", RFC 2720, October 1999. [RTFM-NEWA] Handelman, S., Brownlee, N., Ruth, G. and S. Stibler, "New Attributes for Traffic Flow Measurement", RFC 2724, October 1999. [SIP-PROT] Handley, M., Schulzrinne, H., Schooler, E. and J. Rosenberg, "SIP: Session Initiation Protocol", RFC 2543, March 1999. [SMI-V2] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999. [SNMP-OVER] "AN OVERVIEW OF SNMP V2.0", Diversified Data Resources, Inc., http://www.ddri.com, 1999. [TIPHON] "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Inter-domain pricing, authorization, and usage exchange", TS 101 321 V1.4.2, December 1998. [XML] Bray, T., J. Paoli, and C. Sperberg-McQueen, "Extensible Markup Language (XML) 1.0", W3C Recommendation, February 1998. [XML-DATA] "XML Schema Part 2: Datatypes", W3C Working Draft 07 April 2000, April 2000. [XML-SCHM] "XML Schema Part 1: Structures", W3C Working Draft 7 April 2000, April 2000.
13. Authors' Addresses
Nevil Brownlee
Information Technology Systems & Services
The University of AucklandPhone: +64 9 373 7599 x8941 EMail: email@example.com
Alan Blount
MetraTech Corp.
330 Bear Hill Road
Waltham, MA 02451EMail: email@example.com
14. Full Copyright Statement
Copyright © The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.
The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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.
Funding for the RFC Editor function is currently provided by the Internet Society.


text:
A few months ago I dug up lots of information on getting to Jeju in South Korea, but I didn't find the prices.
Most of the websites are only in Korean so I'm throwing this one open to all our expert contributors. Which of the ferries to Jeju is cheapest?
Logically it could be the shortest / quickest. But you never know if that might involve a more modern or more luxurious ferry or a more expensive to run hydrofoil or something.
- Wando is probably the shortest crossing.
- Mokpo could also be short but the information I found at the time was inconsistent and varied by several hours.
(I'll be hitchhiking and nearly broke so I have no constraints as far as time, frequency, location - just price.)

subset: commoncrawl


text:
Fried Baked Potatoes |
Ah, Max. He's my older of two sons, and he's a quirky bird. He's a big fan of most fried potato foods: french fries, potato chips, potato pancakes, tater tots, etc. So, when I introduced him to a fried baked potato, he was in fried potato nirvana. A couple of months ago he even told me, as he picked up one of these little fried potatoes, "Mom, this is MY comfort food." Gosh, I love that kid.
My mom used to cut up day-old baked potatoes and fry them in a little bit of oil in her trusty cast-iron skillet. I tried that, but there were too many little potato pieces that would stick to the bottom, and that not only made the pan hard to clean, but then I didn't get to eat all that brown crispy potato goodness that was stuck to the pan. So, why not just fill up the pan with more oil and fry them like french fries? Yeah, why NOT? So, that's what I did. Mind you, I only do this occasionally because it just seems sort of wrong. Baking a potato and then cutting it up and deep frying it, but it makes the potato so crisp and succulent. They sort of remind me of those potato skin appetizers we would order at Black Angus. Do they even sell those any more?
So, anyway, I'm making these for Max tonight while my little eating buddy Ezra and I enjoy some of our favorite pasta.
Max's Favorite Potatoes/Fried Baked Potatoes
- 1 or more baked potatoes, fresh or day old
- canola oil for frying
- salt to taste
If you don't quite know how to bake a potato, you just preheat an oven to 400 degrees Fahrenheit. Scrub potatoes (any kind will do) and cut off a little bit of each end (like 1/8 inch) and carefully pierce each potato about 5-8 times with a sharp knife. Bake at 400 degrees for about an hour, or until potatoes just yield when squeezed with an oven-mitted hand. Then remove from the oven.
If you opt for fresh baked potatoes, be careful when cutting them so you don't get burned and so you don't crush them. Cut potatoes into 1-inch chunks.
Fill a frying pan with about 3/4 to 1 inch of canola oil and turn heat to medium-high. Put one potato chunk in the pan.* When it starts bubbling and frying, carefully slide in the rest of the potato chunks. I use my grease screen to help me with this by putting the potatoes on the screen and shimmying the potatoes into the oil (see video below). Make sure potatoes are evenly distributed in the pan.
Allow the potatoes to cook until deep golden brown, turning only occasionally and gently at that. Once they reach the desired color, remove to a paper towel-lined plate and salt to taste.
Makes 1 to infinity servings.
*When this potato starts bubbling, the oil is ready for the rest of the potatoes. |


text:
The 1914 Wonderground Underground
Map, a mixture of cartoon, fantasy, and topological accuracy, by Macdonald
I love this map, and this article! Of course, one of the reasons I love the article (link below) is that it's about the London Underground, and it incorporates a lot of
interesting historical background and contextual detail.
Another reason is that it is written in a rather meandering way, going
off on tangents that eventually lead back to the story at hand. Naturally, I admire this style of writing! And, most unusually, I have nothing more to
add. Thanks, Andrew M., for sending the
link to the map, which allows you to zoom around the map and see all the incredible detail. http://www.bbc.co.uk/news/magazine-25551751


text:
Slony-I 2.1.4 Documentation | ||||
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slon is the daemon application that "runs" Slony-I replication. A slon instance must be run for each node in a Slony-I cluster.
- -d log_level
The log_level specifies which levels of debugging messages slon should display when logging its activity.
The nine levels of logging are:
The first five non-debugging log levels (from Fatal to Info) are always displayed in the logs. In early versions of Slony-I, the "suggested" log_level value was 2, which would list output at all levels down to debugging level 2. In Slony-I version 2, it is recommended to set log_level to 0; most of the consistently interesting log information is generated at levels higher than that.
- -s SYNC check interval
The sync_interval, measured in milliseconds, indicates how often slon should check to see if a SYNC should be introduced. Default is 2000 ms. The main loop in
sleeps for intervals of sync_interval milliseconds between iterations.Short sync check intervals keep the origin on a "short leash", updating its subscribers more frequently. If you have replicated sequences that are frequently updated without there being tables that are affected, this keeps there from being times when only sequences are updated, and therefore no syncs take place
If the node is not an origin for any replication set, so no updates are coming in, it is somewhat wasteful for this value to be much less the sync_interval_timeout value.
- -t SYNC interval timeout
At the end of each sync_interval_timeout timeout period, a SYNC will be generated on the "local" node even if there has been no replicable data updated that would have caused a SYNC to be generated.
If application activity ceases, whether because the application is shut down, or because human users have gone home and stopped introducing updates, the slon will iterate away, waking up every sync_interval milliseconds, and, as no updates are being made, no SYNC events would be generated. Without this timeout parameter, no SYNC events would be generated, and it would appear that replication was falling behind.
The sync_interval_timeout value will lead to eventually generating a SYNC, even though there was no real replication work to be done. The lower that this parameter is set, the more frequently slon will generate SYNC events when the application is not generating replicable activity; this will have two effects:
The system will do more replication work.
(Of course, since there is no application load on the database, and no data to replicate, this load will be very easy to handle.
Replication will appear to be kept more "up to date."
(Of course, since there is no replicable activity going on, being "more up to date" is something of a mirage.)
Default is 10000 ms and maximum is 120000 ms. By default, you can expect each node to "report in" with a SYNC every 10 seconds.
Note that SYNC events are also generated on subscriber nodes. Since they are not actually generating any data to replicate to other nodes, these SYNC events are of not terribly much value.
- -g group size
This controls the maximum SYNC group size, sync_group_maxsize; defaults to 6. Thus, if a particular node is behind by 200 SYNCs, it will try to group them together into groups of a maximum size of sync_group_maxsize. This can be expected to reduce transaction overhead due to having fewer transactions to COMMIT.
The default of 6 is probably suitable for small systems that can devote only very limited bits of memory to slon. If you have plenty of memory, it would be reasonable to increase this, as it will increase the amount of work done in each transaction, and will allow a subscriber that is behind by a lot to catch up more quickly.
Slon processes usually stay pretty small; even with large value for this option, slon would be expected to only grow to a few MB in size.
The big advantage in increasing this parameter comes from cutting down on the number of transaction COMMITs; moving from 1 to 2 will provide considerable benefit, but the benefits will progressively fall off once the transactions being processed get to be reasonably large. There isn't likely to be a material difference in performance between 80 and 90; at that point, whether "bigger is better" will depend on whether the bigger set of SYNCs makes the LOG cursor behave badly due to consuming more memory and requiring more time to sortt.
In Slony-I version 1.0, slon will always attempt to group SYNCs together to this maximum, which won't be ideal if replication has been somewhat destabilized by there being very large updates (e.g. - a single transaction that updates hundreds of thousands of rows) or by SYNCs being disrupted on an origin node with the result that there are a few SYNCs that are very large. You might run into the problem that grouping together some very large SYNCs knocks over a slon process. When it picks up again, it will try to process the same large grouped set of SYNCs, and run into the same problem over and over until an administrator interrupts this and changes the -g value to break this "deadlock."
In Slony-I version 1.1 and later versions, the slon instead adaptively "ramps up" from doing 1 SYNC at a time towards the maximum group size. As a result, if there are a couple of SYNCs that cause problems, the slon will (with any relevant watchdog assistance) always be able to get to the point where it processes the troublesome SYNCs one by one, hopefully making operator assistance unnecessary.
- -o desired sync time
A "maximum" time planned for grouped SYNCs.
If replication is running behind, slon will gradually increase the numbers of SYNCs grouped together, targeting that (based on the time taken for the last group of SYNCs) they shouldn't take more than the specified desired_sync_time value.
The default value for desired_sync_time is 60000ms, equal to one minute.
That way, you can expect (or at least hope!) that you'll get a COMMIT roughly once per minute.
It isn't totally predictable, as it is entirely possible for someone to request a very large update, all as one transaction, that can "blow up" the length of the resulting SYNC to be nearly arbitrarily long. In such a case, the heuristic will back off for the next group.
The overall effect is to improve Slony-I's ability to cope with variations in traffic. By starting with 1 SYNC, and gradually moving to more, even if there turn out to be variations large enough to cause PostgreSQL backends to crash, Slony-I will back off down to start with one sync at a time, if need be, so that if it is at all possible for replication to progress, it will.
- -c cleanup cycles
The value vac_frequency indicates how often to VACUUM in cleanup cycles.
Set this to zero to disable slon-initiated vacuuming. If you are using something like pg_autovacuum to initiate vacuums, you may not need for slon to initiate vacuums itself. If you are not, there are some tables Slony-I uses that collect a lot of dead tuples that should be vacuumed frequently, notably pg_listener.
In Slony-I version 1.1, this changes a little; the cleanup thread tracks, from iteration to iteration, the earliest transaction ID still active in the system. If this doesn't change, from one iteration to the next, then an old transaction is still active, and therefore a VACUUM will do no good. The cleanup thread instead merely does an ANALYZE on these tables to update the statistics in pg_statistics.
- -p PID filename
pid_file contains the filename in which the PID (process ID) of the slon is stored.
This may make it easier to construct scripts to monitor multiple slon processes running on a single host.
- -f config file
File from which to read slon configuration.
This configuration is discussed further in Slon Run-time Configuration. If there are to be a complex set of configuration parameters, or if there are parameters you do not wish to be visible in the process environment variables (such as passwords), it may be convenient to draw many or all parameters from a configuration file. You might either put common parameters for all slon processes in a commonly-used configuration file, allowing the command line to specify little other than the connection info. Alternatively, you might create a configuration file for each node.
- -a archive directory
archive_dir indicates a directory in which to place a sequence of SYNC archive files for use in log shipping mode.
- -x command to run on log archive
command_on_logarchive indicates a command to be run each time a SYNC file is successfully generated.
See more details on slon_conf_command_on_log_archive.
- -q quit based on SYNC provider
quit_sync_provider indicates which provider's worker thread should be watched in order to terminate after a certain event. This must be used in conjunction with the -r option below...
This allows you to have a slon stop replicating after a certain point.
- -r quit at event number
quit_sync_finalsync indicates the event number after which the remote worker thread for the provider above should terminate. This must be used in conjunction with the -q option above...
- -l lag interval
lag_interval indicates an interval value such as 3 minutes or 4 hours or 2 days that indicates that this node is to lag its providers by the specified interval of time. This causes events to be ignored until they reach the age corresponding to the interval.
Warning There is a concommittant downside to this lag; events that require all nodes to synchronize, as typically happens with SLONIK FAILOVER and SLONIK MOVE SET, will have to wait for this lagging node.
That might not be ideal behaviour at failover time, or at the time when you want to run SLONIK EXECUTE SCRIPT.


text:
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Meet Future Colleagues


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Malick Sidibé began making photographs when portrait photography was understood as a a way to express status both in the present and as a memento for posterity. An idea that originated with the portraiture of medieval and Renaissance Europe, when royalty was painted surrounded by their wealth and treasures, this idea reached Mali through Western occupation and colonization and was transformed into its own genre there. In the 1950s, Sidibé was commissioned to photograph people just after they had bought new clothes or had their hair done in a new fashion— the vocabulary of importance for people in the capital, Bamako, at the time.
However, in the 1960s and beyond, many young people in Bamako wanted to align themselves with the world outside Mali. They looked toward popular culture in the United States and Europe as an emblem of progress. Sidibé felt a genuine connection with these young people and saw the energy in their changing worldviews. They invited him to their parties, and he was able to record moments of their lives that were never before captured with a camera. His portfolio is stocked with photos of young Bamakoise hanging out or dancing, alongside studio portraits of the same men and women wearing traditional clothing. It was important to him that his studio be a welcoming, social center for all facets of Bamakoise life.
This change in values and lifestyle was directly connected to the recent independence of Mali, which was under French colonial rule from 1892 until 1960. These photographs capture Mali's transition from a French colony into a young, independent, and determinedly modern nation. Sidibé's subjects are both witness to and participants in this political and social transformation. The sitters are united by a pervasive and palpable sense of self-possession and agency. Sidibé aided this fledgling self-determination through posing and props, stating, "I didn't want my subjects to look like mummies. … When you look at my photos, you are seeing a photo that seems to move before your eyes."
–Jonah Jablons '17, Alicia Russo '17, and Sanjana Gothi '17
From the exhibition: If I Had Possession Over Judgement Day: Collections of Claude Simard (April 22 – September 24, 2017)


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Long Weekend Ideas
Our next long weekend in fast approaching! Check out our activities and ideas for a fun-filled weekend.
Everyone looks forward to long weekends, well at least we do! They provide us with the opportunity to squeeze something into our schedule that we otherwise wouldn't have time for. This may involve spending precious time with loved ones and friends, some much needed alone time, or time to explore what's on offer in your town or city.
However, our upcoming long weekends are going to look a little bit different to those of the past. With travel restrictions and social distance regulations in place, it is time to think outside the box. How are you going to spend enjoy that extra bonus day off?
The great news is, we are here to provide you with some great ideas. Below is a host of activities for you to participate in over the upcoming long weekend! Some are quiet, around the home activities whole others are getting back to nature.
Why not get the whole household involved in cooking/baking up a storm over the weekend? It is a great opportunity to try out new recipes and meal ideas while you have the time! Click here for some great healthy and wholesome meal ideas.
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Home Fitness Network Activities:
Why not get active whilst staying at home? Even though restrictions have lifted and you are allowed to venture away from the confines of your home, why risk it? We have numerous workouts which cover varying fitness levels, mindfulness activities, as well as fun activities specifically aimed at children on our Home Fitness Network Platform! Keeping active is essential during these times. Active bodies can help boost morale, keep your mind in a positive place, as well as help you continue to feel energized. It is even more important to keep the kids active and moving. Too much screen and device time can have an adverse effect on a young persons development. You can be rest assured that the little ones will enjoy a change of routine as well as spending quality time with the family. Valuable time that in other circumstances they may not have had time to do. Check out what we have to offer here.
Desperate to get out of the house?
We have some very exciting news as well! With the relaxation of social distancing regulations, we have been able to open a number of our outdoor pools, as well as start up outdoor bootcamps! The centres have been working hard to ensure we are abiding by the social distancing regulations, as well as adhering to strict hygiene measures. To view how we are going about abiding by these regulations, and to see which centre's are opening, please click here.
Other ideas
Other suggestions that are also socially distant and will take you away from the comforts of your own home are as follows: Heading to the great outdoors for a leisurely hike at your nearest National Park, enjoying a picnic with less than 10 friends at the local park, ordering local takeaway and eating it at a nearby beach, park, riverbank or in the comfort of your own home/back yard! You could have a Pinterest inspired home camping night in the back yard or a living room sleepover. Take a walk along the waterfront or local trails. A leisurely bike ride is always a pleasant way to spend a few hours. If caravan parks are open for local travel in your State, then why not head there! Support local business where you can!


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C-HCGU system, Branch region. On the 14th of April at 17:49 EVE Standard Time, a capital battle unfolded in the system over a Triumvirate. [TRI] tower.
The tower in question had been anchored by the alliance to serve as a forward operations base for its forces as it continues its feud with Guardians of the Galaxy (GotG) coalition. The structure was in the process of becoming operational when a GotG combat carrier warped to the grid and deployed fighter squadrons in order to destroy it. Triumvirate. forces quickly organized a squadron of black ops battleships and jumped them into the system on top of said combat carrier.
GotG forces reacted, lighting a cynosural beacon a 100 kilometers from the carrier itself and bringing in two squadrons of mixed battleships. Realizing the danger, the majority of the black ops battleships quickly retreated, with only one teleporting into the battleship formation by mistake which was subsequently destroyed.
Triumvirate. forces were not ready to back down and quickly formed a Tengu strategic cruiser fleet which hurried to the system. At the same time the alliance started organized several dreadnoughts in case of an escalation. The smallish fleet burned back to the system to continue fighting only to find GotG had reinforced the combat carrier with an additional four combat carrier squadrons. Regardless the Tengu fleet warped in to engage while calling on allies. Pandemic Legion [-10.0] answered the call and quickly formed a 70 pilot Proteus strategic cruiser fleet. The force made way to the system utilizing wormholes.
Triumvirate. forces landed near the combat carriers who swiftly responded to the intruders. The combat carriers had deployed their compliments of fighters to destroy the tower but turned them instead on the strategic cruisers. The cloud of fighters descended on the strategic cruisers, swarming their hulls and destroying several ships in the process. Triumvirate. had no time to waste and had a cynosural beacon lit up on the GotG force while rousing pilots to join the fleet with more dreadnoughts. Two Minokawa force auxiliaries were also procured to aid in the strategic cruisers' survival.
The Triumvirate. dreadnought force, two squadrons strong, jumped through and landed on top of the GotG capital ships. The dreadnoughts entered their siege cycles and opened fire on the combat carriers at point blank range. In rapid succession, combat carriers and force auxiliaries were felled by the dreadnoughts. The Triumvirate. force tore through the hostile capital ships but the fight was far from one sided. GotG brought in a couple of dreadnought squadrons of its own into the fight. The dreadnoughts entered their respective siege cycles and opened fire on their hostile counterparts.
Out of Sight. [OOS] also came in to aid GotG. The alliance had been notified of the battle as it progressed and managed to muster a squadron of dreadnoughts as well as interdictors to aid GotG. The Out of Sight. dreadnoughts entered the fray, choosing to jump in at range of the unfolding melee. The Out of Sight. dreadnoughts positioned themselves nearly 100 kilometers from the maelstrom, using long range guns as they coordinated their barrages.
Triumvirate.'s Tengu fleet continued to aid its capital ships in their struggle. With the Minokawas' assistance and the dreadnoughts presenting a more pressing target, it was able to remain in the thick of the fighting and contribute. It was soon joined by the Pandemic Legion strategic cruisers which warped in and added their firepower to the mix. The battle quickly turned into a gruesome exchange as the two sides traded capital ships. Two thirds of the GotG combat carrier force had been destroyed by that point but the dreadnought exchange was far from over. With their dreadnought numbers, GotG and allies managed to destroy the vast majority of Triumvirate.'s capitals. Only three ships managed to escape the slaughter.
With Triumvirate.'s dreadnoughts in ruin, GotG and allies attempted to extract their remaining capitals. A medium sized Machariel battleship fleet arrived in the system to fend off the Pandemic Legion and Triumvirate. fleets which continued to hold down some of the GotG capitals. Out of Sight. for its part managed to extract with relative ease, jumping its dreadnought force out without incident. Its interdictors however remained in the system, covering gates so as to slow down and halt hostile reinforcements.
The GotG Machariels warped in to engage the hostile forces, the two sides exchanging blows at close range. Even without their dreadnought force, Triumvirate. supported by Pandemic Legion proved too much for the battleships to handle. Coming under heavy fire from the combined force of the strategic cruisers, battleship after battleship succumbed to the damage. GotG casualties piled up fast while the two alliances were steadfast, giving no ground. The GotG Machariel fleet had no choice but to retreat leaving the strategic cruisers in control of the field. During the exchange, GotG managed to extract its remaining capital force.
With the field under their control, Triumvirate. and Pandemic Legion looted the field and started to withdraw their forces. The tower, forgotten in the fighting, had managed to online. This meant Triumvirate. managed to achieve its strategic goal. With the battle and objective won, Triumvirate. and Pandemic Legion left the system, bringing an end to the fighting.
Battle report for the C-HCGU system can be found here.
All told the battle on its various stages lasted for 62 minutes with Time Dilation not reported by combatants as being a major issue. The system itself is estimated to have held 300 pilots at the peak of the fighting though this number has not been verified.
Triumvirate. and Pandemic Legion lost a combined 48 ships including 21 dreadnoughts, 2 force auxiliaries and 3 strategic cruisers for a total of 84.89 billion ISK damage.
GotG and Out of Sight. lost a combined 88 ships including 2 dreadnoughts, 5 force auxiliaries, 24 combat carriers and 26 battleships for a total of 96.15 billion ISK damage.
Salivan Harddin is a member of Hoover Inc., Pandemic Legion, and covers battles across New Eden