Consider the following steps when you are planning for your FCIP TCP/IP links: Further details on GM planning are described in Chapter 6, “Copy services” on page 141. In addition to planning for your TCP/IP link, consider adhering to the following preferred  practices: FlashSystem 9100 HyperSwap technology provide Business Continuity solutions over  metropolitan areas with distances up to 300 km. Usually this is achieved using SAN extension  over WDM technology. Furthermore, in order to avoid single points of failure, multiple WDMs  and physical links are implemented. When implementing these solutions, particular attention  must be paid in the intercluster connectivity set up. For more information about FCIP, see the following publications: GLYPH<SM590000> For redundancy purposes use as many TCP/IP links between sites as you have fabrics in  each site that you want to connect. In most cases, there are two SAN FC fabrics in each  site, so you need two TCP/IP connections between sites. GLYPH<SM590000> Try to dedicate TCP/IP links only for storage interconnection. Separate them from other  LAN/WAN traffic. GLYPH<SM590000> Make sure that you have a service level agreement (SLA) with your TCP/IP link vendor  that meets your needs and expectations. GLYPH<SM590000> If you do not use Global Mirror with Change Volumes (GMCV), make sure that you have  sized your TCP/IP link to sustain peak workloads. GLYPH<SM590000> The use of FlashSystem 9100 internal Global Mirror (GM) simulation options can help you  test your applications before production implementation. You can simulate the GM  environment within one FlashSystem 9100 system without partnership with another. Use  the  chsystem  command with the following parameters to perform GM testing: – gminterdelaysimulation – gmintradelaysimulation GLYPH<SM590000> If you are not sure about your TCP/IP link security, enable Internet Protocol Security  (IPSec) on the all FCIP devices. IPSec is enabled on the Fabric OS level, so you do not  need any external IPSec appliances. GLYPH<SM590000> Set the link bandwidth and background copy rate of partnership between your replicating  FlashSystem 9100 to a value  lower  than your TCP/IP link capacity. Failing to do that can  cause an unstable TCP/IP tunnel, which can lead to stopping all your remote copy  relations that use that tunnel. GLYPH<SM590000> The best case is to use GMCV when replication is done over long distances. GLYPH<SM590000> Use compression on corresponding FCIP devices. GLYPH<SM590000> Use at least two ISLs from your local FC switch to local FCIP router. GLYPH<SM590000> On a Brocade SAN, use the Integrated Routing feature to avoid merging fabrics from both  sites. GLYPH<SM590000> IBM System Storage b-type Multiprotocol Routing: An Introduction and Implementation ,  SG24-7544 GLYPH<SM590000> IBM/Cisco Multiprotocol Routing: An Introduction and Implementation , SG24-7543 2.5.4 SAN extension with Business Continuity configurations Chapter 2. Storage area network  35