HP P6000 Continuous Access Implementation Guide (T3680-96431, August 2012)

When using WDM, consider the following:
• WDM installation must conform to vendor specifications.
• Performance is affected by extreme distance and/or limited buffer-to-buffer credits on the Fibre
Channel switch.
• Some switch vendors may limit the maximum distance between sites.
Additional configuration rules apply to WDM configurations:
• Connecting the switch to the WDM unit typically requires one switch-to-WDM interface cable
per wavelength of multimode fiber.
• Switches may require an Extended Fabric license.
For more information about using WDM with fiber, see the HP SAN Design Reference Guide.
Fabric to IP
Extended fabrics convert Fibre Channel to IP to maximize the separation distance.
NOTE: Many solutions include dual fabrics between data centers to ensure there is no SPOF in
the event of a fabric failure, but redundant fabrics are not required to run HP P6000 Continuous
Access. Some best practice cabling solutions, such as the five-fabric configuration, do not support
dual-fabric solutions. See “Five-fabric configuration” (page 29).
Fibre Channel-to-IP
The remote replication configuration over IP is similar to the basic remote replication configuration
over fiber with the addition of Fibre Channel-to-IP (FC-to-IP) gateways. Dual fabrics require two
dedicated gateways at each site, one per fabric for a total of four per solution, to eliminate SPOFs.
See Figure 10 (page 31) and Figure 12 (page 34). For a current list of supported gateways and
network specifications, see the HP SAN Design Reference Guide.
FC-to-IP configuration limits
Remote replication over IP has the same configuration limits as described in “Basic configuration
limits” (page 23). Multiple instances can share the fabric if the network bandwidth is sufficient for
all traffic flowing between sites in a worst-case scenario.
In addition, some gateways do not support combining the data from two FC ports into one IP port.
For details, see the HP SAN Design Reference Guide and vendor documentation.
For information about different requirements for single intersite (interswitch) links versus shared or
dual intersite (interswitch) links, see the HP SAN Design Reference Guide.
FC-to-IP configuration rules
In addition to the “Basic configuration rules” (page 24), consider the following specific requirements
for IP configurations:
• Some FC-to-IP gateways are supported only on older B-series switches and require the Remote
Switch Key (vendor-dependent).
• For gateways requiring the Remote Switch Key, and on switches where the Remote Switch
Key is installed, do not enable suppression of F-Class frames. Doing so limits the supported
configuration to one switch per fabric at each site. See the HP SAN Design Reference Guide
for more information.
• The FC-to-IP gateways should be same model and software version on each side of the IP
network in the fabric.
• The first Fibre Channel switch at each end of an FC-to-IP gateway (the first hop) should be
same model and software version. This avoids interoperability issues because the MPX will
merge the fabrics.
Fabric to IP 25