HP StorageWorks 2.32 Edge Switch - Manual (Page 178)

Optional features 178
If Enterprise Fabric Mode is enabled, this parameter is automatically enabled and cannot be
disabled unless the switch is off line. In this case, disabling Domain RSCNs also disables
Enterprise Fabric Mode.
• Insistent Domain Identification (ID)—This is a parameter in the Configure Switch
Parameters dialog box, available from the Configure menu in the Element Manager. Enabling
this option sets the domain ID configured in the Preferred Domain ID field of the Configure
Switch Parameters dialog box as the active domain identification when the fabric initializes. A
static and unique domain identification is required by the Fabric Binding feature because the
feature's Fabric Membership list identifies switches by WWN and Domain ID. If a duplicate
preferred domain ID is used, then set to insistent, warnings will occur when directors and
switches are added to a Fabric Membership List.
If Fabric Binding or Enterprise Fabric Mode is enabled, this option is automatically enabled and
cannot be disabled unless these options are disabled or the switch is off line. Disabling insistent
domain ID will disable Enterprise Fabric Mode and Fabric Binding.
See ” Enable/disable and Online State functions ” on page 172 for Fabric Binding, and ” Enabling
or disabling Switch Binding ” on page 174 for Switch Binding.
To enable and disable this option, refer to the Enterprise Fabric Mode section of the HP
StorageWorks HA-Fabric Manager user guide.
Open Trunking
Interswitch links (ISLs) connect ports between E_Ports on Fibre Channel switches and link these
switches into a multiswitch fabric. Multiple ISLs may be connected between the switches in the
fabric. Data from an attached end device (server or storage) flows through these ISLs to a target
end-device connected to a switch somewhere in the fabric. A data flow is data received from a
specified receive port that is destined for a port in a specified target domain (switch). The list of ISLs
that are candidates for being rerouted (to or from) is derived from the fibre shortest path first (FSPF)
algorithm.
The Open Trunking feature monitors the average data rates of all traffic flows on ISLs (from a receive
port to a target domain), and periodically adjusts routing tables to reroute data flows from
congested links to lightly loaded links and to optimize bandwidth use. The objective of open
trunking is to make the most efficient possible use of redundant ISLs between neighboring switches,
even if these ISLs have different bandwidths.
Load balancing among the ISLs does not require user configuration, other than enabling Open
Trunking. However, you can modify default settings for congestion thresholds (per port) and the Low
BB_Credit Threshold if desired.