Dell Brocade 6520 Command Reference Supporting Fabric OS v7.1.0 - Page 188

2 configure Per-frame Route Priority In addition to the eight virtual channels used in frame routing priority, support is also available for per-frame-based prioritization when this value is set. When Per-frame Route Priority is set to 1, the virtual channel ID is used in conjunction with a frame header to form the final virtual channel ID. Long Distance Fabric When this mode is set to 1, ISLs in a fabric can be up to 100 km long. The exact distance level is determined by the per-port configuration on the E_Ports of each ISL. Both E_Ports in an ISL must be configured to run the same long-distance level; otherwise, the fabric will be segmented. An Extended Fabrics license is required to set this mode. BB Credit The buffer-to-buffer (BB) credit represents the number of buffers available to attached devices for frame receipt. The range of allowed values varies depending on other system settings (see Unicast-only Operation). Refer to the Fabric OS Administrator's Guide for more information on platform-specific BB Credit limitations. Insistent Domain ID Mode When this mode is set, the switch attempts to acquire from the fabric the domain number programmed in its "Switch Fabric Settings." If the operation fails, the switch will segment from the fabric. You must disable the switch before configuring this parameter. Disable Default PortName When this mode is set, the switch does not generate a default port name. Edge hold time Configures the maximum time a frame can wait after it is received on the ingress port and before it is delivered to the egress port. If the frame waits in the egress buffer for more than the configured hold time, the switch drops the frame, replenishes sender's credit, and increments the counters sts_tx_timeout and er_c3_timeout on the TX and RX ports respectively. The frame-timeout indicates a slow draining or a congestion or bottleneck in the fabric. Decreasing hold time on the edge switches may reduce frame drop counts in the core switches. This parameter is stored persistently in the configuration file. You can configure edge hold time on both default and logical switch. The edge hold time configuration is a chip-based value and the configuration varies between Condor2-based platforms and Condor3-based platforms. Condor2-based platform provides one register to store the edge hold time value and any change in this value will affect all ports in the chip. Therefore, the edge hold time configuration will not be changed for Condor2-based platform ports in a logical switch. The Condor2-based platform ports in a logical switch take the default edge hold time value (220 milliseconds) or the value configured in the default switch. Condor3-based platform provides four registers to store the edge hold time configuration and therefore each port in a chip can be configured one of the four values. The edge hold time parameter is enabled by default with a value of 500 milliseconds. The following are the three predefined edge hold time values: 80 Low edge hold time (in milliseconds). 220 Medium edge hold time (in milliseconds). 500 High edge hold time (in milliseconds). This is the default value. 160 Fabric OS Command Reference 53-1002746-01