Users Guide

Fabric OS Administrator’s Guide 589
53-1002920-02
Configuring an extended ISL
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• Static Mode (LS) — LS calculates a static number of buffer credits based only on a user-defined
desired_distance value. LS mode also assumes that all FC payloads are 2,112 bytes. Specify
LS mode to configure a static long-distance link with a fixed buffer allocation greater than 10
km.
Configuring an extended ISL
Before configuring an extended ISL, ensure that the following conditions are met:
• The ports on both ends of the ISL are operating at the same port speed, and can be configured
for the same distance_level without compromising local switch performance.
NOTE
A long-distance link also can be configured to be part of a trunk group. Two or more
long-distance links in a port group form a trunk group when they are configured for the same
speed and distance, and their link distances are nearly equal. For information on trunking
concepts and configurations, refer to Chapter 24, “Managing Trunking Connections”.
• Only qualified Brocade SFP transceivers are used. Only Brocade-branded or certain
Brocade-qualified SFP transceivers are supported.
1. Connect to the switch and log in using an account assigned to the admin role.
2. Enter the switchDisable command.
3. Enter the configure command to set the switch fabric-wide configurations.
Table 93 shows the fabric-wide settings that can be set:
4. For 8-Gbps platforms only, enter the portCfgFillword command to set ARB as the fill word. Refer
to the Fabric OS Command Reference for more for more information on configuring the fill
word for a single 8G FC port.
portcfgfillword [slot/]port, mode
The mode parameter in this command should be set to 3 if the vc_translation_link_init
parameter in the portCfgLongDistance command (in the next step) is set to 1.
5. Enter the portCfgLongDistance command.
portcfglongdistance [slot/]port [distance_level] [vc_translation_link_init]
[-distance desired_distance]
6. Repeat step 4 and step 5 for the remote extended ISL port. Both the local and remote
extended ISL ports must be configured to the same distance_level. When the connection is
initiated, the fabric will reconfigure.
TABLE 93 Fabric-wide settings
Field Type Default Range
Domain Number 1 Varies
R_A_TOV Number 10000 E_D_TOV * 2 to 120000
E_D_TOV Number 2000 1000 to R_A_TOV/2
WAN_TOV Number 0 0 to R_A_TOV/4
MAX_HOPS Number 7 7 to 19