Brocade Fabric OS Administrator's Guide Supporting Fabric OS v6.3.0 (53-1001336-02, November 2009)

446 Fabric OS Administrator’s Guide
53-1001336-02
Trunking over long distance fabrics
19
Trunking over long distance fabrics
In long-distance fabrics, if a port speed is set to autonegotiate, then the maximum speed, which is
8 Gbps, is assumed for reserving buffers for the port. If the port is only running at 2 Gbps, this
wastes buffers. On the Brocade 300, 4100, 4900, 5100, 5300, 5410, 5424, 5450, 5480, 7800,
8000, and 48000 platforms, for long-distance ports, you should specify the port speed instead of
setting it to autonegotiate.
Support for 8 Gbps is only between the following:
• Between the Brocade 48000 and Brocade DCX (including DCX-4S) platforms with the
appropriate 8-Gbps blades
• Between Brocade DCX (including DCX-4S) platforms with the appropriate 8-Gbps blades
• Between Brocade 300, 5100, 5300, 5410, 5424, 5450, and 5480 switches with the 8 Gbps
SFPs installed.
The Brocade 300, 5100, 5300, 5410, 5424, 5450, and 5480 support long-distance modes L0, LE,
LS, and LD. The distance supported on each platform depends on the available buffers, number of
back-end ports, and number of offline ports.
In addition to the criteria listed in “Criteria for managing trunking connections” on page 442,
observe the following criteria for trunking over extended fabrics:
• It is supported only on switches running Fabric OS v6.1.0 and later.
• Extended Fabrics and ISL Trunking licenses are required on all participating switches.
• When configuring long distance, the portCfgLongDistance --vc_translation_link_init
parameter must be set the same on all ports in an extended fabric.
For additional information on configuring long distance, see “Configuring an extended ISL” on
page 457. Table 84 describes Trunking over long distance support for the Brocade 4100 and 4900
platforms.
Table 85 describes Trunking over long distance support for the Brocade 48000, the DCX
Backbone, and the DCX-4S platforms and supported blades.
TABLE 84 Trunking support for Brocade 4100 and 4900
Long distance mode Distance Number of 2 Gbps ports Number of 4 Gbps ports
LE 10 km 32 (four 8-port trunks) 32 (four 8-port trunks)
LD 200 km 3 (one 3-port trunk) 0
LD 250 km 3 (one 3-port trunk) 0
LD 500 km 0 0
TABLE 85 Trunking over distance for the Brocade 48000, DCX Backbone, and the DCX-4S
Long distance mode Distance Number of 2 Gbps ports Number of 4 Gbps ports
LE 10 km 48 (six 8-port trunks) 48 (six 8-port trunks)
L0 Normal See note below 48 (six 8-port trunks)
LD 200 km 4 (one 2-port trunk per switch) 0
LD 250 km 4 (one 2-port trunk per switch) 0