Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

434 Fabric OS Administrator’s Guide

53-1002148-02

ISL trunking over long distance fabrics

Tx: Bandwidth 16.00Gbps, Throughput 1.67Gbps (12.12%)

Rx: Bandwidth 16.00Gbps, Throughput 1.66Gbps (12.11%)

Tx+Rx: Bandwidth 32.00Gbps, Throughput 3.33Gbps (12.11%)

ISL trunking over long distance fabrics

both ports must have long distance enabled?

In long-distance fabrics, if a port speed is set to autonegotiate, then the maximum speed, which is

16 Gbps, is assumed for reserving buffers for the port. If the port is only running at 2 Gbps, this

wastes buffers. For long-distance ports, you should specify the port speed instead of setting it to

autonegotiate.

In addition to the criteria listed in “Supported configurations for trunking” on page 430, 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 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 448.

Table 75 describes Trunking over long distance support for the enterprise-class platforms and

supported blades.

NOTE

The L0 mode supports up to 5 km at 2 Gbps, up to 2 km at 4 Gbps, and up to 1 km at 8 Gbps.

The distance for the LS mode is static. You can specify any distance greater than 10 km.

The distance supported depends on the available buffers, number of back-end ports, and the

number of ports that are offline. For more information on setting port speeds, refer to Chapter 3,

“Performing Advanced Configuration Tasks”.

TABLE 75 Trunking over distance for the enterprise-class platforms

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

LD 500 km 0 0

LS Static See note below