HP A7533A HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, Dece - Page 366

• desired_distance is, for an LD-mode link, a threshold limit for link distance to ensure buffer availability for other ports in the same port group. If the measured distance exceeds desired_distance, desired_distance is used. For an LS-mode link, desired_distance is used to calculate the buffers required for the port. 5. Repeat step 4 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. The following example configures slot 1, port 1 for the LD link distance mode, enables the extended link initialization sequence, and sets the desired distance to 50 kilometers: switch:admin> portcfglongdistance 1/1 LD 1 50 Table 77 lists the extended ISL modes for switches with Bloom-based ASICs. You can configure extended ISL modes with the portCfgLongDistance command when the Extended Fabrics license is activated. Table 77 Extended ISL modes: B-Series 2Gb Switches (Bloom and Bloom II ASICs) Mode Buffer allocation Distance @ 1 1 Gbps 2 Gbps Gbps Distance @ 2 Gbps Earliest Fabric OS release Extended Fabrics license required? L0 5 (26)1 5 (26) 10 km 5 km All No LE 13 19 n/a 10 km 3.x, 4.x No LD2 Auto Auto Auto Auto Maximum is 200 km Maximum is 100 km 3.1.0, 4.1.0, Yes 4.4.0, 5.x (depending on the model) LS3 Based on Based on Based on Based on 5.1.0 Yes user-spec user-spec user-specified user-specified ified ified distance distance distance distance Maximum is 200 km Maximum is 100 km 1. For each data channel (in this case, there are 4) there are 5 credits, plus 6 extra credits. 2. The dynamic long-distance mode (LD) automatically configures the number of buffer credits required, based on the actual link distance. 3. The static long-distance mode (LS) allocates the number of buffer credits based on the user-specified distance. 366 Administering extended fabrics