Cisco Systems DSC9148D8G48PK9 manual Isl

Chapter 4 Configuring Interface Buffers

Information About Interface Buffers

Table 4-8 12-Port 4-Gbps Switching Module BB_Credit Buffer Allocation (continued)

BB_Credit Buffer Allocation Type

BB_Credit Buffers Per Port

Dedicated Rate Mode

4-Gbps Speed

ISL 1 Fx Port

Total number of BB_credit buffers per module

Total number of performance buffers per module

5488

512 (shared)

1. ISL = E port or TE port.

The following considerations apply to BB_credit buffers on 12-port 4-Gbps switching modules:

•BB_credit buffers for ISL connections can be configured from a minimum of 2 buffers to a maximum of 250 buffers.

•BB_credit buffers for Fx port mode connections can be configured from a minimum of 2 buffers to a maximum of 250 buffers.

•By default, 512 performance buffers are preallocated and are shared by all the ports. These buffers are configurable and the buffers are assigned to the port based on the availability of the buffers in the shared pool.

•There are 2488 extra buffers available as extended BB_credit buffers after allocating all the default BB_credit buffers for all the ports in ISL mode (5488 - (250 * 12)).

Note Extended BB_credits are allocated across all ports on the switch. That is, they are not allocated by port group.

Note By default, the ports in the 12-port 4-Gbps switching modules come up in 4-Gbps dedicated rate mode but can be configured as 1-Gbps and 2-Gbps dedicated rate mode. Shared mode is not supported.

	Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
4-14	OL-29284-01, Release 6.x