Cisco Systems DSC9148D8G48PK9 Extended BBCredits, Cisco MDS 9124 Fabric Switch BBCredit Buffers

Chapter 4 Configuring Interface Buffers

Information About Interface Buffers

Cisco MDS 9124 Fabric Switch BB_Credit Buffers

Table 4-12lists the BB_credit buffer allocation for MDS 9124 Fabric Switches.

Table 4-12	MDS 9124 Fabric Switch BB_Credit Buffer Allocation Defaults
		BB_Credit
		Buffers Per	BB_Credit Buffers Per Port
BB_Credit Buffer Allocation Type		Port Group	Defaults
			ISL1	Fx Port
Maximum user-configurable BB_credit buffers		64	61	61
Minimum user-configurable BB_credit buffers			2	1
Default BB_credit buffers		64	16	16

1. ISL = E port or TE port.

Cisco MDS 9222i Multiservice Modular Switch BB_Credit Buffers

Table 4-13lists the BB_credit buffer allocation for 18-port 4-Gbps Multiservice Modular switches.

Table 4-13	18-Port 4-Gbps Fabric Switch BB_Credit Buffer Allocation Defaults
		BB_Credit
		Buffers Per	BB_Credit Buffers Per Port
BB_Credit Buffer Allocation Type		Port Group	Defaults
			ISL1	Fx Port
User-configurable BB_credit buffers		4509	250	16

1. ISL = E port or TE port.

Extended BB_Credits

To facilitate BB_credits for long-haul links, the extended BB_credits feature allows you to configure the receive buffers above the maximum value on all Generation 2, Generation 3 and Generation 4 switching modules. When necessary, you can reduce the buffers on one port and assign them to another port, exceeding the default maximum. The minimum extended BB_credits per port is 256 and the maximum is 4095.

Note Extended BB_credits are not supported on the Cisco MDS 9148 Fabric Switch, Cisco MDS 9134 Fabric Switch, Cisco MDS 9124 Fabric Switch, the Cisco Fabric Switch for HP c-Class BladeSystem, and the Cisco Fabric Switch for IBM BladeCenter.

In general, you can configure any port in a port group to dedicated rate mode. To do this, you must first release the buffers from the other ports before configuring larger extended BB_credits for a port.

Note The ENTERPRISE_PKG license is required to use extended BB_credits on Generation 2, Generation 3 and Generation 4 switching modules. Also, extended BB_credits are not supported by ports in shared rate mode.

	Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x		4-17