Default CBS and MBS for queues

Table: Default CBS and MBS values
Platforms	CBS (Kbytes)		MBS (Kbytes)
Platforms	Network queue and access-uplink queue	Access queue	Network queue and access uplink queue	Access queue
7210 SAS-D	8.4	8.4	See^¹	See^¹
7210 SAS-Dxp 12p	9	9	See^²	See^²
7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p	4.5 (for 1 GE ports) 9 (for 10 GE ports)	4.5 (for 1 GE ports) 9 (for 10 GE ports)	See^³	See^³

¹ On 7210 SAS-D, the per-port MBS pool mode is used. With it, the maximum MBS per queue, assuming no other queues on the same port have any traffic, is 78 Kbytes. The show>pool port ID>access-egress and show>pool port ID>access-uplink-egress commands are available to display the values in use depending on the port mode (either access or access-uplink).

² On 7210 SAS-Dxp 12p, the per-port MBS pool mode is used. With it, the maximum MBS per queue, assuming no other queues on the same port have any traffic, is 65 Kbytes. The show>pool port ID>access-egress and show>pool port ID>access-uplink-egress commands are available to display the values in use depending on the port mode (either access or access-uplink).

The 7210 SAS-Dxp 12p also supports a decommissioning feature with per-port MBS pool mode. With it, the per-port MBS pool can be increased by taking away packet buffers from other ports. In this case, the maximum MBS per queue, assuming no other queue has any traffic on that port, depends on the user configuration. For example, assuming one port is decommissioned and its buffers are allocated to port 1/1/1, the maximum MBS per queue on port 1/1/1, assuming no other queues have any traffic, is equivalent to 202 Kbytes.

³ On 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p, the per-port MBS limit mode is used. With it, the maximum MBS per queue, assuming no other queues on the same port have any traffic, is 150 Kbytes. The maximum MBS limit per port is 200 Kbytes (the CBS buffers available on that port are in addition to the per-port MBS limit).The show>pool port ID>access-egress and show>pool port ID>access-uplink-egress commands are available to display the values in use depending on the port mode (either access or access-uplink).

The 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p also support a decommissioning feature with per-port MBS limit mode. With it, the per-port MBS pool can be increased by taking away packet buffers from other ports. In this case, the maximum MBS per queue, assuming no other queue has any traffic on that port, depends on the user configuration. For example, assuming one port is decommissioned and its buffers are allocated to port 1/1/1, the maximum MBS limit per queue on port 1/1/1, assuming no other queues have any traffic, is equivalent to 186 Kbytes. The maximum MBS limit per port is equivalent to 236 Kbytes (the CBS buffers available on that port are in addition to the per-port MBS limit).