Queue Sets - Nortel business policy switch 2000 User Manual

Queue sets

You can change the default IEEE 802.1p to queue mapping and the default DSCP
to IEEE 802.1p mapping using the Web-based management interface, SNMP, the
CLI, or DM. Note that the IEEE 802.1p to queue mapping for an interface (port)
depends on the number of queues available at that interface. This number depends
on the queue set associated with the interface.
The cascade port has a set of 2 queues that are serviced using an absolute priority
discipline. Filters are installed only on cascade ports that are connected to
BayStack 450 or BayStack 410 units in the stack.
BPS 2000 ports are associated with three types of queue sets:
• Queue set 1 has four queues. The first queue is serviced in an absolute priority
fashion. The other three queues are serviced in a WRR fashion.
• Queue set 2 has two queues that are serviced in an absolute priority fashion.
• Queue set 3 has eight queues. The first queue is serviced in an absolute
priority fashion. The other seven queues are serviced in a WRR fashion.
There are 3 sets of external ports that correspond to the queue sets. The first set of
external ports contains 24 10/100 Mb/s ports and the ports on the BPS2000-4TX
MDA, BSP2000-4FX MDA, and BPS2000-2FX MDA; these interfaces are
associated with queue set 1. Each port in this set has a set of 4 queues. The first
queue holds the highest priority and is serviced in an absolute priority fashion,
meaning that this queue is serviced first until all the queued packets are
transmitted. The other three queues are serviced using a WRR scheduler.
The second set of external ports contains the ports for the BayStack 450-1GBIC,
1SR, 1SX, 1LR, and 1LX MDAs. These interfaces are associated with queue set
2, which has 2 queues that are serviced in an absolute priority fashion.
The third set of external ports contains the MDA front panel ports for the
BPS2000-1GT, BPS2000-2GT, and BPS2000-2GE MDAs; these interfaces are
associated with queue set 3. Each port in this set has a set of 8 queues. The first
queue holds the highest priority and is serviced in an absolute priority fashion,
meaning that this queue is serviced first until all the queued packets are
transmitted. The other seven queues are serviced using a WRR scheduler.
Chapter 4 Policy-enabled networks 299
Using the Business Policy Switch 2000 Version 2.0