User's Manual

System Configuration
106
5
• Priority
- CS Class – Class of Service (CoS) priority.
(Range: 0 - 7, where 7 is the highest priority: Default: 0)
This Gateway processes Class of Service (CoS) priority tagged traffic by using
eight priority queues for each port. Up to eight separate traffic priorities are
defined in IEEE 802.1p. The default priority levels are assigned according to
recommendations in the IEEE 802.1p standard as shown in the following table.
The priority levels recommended in the IEEE 802.1p standard for various
network applications are shown in the following table. However, you can map the
priority levels to the Gateway’s output queues in any way that benefits
application traffic for your own network.
- PHB – Per-Hop Behavior includes the following DiffServ queueing options:
- Best-Effort uses the lowest priority. BE (DSCP, Q=0)
- Assured Forwarding provides four priority classes. AF1X(DSCP,Q=1),
AF2X (DSCP, Q=2), AF3X (DSCP, Q=3), AF4X (DSCP, Q=4)
- Expedited Forwarding provides highest priority. EF (DSCP, Q=5)
- PHB Priority – Per-hop behavior, or the priority used for this router hop.
(Range: 0-7, where 7 is the highest priority)
Table 5-56 Mapping CoS Values to Egress Queues
Priority
01234567
Queue
20134567
Table 5-57 CoS Priority Levels
Priority Level Traffic Type
1Background
2 (Spare)
0 (default) Best Effort
3 Excellent Effort
4 Controlled Load
5 Video, less than 100 milliseconds latency and jitter
6 Voice, less than 10 milliseconds latency and jitter
7 Network Control