The 7210 SAS supports multiple FCs and class-based queuing, so the concept of FCs is common to all of the QoS policies. Each FC (also called Class of Service (CoS)) is important only in relation to the other FCs. A FC provides network elements a method to weigh the relative importance of one packet over another in a different FC.
Queues are created for a specific FC to determine the manner in which the queue output is scheduled. The FC of the packet, along with the in-profile or out-of-profile state, determines how the packet is queued and handled (the per hop behavior (PHB)) at each hop along its path to a destination egress point. Table: FCs describes the eight FCs supported by 7210 SAS.
The following table lists the default definitions for the FCs. The FC behavior, in terms of ingress marking interpretation and egress marking, can be changed by QoS policies.
FC-ID |
FC name |
FC designation |
DiffServ name |
Notes |
|---|---|---|---|---|
7 |
Network Control |
NC |
NC2 |
Intended for network control traffic. |
6 |
High-1 |
H1 |
NC1 |
Intended for a second network control class or delay/jitter sensitive traffic. |
5 |
Expedited |
EF |
EF |
Intended for delay/jitter sensitive traffic. |
4 |
High-2 |
H2 |
AF4 |
Intended for delay/jitter sensitive traffic. |
3 |
Low-1 |
L1 |
AF2 |
Intended for assured traffic. Also is the default priority for network management traffic. |
2 |
Assured |
AF |
AF1 |
Intended for assured traffic. |
1 |
Low-2 |
L2 |
CS1 |
Intended for BE traffic. |
0 |
Best Effort |
BE |
BE |