Forwarding classes

The 7210 SAS supports multiple FCs and class-based queuing, which means that the concept of FCs is common to all the QoS policies.

Each FC (also called Class of Service (CoS)) is important only in relation to the other FCs. An FC provides network elements with 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. The following table describes the FCs supported by the 7210 SAS.

Table: Forwarding classes
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	Intended for BE traffic.

Note:

Table: Forwarding classes lists the default definitions for the FCs. The FC behavior, in terms of ingress marking interpretation and egress marking, can be changed.