Comtech EF Data SLM-5650A Vipersat Parameter Editor - Manual (Page 60)

WAN
2-44 SLM-5650A Parameter Editor User Guide
Assured Forwarding
The Assured Forwarding PHB category serves general use traffic flows. This
group defines four service levels (Class 1 through Class 4) and also uses the last
three bits of the DSCP to define the Drop Probability or Precedence (Low,
Medium, or High). The Drop Precedence determines which packets will most
likely be dropped during periods of over congestion, similar to Weighted
Random Early Detection (WRED). As a result, each of the four AF service
levels also have three Drop Precedence levels for which the SLM-5650A
provides 12 separate queues.
An IP packet that best conforms to the flow criteria is assigned a Low drop
precedence, and thus has a higher probability of delivery during congestion than
a packet with a Medium (less conformance) or High (non-conformance) drop
precedence. The Low drop precedence level is preset to 100% of full to prevent
these packets from being dropped prior to the queue reaching its capacity.
Medium and High levels are configurable.
Figure 2-29 Assured Forwarding dialog
For Class 1 through 3, set the Service Rate (0 to Tx Data Rate, bps) and the
Maximum Queue Depth (1500-64000).
Specify the Precedence Levels for Medium Drop (20-90, % full) and High
Drop (10-80, % full).
Assured Forwarding Class 4 is pre-configured and the parameter fields are not
editable.