Comtech EF Data CDM-760 - Manual (Page 196)

Ethernet-based Remote Product Management Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
7–38
7.4.4.3.5.1.2 Configuration | WAN | QoS Page – DiffServ Mode
QoS can be set to DiffServ Mode to make it fully compliant to the Differentiated Services QoS
RFC (Request For Comments) standards.
(Banner and Menu Bar not shown)
Figure 7-16. Configuration | WAN | QoS Page (DiffServ Mode)
See Sect. 7.4.4.3.5.1 for information about the QoS Mode and SAR functions.
Differentiated Services
You have the option of configuring attributes for each queue (the acceptable ranges are shown
in brackets). Note the following (from left to right):
Column Description
Priority IP traffic is prioritized based upon the DSCP (DiffServ Code Points) Class Selector
Precedence.
Per-Hop Behavior (PHB) This is the traffic class that determines how packets will be forwarded.
Codepoint (DSCP)
This is the Codepoint value in the Type of Service (ToS) byte of the IP header.
Service Rate (kbps) [ -0.000 / (Tx Data Rate)] The minimum bandwidth is served first among the Assured
Forwarding (ASFD) classes in case of bandwidth availability, once Class Selector 7
through Class Selected 1 have been serviced.
Drop Precedences ASFD Class 4 through 1 Code Points (b100xx0, b011xx0, b010xx0, and b001xx0) carry
the drop precedence value (xx). In case of network congestion, a Weighted Random Early
Detection (WRED) congestion avoidance algorithm is imposed on these queues to drop
the packets randomly rather than ‘tail drop.’
The ASFD classes all take Priority 8 instead of their corresponding class
priorities (i.e., 1 through 4) to provide “Service Rate (kbps)” among all
ASFD classes.