Comtech EF Data CDM-570 - Manual (Page 221)

CDM-570/570L Satellite Modem with Optional IP Module Revision 12
Ethernet IP Module Interface MN/CDM570L.IOM
13–15
Minimum Bandwidth – Minimum specification that allows a committed information rate (CIR)
to be applied to user-defined classes of traffic; otherwise, the default of no minimum bandwidth
can be selected.
Filtering – Any specific flow can be designated as filtered (see Maximum Bandwidth/Priority
QoS).
QoS Rule Hierarchy – The QoS Rule Hierarchy is the same as Maximum Bandwidth/Priority
QoS.
QoS Statistics – QoS Statistics are displayed as Maximum Bandwidth/Priority QoS.
13.4.5.3 DiffServ QoS Mode
The IP Module QoS can also be set to DiffServ Mode to make it fully compliant to the
Differential Services QoS RFC standards.
Class Selector DiffServ Code Points (DSCP) – Some implementations of DiffServ will
prioritize traffic by Class Selector assignment. This is defined in the DiffServ Code Points
(DSCP) within the IP header. The first three bits of the DSCP define the Class Selector
Precedence (or Priority):
Class Selector DSCP IP Module Priority
Precedence 1 001 000
7
Precedence 2 010 000 6
Precedence 3 011 000 5
Precedence 4 100 000 4
Precedence 5 101 000 3
Precedence 6 110 000 2
Precedence 7 111 000 1
Default 000 000 9
The IP Module will prioritize the traffic based upon the DSCP Class Selector Precedence.
All traffic that does not have the DSCP Class Selector Precedence defined (000
000) will be placed in the Default Queue and have a Precedence of 9.
Expedited Forwarding and Assured Forwarding DSCP – Another implementation of DiffServ
uses all six bits of the DSCP to define Expedited and Assured Forwarding:
DiffServ Type Class Selector DSCP IP Module Priority
Expedited Forwarding Precedence 1 101 110 3
Assured Forwarding – Class 1 Precedence 8 001 xx0 7
Assured Forwarding – Class 2 Precedence 8 010 xx0 7
Assured Forwarding – Class 3 Precedence 8 011 xx0 7
Assured Forwarding – Class 4 Precedence 8 100 xx0 7