Max/Pri (Maximum Bandwidth/Priority) Qos Mode - Comtech EF Data CDM-570A Installation And Operation Manual

L.1.1

Max/Pri (Maximum Bandwidth/Priority) QoS Mode

In Max/Pri mode, up to 32 QoS rules can be configurable using source IP subnet, destination IP
subnet, source port range, destination port range, and protocol. For each created rule, you can
also set the QoS treatments such as priority, limiting the maximum bandwidth, WRED enable or
disable, and filter enable or disable.
Priority – The IP Packet Processor classifies each packet that is to be forwarded over the
satellite; the packet is then assigned a Priority Number (Priority level from 1 to 8) according to the
defined QoS Rules:
•
The lower the Priority Number, the higher that priority is (i.e., Priority 1 = highest priority;
Priority 9 = lowest priority).
•
Any latency critical traffic such as VoIP/RTP should always be assigned Priority 1.
•
Priority 1 packets are forwarded immediately; Priority 2 packets are forwarded as soon as
there are no Priority 1 packets in the Queue; and so on through Priority 8.
•
Any packet that does not meet a QoS Rule is assigned to the Default Rule with
Priority = 9.
Maximum Bandwidth – This can also be assigned to a flow to restrict the Maximum Bandwidth
that any particular flow will utilize; otherwise, the default of no bandwidth restriction can be
selected.
Filtering – QoS allows specific flows to be designated as "filtered" – this instructs the IP Packet
Processor to discard traffic that is otherwise not wanted for forwarding over a satellite link.
When you enable the FILTER option for a rule, QoS provides the ability to filter the packet
completely.
QoS Rule Hierarchy – It is quite possible to have traffic that meets the definitions of several QoS
Rules. All traffic will be classified into the first QoS Rule that is a match, or fall into the Default
Rule. The most specific QoS Rule will always be first. For example, a QoS Rule that identified a
Source and Destination IP Address would be assigned ahead of a rule that just defined RTP
protocol.
Advanced Quality of Service (QoS) Option
CDM-570A/570AL Satellite Modem with Optional Packet Processor
L–2
Revision 5
MN-CDM570A