Cos-Queue Mapping - Comtrol RocketLinx ES7528 User Manual

CoS-Queue Mapping

CoS-Queue Mapping
Use this page to change the CoS values into a Physical Queue mapping table. Since the switch fabric of the RocketLinx
ES7528 only supports eight queues, Lowest, Low, Middle and High. You should therefore assign how to map CoS value to the
level of the physical queue.
Class of service (CoS) is a 3 bit field within a layer two Ethernet frame header defined by IEEE 802.1p when using 802.1Q
tagging. The field specifies a priority value of between 0 and 7 inclusive that can be used by Quality of Service (QoS)
disciplines to differentiate traffic.
While CoS operates only on Ethernet at the data link layer, other QoS mechanisms (such as DiffServ) operate at the network
layer and higher. Others operate on other physical layers. Although 802.1Q tagging must be enabled to communicate priority
information from switch to switch, some switches use CoS to internally classify traffic for QoS purposes.
Differentiated Services (DiffServ) is a model where traffic is treated by intermediate systems with relative priorities based on
the type of services (ToS) field. Defined in RFC2474 and RFC2475, the DiffServ standard supersedes the original specification
for defining packet priority described in RFC791. DiffServ increases the number of definable priority levels by reallocating
bits of an IP packet for priority marking. The DiffServ architecture defines the DiffServ field, which supersedes the ToS field
in IPv4 to make per-hop behavior (PHB) decisions about packet classification and traffic conditioning functions, such as;
metering, marking, shaping, and policing.
After configuration, press Apply to enable the settings.
Note: You must Save the settings (Page 137), if you want to maintain these settings if the RocketLinx ES7528 is powered off.
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CoS-Queue Mapping