Emerson 1552WU Reference Manual page 13

Reference Manual
00809-0100-4052, Rev AA
Figure 1-2. Ethernet Settings
Quality of service
In order to enhance the data traffic from the WirelessHART radio to the network the Quality of
Service (QoS) option has been included in the Ethernet Protocol page to allow selection of a
specific traffic control mechanism based on the various manners increase network performance
within a more comprehensive network. There are twenty-one options to choose from
(drop-down menu) as listed and described below, these are the Differentiated Services Cope
Point (DSCP) codes as a standard embedded into network messages IP header:


Initial Connection
Default: no specific traffic prioritization is selected
Assured forwarding (AF): this mechanism allows the data traffic to be prioritized based
on the required throughput, delay, jitter, loss or latency following an assured
forwarding per hop behavior. There are four AF Classes and each class has three drop
probabilities which are identified on the bits assignment at the IP header (first 6 bits
within Differentiated Services field)
Drop Class 1
Low AF 11
Medium AF 12
High AF13
Section 1: Initial Connection
Class 2 Class 3
AF 21 AF 31
AF22 AF 32
AF 23 AF 33
April 2015
Class 4
AF 41
AF 42
AF 43
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