Tos Prioritization - RuggedCom RuggedRouter RX1000 User Manual

®
RuggedRouter User Guide
Protocols that can be matched upon include tcp, udp, icmp, ospf, vrrp and ipsec.

TOS Prioritization

The priority of an IP packet can be derived from its Type of Service field. The TOS
field has the following format:
7
+---+---+---+---+---+---+---+---+
|
|PRECEDENCE |MD
|
+---+---+---+---+---+---+---+---+
The four TOS bits (the 'TOS field') are defined as:
MD - Minimize Delay,
•
MT - Maximize Throughput,
•
MR - Maximize Reliability,
•
MMC - Minimize Monetary Cost
•
As any (or all) of these bits may be set in a packet at a time, there are 16 possible
combinations. The router maps these combinations into the high, normal and low
priority queues as shown in the following table:
MD
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
184
6 5 4 3 2
| TOS Bits
MT MR
|
MT MR MMC
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
1 0
| |
MMC| 0 |
| |
Descriptions
Normal Service
Minimize Monetary Cost
Maximize Reliability
MR+MMC
Maximize Throughput
MT+MMC
MT+MR
MT+MR+MMC
Minimize Delay
MD+MMC
MD+MR
MD+MR+MMC
MD+MT
MD+MT+MMC
MD+MT+MR
MD+MT+MR+MMC
Priority Queue
Normal
Low
Normal
Normal
Low
Low
Low
Low
High
High
High
High
Normal
Normal
Normal
Normal
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