Figure 66: tos field in an ip header – Allied Telesis AT-S62 User Manual
Page 223
AT-S62 Menus Interface User’s Guide
Section II: Advanced Operations
223
Protocol (Layer 2)
Traffic flows can be identified by any of the following Layer 2 protocols:
❑ IP
❑ ARP
❑ RARP
❑ Protocol Number
Observe the following guidelines when using this variable:
❑ This variable must be left blank or set to IP when setting a Layer3
or Layer 4 variable.
❑ To specify a protocol by its number, you can enter the value in
decimal or hexadecimal format. If you choose hexadecimal,
precede the number with the prefix “0x”.
IP ToS (Type of Service) (Layer 3)
Type of Service (ToS) is a standard field in IP packets. It is used by
applications to indicate the priority and Quality of Service for a frame.
The range of the value is 0 to 7. The location of the field is shown in
Figure 66.
Figure 66 ToS field in an IP Header
0
ver
IHL
0
3
7
ToS
total length
15
31
. . .
1
2
3
4
5
6
7
DSCP value
Precedence