Filtering/QoS Information
GR2K-GA-0014
1-183
Ver. 07-02
When the upper protocol number is undefined or when numbers other than 6(TCP)
or 17(UDP) are defined in the upper protocol number.
2. The formula to calculate the TOS number is:
TOS number=precedence(0-7)x32+Delay(0,1)x16+
Throughput(0,1)x8+Reliability(0,1)x4
Examples of the calculated TOS number are shown below.
3. The upper 6 bits of the TOS field are replaced and the lower 2 bits are ignored
even if this parameter is set. Table 1-93 shows the TOS replacing value for
setting value. TOS value of output packet is the one that added TOS value lower 2
bits of output value to TOS replacing value. Replacing of DS field of Diff-serv is
executed by the same condition for TOS replacement.
Table 1-91 Combined Setting of Pair Switch and Possibility of Use
Item
Combined Setting of Pair
Switch (Note 2)
Possibility
of Use
Processing
1
-ip_pair_off
Possible
The source and destination IP addresses are
checked without being replaced.
•
Possible
2
-ip_pair
Possible
The source and destination IP addresses are
checked in both cases below.
•
When they are not replaced
•
When they are replaced
*:
-port_pair_off / -port_pair and -pair_synchronized_off/-pair_synchronized switches are invalidated
when the upper protocol number is undefined or when numbers other than 6(TCP) or 17(UDP) are
defined in the upper protocol number.
The calculation expression for obtaining a TOS value is as follows:
TOS value = precedence (0-7) x 32 ( Delay (0, 1) x 16 ( Throughput (0, 1) x 8 ( Reliability (0, 1) x 4
A calculation example of the TOS value is shown below.
Table 1-92 TOS Number Calculation
Precedence
Delay
Throughput
Reliability
TOS Number
0
0
0
0
0
1
0
0
0
32
2
0
0
0
64
3
0
0
0
96
4
0
0
0
128
5
0
0
0
160
6
0
0
0
192
7
0
0
0
224