The purpose of the Information rate information element is to notify the terminating user of the throughput indicated by the incoming Recommendation X.25 call request packet.
The Information rate information element is coded as shown in Figure 4-39 and Tables 4-29 and 4-30.
The maximum length of this information element is 6 octets.
Bits |
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8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
Octets |
Information rate Information element identifier |
||||||||
0 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
1 |
Length of information rate contents |
2 |
|||||||
1 ext. |
0 |
0 |
Incoming information rate |
3 |
||||
Spare |
||||||||
1 ext. |
0 |
0 |
Outgoing information rate |
4 |
||||
Spare |
||||||||
1 ext. |
0 |
0 |
Minimum incoming information rate |
5 |
||||
Spare |
||||||||
1 ext. |
0 |
0 |
Minimum outgoing information rate |
6 |
||||
Spare |
||||||||
Note - This information element applies only in the notification phase at the terminating exchange. If the throughput class facility/minimum throughput class facility is present in the X.25 incoming call packet the contents may be copied into the Information rate information element. The Information rate for the direction of data transmission from the calling user is copied into octet 3/5. The information rate for the direction of data transmission from the called user is copied into octet 4/6. The bit order should be preserved as described in Table 4-30. |
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Information rate information element
Information rate information element
Incoming/outgoing information rate (octets 3 and 4) |
The incoming outgoing information rate fields are used to indicate the information rate in the direction network to user, and user to network respectively. The information rate for the direction of data transmission from the calling DTE is indicated in bits 5, 4, 3, 2 and 1 of octet 3. The information rate for the direction of data transmission from the called DTE is indicated in bits 5, 4, 3, 2 and 1 of octet 4. The bits are coded as specified in Table 4-30. |
Minimum incoming/outgoing information rate (octets 5 and 6) |
The minimum information rate for the direction of data transmission from the calling DTE is indicated in bits 5, 4, 3, 2 and 1 of octet 5. The minimum information rate for the direction of data transmission from the called DTE is indicated in bits 5, 4, 3, 2 and 1 of octet 6. The bits are encoded as specified in Table 4-30. |
Throughput class coding
Bits |
|||||
Throughput class |
|||||
5 |
4 |
3 |
2 |
1 |
(bit/s) |
0 |
0 |
0 |
0 |
0 |
Reserved |