The purpose of the Transit delay selection and indication information element is to request the nominal maximum permissible transit delay applicable on a per call basis to that virtual call.
The Transit delay selection and indication information element is coded as shown in Figure 4-45 and Table 4-34.
The maximum length of this information element is 5 octets.
Bits |
||||||||
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
Octets |
Transit delay selection and indication Information element identifier |
||||||||
0 |
1 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
Length of transit delay selection and indication contents |
2 |
|||||||
0 ext. |
0 |
0 |
0 |
0 |
0 |
Transit delay selection and indication value |
3 |
|
Spare |
||||||||
0 ext. |
Transit delay selection and indication value (cont.) |
3a |
||||||
1 ext. |
Transit delay selection and indication value (cont.) |
3b |
||||||
Transit delay selection and indication information element
Transit delay selection and indication information element
Transit delay selection and indication value [octet 3 (bits 1-2), octets 3a and 3b] |
Transit delay value binary encoded in milliseconds. Bit 2 of octet 3 is the highest order bit and bit 1 of octet 3b is the lowest order bit. The transit delay value occupies 16 bits total. |
Note - For a Recommendation X.31[14] type of access to an ISDN the procedures only apply in the notification phase at the terminating exchange. At the terminating exchange, if the Transit Delay Selection and Indication facility is present in the X.25 [5] incoming call request packet, the two octet value should be copied into octets 3, 3a and 3b with the highest order bit contained in bit 2 of octet 3 and the lowest order bit contained in bit 1 of octet 3b. |