ITU-X75
X75 Packet structure: utilities list
| bits 8 _ _ _ _ _ _ 1 |
hex |
facilities type |
| 0 0 0 0 0 0 0 0 |
00 |
Utility marker: |
| 0 0 0 0 0 0 0 1 |
01 |
Reverse charging / fast select |
| 0 0 0 0 0 0 1 0 |
02 |
Throughput class indication |
| 0 0 0 0 0 1 1 1 |
07 |
Tariffs |
| 0 0 0 0 1 0 0 0 |
08 |
Called line address modified notification |
| 0 1 0 0 0 0 0 1 |
41 |
Transit network identification |
| 0 1 0 0 0 0 1 0 |
42 |
Packet size indication |
| 0 1 0 0 0 0 1 1 |
43 |
Window size indication |
| 0 1 0 0 0 1 0 0 |
44 |
RPOA selection |
| 0 1 0 0 1 0 0 1 |
49 |
Transit delay indication |
| 0 1 0 0 1 0 1 1 |
4A |
Clearing network identification code |
| 0 1 0 0 1 0 1 0 |
4B |
Transit delay selection |
| 1 0 0 0 0 0 0 1 |
81 |
Call identifier |
| 0 0 0 0 0 0 1 1 |
C3 |
Closed user group indication |
| 0 0 0 0 1 0 0 1 |
C7 |
Closed user group with outgoing access indication |
| TABLE 21/X.75 (ITU) |
|
The coding of the utility field is defined in § 5.4.3 Rec. X.75 (ITU).
X75 Packet structure: network utilities format
| bits 8 _ _ _ _ _ _ 1 |
Class |
Facilities code: class coding |
| 0 0 x x x x x x |
A |
single octet parameter field |
| 0 1 x x x x x x |
B |
double octet parameter field |
| 1 0 x x x x x x |
C |
triple octet parameter field |
| 1 1 x x x x x x |
D |
variable length parameter field |
| TABLE 20/X.75 (ITU) |
| |
|
| bits 8 _ _ _ _ _ _ 1 |
utilities field: class A format |
| 0 0 x x x x x x |
Utility code |
| octet 1 |
Utility parameter field |
| bits 8 _ _ _ _ _ _ 1 |
utilities field: class B format |
| 0 1 x x x x x x |
Utility code |
| octets 1-2 |
Utility parameter field |
| bits 8 _ _ _ _ _ _ 1 |
utilities field: class C format |
| 1 0 x x x x x x |
Utility code |
| octets 1-3 |
Utility parameter field |
| bits 8 _ _ _ _ _ _ 1 |
utilities field: class D format |
| 1 1 x x x x x x |
Utility code |
| octet 1 |
Utility parameter field length |
|
octets 2-n
|
Utility parameter field
|
|
01 - Reverse charging / Fast select
| - Octet : |
utility code |
| bits 8-1 |
01 H |
| - Octet 1: |
utility parameter field |
| bits 8-7 |
Fast select |
| bits 6-2 |
00000 |
| bit 1 |
Reverse charging |
| |
|
|
| bit 1 |
Reverse charging |
| 0 |
Reverse charging not requested |
|
1
|
Reverse charging requested
|
| |
|
|
| bits 8-7 |
Fast select |
| 0 0 |
Fast select not requested |
|
0 1
|
Fast select not requested
|
|
1 0
|
Fast select requested with no restriction on response
|
|
1 1
|
Fast select requested with restriction on response
|
|
02 - Throughput class indication
| - Octet : |
utility code |
| bits 8-1 |
02 H |
| - Octet 1: |
Coding of throughput class |
| bits 8-5 |
From the called STE |
| bits 4-1 |
From the calling STE |
|
|
|
| bits dcba |
Throughput class |
| 0 0 0 0 |
Reserved |
|
0 0 0 1
|
Reserved
|
|
0 0 1 0
|
Reserved
|
|
0 0 1 1
|
75
|
|
0 1 0 0
|
150
|
|
0 1 0 1
|
300
|
|
0 1 1 0
|
600
|
|
0 1 1 1
|
1200
|
|
1 0 0 0
|
2400
|
|
1 0 0 1
|
4800
|
|
1 0 0 1
|
4800
|
|
1 0 1 0
|
9600
|
|
1 0 1 1
|
19200
|
|
1 1 0 0
|
48000
|
|
1 1 0 1
|
64000
|
|
1 1 1 0
|
Reserved
|
|
1 1 1 1
|
Reserved
|
| TABLE 22/X.75 (ITU) |
|
07 - Tariffs
| - Octet : |
utility code |
| bits 8-1 |
07 H |
| - Octet 1: |
utility parameter field |
| bits 8-4 |
Primary tariff subfield (PPPPP) |
| bits 3-1 |
Secondary tariff subfield (UUU) |
| |
|
|
| bits 8-4 P P P P P |
Primary tariff subfield |
| 0 0 0 0 0 |
Subclass code 0: X.25 |
| 0 0 0 0 1 |
Subclass code 1: Switched access X.28 |
| 0 0 0 1 0 |
Subclass code 2: Dedicated access X.28 |
| 0 0 0 1 1 |
Subclass code 3:X.32 |
| 0 0 1 0 0 |
Subclass code 4:X.75 |
| 0 0 1 0 1 |
Subclass code 5-15: Reserved |
| to |
Subclass code 16-30: Reserved for national use |
| 0 0 0 0 0 |
Subclass code 31: Unspecified or non-standard |
|
08 - Called line address modified notification
| - Octet : |
utility code |
| bits 8-1 |
08 H |
| - Octet 1: |
utility parameter field |
| bits 8-1 |
Called line address modified notification |
| |
|
|
| bits 8 7 6 5 4 3 2 1 |
Called line address modified notification |
| 0 0 0 0 0 1 1 1 |
Call distribution within a hunt group |
| 0 0 0 0 0 0 0 1 |
Call redirection due to originally called DTE
busy |
| 0 0 0 0 1 0 0 1 |
Call redirection due to originally called DTE
out of order |
| 0 0 0 0 1 1 1 1 |
Call redirection due to prior request from originally
called DTE for systematic call redirection |
| 1 1 x x x x x x |
Called DTE originated (a) |
| 1 1 x x x x x x |
Call deflection by the originally DTE(b) |
|
(a): Each X may be independently set to 0 or 1 by the called
DTE and is passed transparently.
(b): The Xs are those set by the originally called DTE
in the call forwarding selection facility.
41 - Transit network identification
| - Octet : |
utility code |
| bits 8-1 |
41 H |
| - Octet 1: |
Identification code |
| bits 8-5 |
First digit (binary coded decimal) |
| bits 4-1 |
Second digit (binary coded decimal) |
| - Octet 2: |
Identification code |
| bits 8-5 |
Third digit (binary coded decimal) |
| bits 4-1 |
Fourth digit (binary coded decimal) |
|
42 - Packet size indication
| - Octet : |
utility code |
| bits 8-1 |
42 H |
| - Octet 1: |
utility parameter field |
| bits 8-5 |
0000 |
| bits 4-1 |
Packet size from the called STE |
| - Octet 2: |
futility parameter field |
| bits 8-5 |
0000 |
| bits 4-1 |
Packet size from the calling STE |
|
The values available for each direction are as follows:
| bits 4 3 2 1 |
Packet size |
| 0 1 0 0 |
16 |
|
0 1 0 1
|
32
|
|
0 1 1 0
|
64
|
|
0 1 1 1
|
128
|
|
1 0 0 0
|
256
|
|
1 1 0 1
|
512
|
|
1 1 0 0
|
1024
|
|
1 1 1 0
|
2048
|
|
1 1 1 1
|
4096
|
|
43 - Window size indication
| - Octet : |
utility code |
| bits 8-1 |
43 H |
| - Octet 1: |
utility parameter field |
| bit 8 |
0 |
| bits 7-1 |
Window size from the called STE |
| - Octet 2: |
utility parameter field |
| bits 8 |
0 |
| bits 7-1 |
Window size from the calling STE |
|
The values of window coded on bits 7-1 are binary encoded.
44 - RPOA selection
| - Octet : |
utility code |
| bits 8-1 |
44 H |
|
The parameter field contains the data network identification code DNIC
corresponding to the initial RPOA transit network requested.
| - Octet 1: |
Identification code |
| bits 8-5 |
First digit (binary coded decimal) |
| bits 4-1 |
Second digit (binary coded decimal) |
| - Octet 2: |
Identification code |
| bits 8-5 |
Third digit (binary coded decimal) |
| bits 4-1 |
Fourth digit (binary coded decimal) |
|
49 - Transit delay indication
| - Octet : |
utility code |
| bits 8-1 |
49 H |
| - Octets 1-2: |
Transit delay |
| bits 16-1 |
Number in milliseconds from bit 16 to bit 1 (binary
coded). |
|
4A - Clearing network identification code
| - Octet : |
utility code |
| bits 8-1 |
4A H |
| - Octet 1: |
Identification code |
| bits 8-5 |
First digit (binary coded decimal) |
| bits 4-1 |
Second digit (binary coded decimal) |
| - Octet 2: |
Identification code |
| bits 8-5 |
Third digit (binary coded decimal) |
| bits 4-1 |
Fourth digit (binary coded decimal) |
|
4B - Transit delay selection
| - Octet : |
utility code |
| bits 8-1 |
4B H |
| - Octets 1-2: |
Transit delay |
| bits 16-1 |
Number in milliseconds from bit 16 to bit 1 (binary coded). |
|
81 - Call identifier
| - Octet : |
utility code |
| bits 8-1 |
81 H |
| - Octets 1-3: |
Call identifier |
| bits 24-1 |
Binary data |
|
C3 - Closed user group indication
| - Octet : |
utility code |
| bits 8-1 |
C3 H |
| - Octet 1: |
Length in octets of utility parameter field |
| bits 8-1 |
0 0 0 0 0 1 0 0 = 04 H |
| - Octet 2: |
international interlock code |
| bits 8-5 |
First digit (binary coded decimal) |
| bits 4-1 |
Second digit (binary coded decimal) |
| - Octet 3: |
international interlock code |
| bits 8-5 |
Third digit (binary coded decimal) |
| bits 4-1 |
Fourth digit (binary coded decimal) |
| - Octets 4-5: |
international interlock code |
| bits 16-1 |
Remaining 16 bits of the code |
|
C7 - Closed user group with outgoing access indication
| - Octet : |
utility code |
| bits 8-1 |
C9 H |
| - Octet 1: |
Length in octets of utility parameter field |
| bits 8-1 |
0 0 0 0 0 1 0 0 = 04 H |
| - Octet 2: |
international interlock code |
| bits 8-5 |
First digit (binary coded decimal) |
| bits 4-1 |
Second digit (binary coded decimal) |
| - Octet 3: |
international interlock code |
| bits 8-5 |
Third digit (binary coded decimal) |
| bits 4-1 |
Fourth digit (binary coded decimal) |
| - Octets 4-5: |
international interlock code |
| bits 16-1 |
Remaining 16 bits of the code |
|
X75 L3 parameters: time-limit list
Time-limit T30
| T30 |
STE X/Y |
| State |
r2/r3 |
| Start |
STE X/Y issues a restart request packet |
| Stop |
STE X/Y leaves the r2/r3 state (i.e., the restart
confirmation or restart request packet is received) |
|
Time-limit T31
| T31 |
STE X/Y |
| State |
p2/p3 |
| Start |
STE X/Y issues a call request packet |
| Stop |
STE X/Y leaves the p2/p3 state (e.g., the call connected,
clear request or call request packet is received) |
|
Time-limit T32
| T32 |
STE X/Y |
| State |
d2/d3 |
| Start |
STE X/Y issues a reset request packet |
| Stop |
STE X/Y leaves the d2/d3 state (e.g., the reset confirmation
or reset request packet is received) |
|
Time-limit T33
| T33 |
STE X/Y |
| State |
p6/p7 |
| Start |
STE X/Y issues a clear request packet |
| Stop |
STE X/Y leaves the p6/p7 state (e.g., the clear
confirmation or clear request packet is received) |
|
| 
