Telecommunications - Configuration of X.25 CUG

Per-call facility options - Closed User Group Selection

Per-call facility options - Closed User Group with Outgoing Access Selection

Per-call facility options - Bilateral Closed user group


Per-call facility options - Closed User Group Selection

Description of Facility

Allows the to be specified.

Basic Format:

Facility code Parameter field
03 hex CUG index BCD

| 03 | 00000011 | Closed user group selection..............#

Extended Format:

Facility code first 2 digits final digits
47 hex CUG index BCD CUG index BCD

| 47 | 01000111 | Closed user group selection.extended.....#

A closed user group ( ) permits the DTEs belonging to the closed user group to communicate with each other but precludes communication with other users.

Each member of the CUG identifies it with a local CUG ID (1-99).

UK(a) - only supports the Basic format (ie max of 99 CUGs per line).

Limitations are:

UK(b) - CUGs are supported but they may not be necessary because security can be provided by giving the user a 'profile' which defines who can access their circuit. Extended format of CUG not supported.

Extended format not supported.

+--------------------------------------------------------------------------------------------+

| X.2 LEVEL 3 PER CALL FACILITY | X.2 (1984) | UK(a) | UK(b) |interworking|

| OPTIONS | REF CLASS | now | now |R5a|R5b| R6 | |

+-------------------------------------+-------------+--------+-----+---+---+----+------------|

| Closed user group selection.........| 2.1 E |

|

|

|

|

|

|

| CUG extensions......................| | . | . | . | . | . | |

+--------------------------------------------------------------------------------------------+



Per-call facility options - Closed User Group with Outgoing Access Selection

Description of Facility

Enables a DTE to belong to one or more closed user groups and to originate calls to DTEs in the open part of the network.

Basic Format:

Facility code Parameter field
09 hex CUG index BCD

| 09 | 00001001 | Closed user group outgoing access........#

Extended Format:

Facility code first 2 digits final digits
48 hex CUG index BCD CUG index BCD

| 48 | 01001000 | Closed user group outgoing access ext....#

When the closed user group with outgoing access facility is subscribed to and the DTE has a default CUG (known as a preferential CUG) then only the closed user group selection facility is applicable for use at the interface.

When the closed user group with outgoing access facility is subscribed to and the network offers to the DTE the capability of choosing whether or not to have a preferential CUG and the DTE has no preferential CUG, then both the closed user group facility and the closed user group with outgoing access facility are applicable.

+--------------------------------------------------------------------------------------------+

| X.2 LEVEL 3 PER CALL FACILITY | X.2 (1984) | UK(a) | UK(b) |interworking|

| OPTIONS | REF CLASS | now | now |R5a|R5b| R6 | |

+-------------------------------------+-------------+--------+-----+---+---+----+------------|

| Closed user group with outgoing | | | | | | | |

| access selection....................| 2.14 A | . |

|

|

|

| |

+--------------------------------------------------------------------------------------------+

Extended format not supported.

RD 0004 part 8:1.C (PICS proforma Public Network1984)

FS4b - CUG selection with outgoing access

- basic format ........ O = Optional

FS4e - CUG selection with outgoing access

- extended format ...... P = Prohibited

FR4b - CUG selection with outgoing access

- basic format ........ O = Optional

FR4e - CUG selection with outgoing access

- extended format ...... P = Prohibited

Public Network cannot accept CUG selection with O/G access.

Implementation issues


Per-call facility options - Bilateral Closed user group

Description of Facility

Allows the selection of a Bilateral Closed user group

Facility code first 2 digits final digits
41 hex CUG index BCD CUG index BCD

| 41 | 01000001 | Bilateral Closed user group..............#

+--------------------------------------------------------------------------------------------+

| X.2 LEVEL 3 PER CALL FACILITY | X.2 (1984) | UK(a) | UK(b) |interworking|

| OPTIONS | REF CLASS | now | now |R5a|R5b| R6 | |

+-------------------------------------+-------------+--------+-----+---+---+----+------------|

| Bilateral closed user group select..| 2.2 A | . | . | . | . | . | |

+--------------------------------------------------------------------------------------------+

Not supported.

&UKa& = yUKa support

UKa release 4 does not support these facilities.


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