Other codes

Signalling point codes

Signalling point codes are used to identify the nodes in Signalling System No. 7. To avoid situations where two different nodes in a signalling network have the same signalling point code, each telecommunications operator shall use a certain range of signalling point codes assigned to it in advance. The nodes in the national signalling network are identified with national signalling point codes and the nodes in the international signalling network with international signalling point codes. The messages in the national and international network are discriminated from each other by a network indicator included in the address field.

CUG codes

In the Closed User Group (CUG) supplementary service, a CUG interlock code is used to control that users belong to a certain closed user group. The interlock code is transferred over the telecommunication network in the signalling between switching centres (SS No.7 TUP/ISUP). To avoid situations where two subscribers that belong to different user groups have the same interlock code in different operators' areas, each telecommunications operator is assigned a specific code range. The telecommunications operator may allocate interlock codes to closed user groups only from the code range assigned to it.

Centrex codes

The Centrex service may be implemented in several operators' areas provided that CTX data is transferred in SS No. 7. This CTX data includes, for instance, a group code that identifies a certain CTX group. In order for the Centrex service to be able to function between different telecommunications operators, the Centrex group codes must not overlap. Therefore, a specific range is reserved for each operator within which the operator may itself specify the group codes.

For further information on the codes described above and other codes, please contact Mr Timo Leppinen. The e-mail address is in the format firstname.surname(at)ficora.fi.