The present document specifies the third version of the Integrated Services Digital Network (ISDN) - Global System for Mobile communications (GSM) Public Land Mobile Network (PLMN) signalling interface. The present document is applicable to the interconnection of PLMN and ISDN.
The ISUP interface defined is the trunk signalling interface between the PLMN and the ISDN. It is assumed that the interface between PLMN and ISDN can occur at any point in a national network, provided that the exchange in the national network has this ISDN-PLMN signalling interface. This signalling interface is based on ISUP version 3 (as given in EN 300 356-1 [1] to EN 300 356-20 [19]). The
functionality in the GSM system is based on GSM Phase 2+ Release 1998.
NOTE 1: Support of new functionality in the GSM system applicable for this interface may be included in
subsequent versions of the present document or may be published as a new EN.
Connection types:
The following ISUP version 3 connection types can be supported:
speech;
3,1kHzaudio;
64 kbit/s unrestricted;
64 kbit/s unrestricted preferred;
2× 64 kbit/s unrestricted;
384 kbit/s unrestricted;
1 536 kbit/s unrestricted;
1 920 kbit/s unrestricted.
NOTE 2: 2 × 64 kbit/s, 384 kbit/s, 1 536 kbit/s, 1 920 kbit/s unrestricted and 64 kbit/s unrestricted preferred
connection types are not supported by the GSM access, however the connection types may be used in
order to support other access methods via the GSM network.