Subsystem Number - GSM and UMTS SSNs

GSM and UMTS SSNs

In Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS), subsystem numbers may be used between Public land mobile networks (PLMNs), in which case they are taken from the globally standardized range (1 - 31) or the part of the national network range (129 - 150) reserved for GSM/UMTS use between PLMNs. For use within a PLMN, numbers are taken from the part of the national network range (32 - 128 & 151 - 254) not reserved for GSM/UMTS use between PLMNs.

The following globally standardised subsystem numbers have been allocated for use by GSM/UMTS:

0 Not used/Unknown 1 SCCP MG 6 HLR (MAP) 7 VLR (MAP) 8 MSC (MAP) 9 EIR (MAP) 10 is allocated for evolution (possible Authentication Centre).

The following national network subsystem numbers have been allocated for use within GSM/UMTS networks:

249 PCAP 250 BSC (BSSAP-LE) 251 MSC (BSSAP-LE) 252 SMLC (BSSAP-LE) 253 BSS O&M (A interface) 254 (A interface)

The following national network subsystem numbers have been allocated for use within and between GSM/UMTS networks:

142 RANAP 143 RNSAP 145 GMLC (MAP) 146 CAP 147 gsmSCF (MAP) or IM-SSF (MAP) 148 SIWF (MAP) 149 SGSN (MAP) 150 GGSN (MAP)