Signalling Point Codes
Signalling point codes (SPCs) are used to address signalling points in signalling networks based on ITU‑T Signalling System No 7 (SS No 7). SPCs are valid only within a signalling network.
A distinction is made between the national signalling networks as described in ITU‑T Recommendation Q.704 and the international signalling network described in ITU‑T Recommendation Q.708.
National signalling point codes (NSPCs) (Q.704)
In Germany, national SS No 7 networks are interconnected by an intermediate signalling network. The signalling points in the intermediate network are numbered consecutively to clearly identify and address each point. The points are numbered using a 14‑bit code, hence there are 214 = 16,384 NSPCs. The 14 bits are divided into four fields with the following bits: 4‑3‑4‑3. Each field is represented by a decimal number.
National signalling point code (NSPC)
aa (00 to 15)
b (0 to 7)
cc (00 to 15)
d (0 to 7)
The codes as represented by decimal numbers range from 00‑0‑00‑0 to 15‑7‑15‑7. The SPCs 00‑0‑00‑0 and 15‑7‑15‑7 are not used, for technical and operational reasons.
The "Provisional rules for the assignment of national signalling point codes (NSPCs)" provide the legal basis for the assignment and use of NSPCs. The rules also constitute the numbering plan as defined in section 1 of the Telecommunications Numbering Ordinance (TNV).
Antrag NSPC (pdf / 42 KB) (only in German language available)
ITU‑T Recommendation Q.704 is available at www.itu.int.
International signalling point codes (ISPCs) (Q.708)
ISPCs are required by all telecommunications system operators (as defined in section 3 para 17 of the Telecommunications Act – TKG) wishing to maintain SS No 7 relations with other telecommunications system operators in the international intermediate signalling network.
Each country is assigned ISPCs in blocks of eight codes (signalling area/network codes – SANCs) by the ITU's TSB. The 14 bits are divided into three fields with the following bits: 3‑8‑3.
International signalling point code (ISPC)
|Signalling area/network code (SANC)|
|Signalling point identification|
ISPCs are assigned on an individual basis under section 66 of the Telecommunications Act, as the Bundesnetzagentur has not yet issued any relevant assignment rules nor a numbering plan.
Applications for ISPC assignment must be accompanied by proof that an ISPC is required. Applications should be sent to the following address:
Referat 118 Nummernverwaltung
Antragsformular ISPC (pdf / 118 KB) (The application is only in German language available)
ITU‑T Recommendation Q.708 and a list of the ISPCs assigned worldwide are available at www.itu.int.