Numbering & addressing


The International Telecommunication Union (ITU-T) has set out the principles of international public telecommunication numbering for the fixed network in their Recommendation E.164. However, the widespread use of the Internet has meant that it is becoming more and more necessary to unify the E.164 telephone numbering scheme with the addressing schemes used in the Internet.

The Internet uses the Domain Name System (DNS) to provide IP addresses, among other things. Specification RFC 3761 from the Internet Engineering Task Force (IETF) defines ENUM (Electronic Numbering) and provides a suite of protocols to enable callers or networks to determine if a called party can be contacted over the internet. ENUM facilitates the transfer of traffic from public telecommunications networks to the Internet.

RFC 3761 specifies how the DNS can be used for storage of E.164 numbers. More specifically, it shows how DNS can be used for identifying available services connected to one E.164 number.

Our Role & Activities

TC NTECH has the task of working on issues concerning Numbering, Naming, Addressing and Routeing. It is responsible for:

  • Co-ordination of the numbering and addressing issues within ETSI, and contributing to ITU-T Study Group 2
  • Addressing and Naming translation
  • Collaborating with CEPT/ECC WG NaN (Numbering and Networks)
  • Collaborating with ERO (the European Radio Office) on European numbering, naming and addressing issues


The following is a list of recently published and frequently downloaded standards. Please use the ETSI standards search to find further related standards in the public domain or to subscribe for alerts on updates of ETSI standards. 

For work in progress see the ETSI Work Programme on the Portal.

Standard No.Standard Title
EN 300 927 Digital cellular telecommunications system (Phase 2+) (GSM);
Numbering, addressing and identification
EN 300 523 Digital cellular telecommunications system (Phase 2) (GSM);
Numbering, addressing and identification
TR 102 300-5 Voice plus Data (V+D); Designers' guide;
Part 5: Guidance on numbering and addressing
EG 202 118 The structure of the TETRA numbering resource, interworking and high level policy for administration
TS 101 376-3-3 GEO-Mobile Radio Interface Specifications (Release 2) General Packet Radio Service;
Part 3: Network specifications;
Sub-part 3: Numbering, addressing and identification; GMPRS-1 03.003
TS 129 120 Universal Mobile Telecommunications System (UMTSTM);
Mobile Application Part (MAP) specification for Gateway Location Register (GLR); Stage 3
TS 129 119 Universal Mobile Telecommunications System (UMTSTM);
GPRS Tunnelling Protocol (GTP) specification for Gateway Location Register (GLR)
TS 124 030 Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTSTM);
Location Services (LCS); Supplementary service operations; Stage 3