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 Projects and Studies
Issues associated with the implementation of ITU-T Recommendation E.353 (Routing of calls when issuing International Routing Addresses) in public networks
For further information please contact:

Peter Stollenmayer
Project Supervisor
Wieblinger Weg 19/4
69123 Heidelberg, Germany

Project Information
What was this Project about?

The ITU proposal was to separate customer naming from addressing of network elements for routing purposes. The basis for this is draft ITU-T Recommendation E.353. Today E.164 numbers are used for both: naming and routing. Any change to the use of E.164 numbers as routeing numbers will incur costs, and therefore needs to be justified against predetermined but not yet defined criteria. The impacts on the signalling, routeing, billing & accounting, interconnection, number portability and network boundaries has been investigated.

The possibility of different steps of implementation has been investigated, for example: global services, global networks, international numbers, ETNS, national geographic numbers.

The overall question was:
"What are the issues that would exist in changing from ITU E.164 routing numbers to ITU E.353 International Network Routing Addresses (INRA), and do these issues justify such a change?"

What were the main objectives of this Study?

  • Identify the issues of implementing ITU E.353
  • Develop the criteria to assess these issues
  • Assess the issues as to whether a change from E.164 routing numbers to E.353 routing addresses could be justified
  • Analyse the issues for network operators by using INRAs in respect to flexible routing mechanism
Project Results