4.2 Number formatting

Number formatting

It is important to use correct international number formatting to avoid configuration issues during device provisioning.

E.164 is the international telephone numbering format that ensures that each device has a globally unique number. This is what allows phone calls and text messages to be correctly routed to individual phones in different countries.

E.164 numbers are formatted [+] [country code] [subscriber number including area code] and can have a maximum of fifteen digits.

Here are some examples:

  • +491522881739

  • +442079461000

  • +331990089726

Please note that

  • E.164 numbers don't contain any special characters

  • E.164 numbers don't contain the country long distance dial code (0)

The DFN configuration system and Admin Portal use a number formatting which is a derivation of the Microsoft number formatting. A further segmentation of numbers is created to define number ranges within a SIP trunk before defining what individual DDI numbers are.

For example, in a number +4420794601(00–19), the SIP trunk contains 20 individual DDI numbers (00–19).