[VoiceOps] Help Requested: E.123 Intl Formatting in Google libphonenumber

Peter Beckman beckman at angryox.com
Sat Mar 5 17:08:55 EST 2022

Please post your support by adding a comment here:


On Thu, 3 Mar 2022, Henning Westerholt wrote:

> as usual the problem with standards is that there are many of them.
> I can not comment about other countries, but even in Germany it's a bit messier as you described.
> Most people in the telco world use E.164 or E.123 type for formatting to represent phone numbers.
> But many normal businesses use the national standard "DIN 5008". This
> extends E.123 with the usage of a dash to separate local extensions in
> international format, e.g.:
> +49 123 123456-123
> Many people recommend this format if the company is doing business mainly
> national, and E.123 if the company is doing business international.

  I don't see a problem here.

  DIN 5008 is a German standard, which would be considered a National
  Format. I would fully support Google's libphonenumber of using such a
  standard for formatting National Numbers for Germany in that manner.
  However, it does NOT use this standard for National formatting.

  However, for people outside of Germany who want to write out its phone
  numbers, ITU E.123 standard for International Format should be followed.

     National: +49 123 123456-123
     International: +49 123 123456 ext. 123

  libphonenumber is NOT using DIN 5008 for National:

 	<!-- Due to the high complexity of ranges in the German numbering scheme, the regular
          expressions here have been automatically simplified to reduce size. This means that
          in some cases there may be false positives (especially in fixed line ranges), but since
          German ranges differ so much by length anyway, false positives are already common. -->

  The Zoo Duisberg is at +4920360444250. Libphonenumber outputs expected

     - National Format: 0203 60444250
     - International Format: +49 203 60444250

  With extension:

     - National: 0203 60444250 ext. 134
     - International: +49 203 60444250 ext. 134

  Maybe you want to submit a request to Google's Libphonenumber to follow
  DIN 5008 for National! I would comment in support! I would be annoyed if
  libphonenumber did not follow my national standard.

Peter Beckman                                                  Internet Guy
beckman at angryox.com                                https://www.angryox.com/

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