SIP Provider Deutsche Telekom, Call & Surf Connection(DE) (kb4557)

The information in this article applies to:

  • SwyxWare 2015
  • SwyxWare 2013

[ Summary | Information | Links ]


Information und configuration hints for SIP provider Deutsche Telekom, Call & Surf Connection (Germany).


General information

The Deutsche Telekom is offering the possibility to perform telephony on a SIP base to their private customers, when using their Call & Surf connections. This is not a traditional SIP trunk, but nevertheless the SwyxWare can be configured accordingly use this connection for telephony.
This can only be used when it is combined with internet access from Deutsche Telekom, it cannot be used an any other internet connection.

Currently, for a reliable operation of a SwyxWare on a Call & Surf connection, at least SwyxWare2015R with a CHF has to be installed. 


Required information:

  • Access number (previously T-Online Number) or its alias, i.e. 11223344
  • Personal password for the Telekom Call & Surf connection
  • assigned numbers (usually threei), i.e.. 040112233, 04011223334, 040112235

These information is provided by Deutsche Telekom when the connection is created or can be accessed through the Telekom customer center.

For each single assigned number, a dedicated SIP trunk group must be created. When configuring the user data for each SIP trunk, the associated public number must be entered as User ID in format canonical with plus, i.e. +4940112233. The Access number or its alias must be extended by '' and entered as User Name, i.e. In order to enable forwarding of inbound external calls to another external destination, the number of simultanous call on each trunk must at least be '2'.

After the public calling number was assigned to a user, the exclusive usage of this trunk for that specific user must be configured through the routing records of the SIP trunk.

If an external, inbound call needs to be forwarded to another external destination, it is necessary to signal the public number of the forwarding party. This has to be configured in the tab 'NUmber signaling' of the trunk properties (Use: Originator's number, if assigned to this trunk, otherwise: Number of the transferor.)

For your convenience the generated CustomProviderProfiles.config is available for download at the end of this article. Extended information about how to use this file can be found at Configuration and Adaptation of SIP Providers via Provider Profiles (kb3436).

Important: From SwyxWare2013 R4 on, the provider profile for Telekom Call & Surf is already available in the list of provider profiles and the CustomProviderProfiles.config is no longer necessary.
Tested Features
  • Incoming/outgoing national calls
  • Incoming/outgoing international calls
  • Correct Calling Line Identificaion (CLI) on national and international calls
  • Holding and retrieving calls
  • Toggeling between two calls
  • Call transfer
  • Conferencing
  • Mutually supported codec:
    • G.711a
  • Incoming/outgoing DTMF signaling in accordance with via RFC2833


  • CLIP No Screening is not supported
  • FAX transmission via T38 is not supported

Test date:
10/12/2013 with SwyxWare2013 R3
08/01/2015 with SwyxWare2015
28/04/2015 with SwyxWare2015 R2 with CHF

Overview of tested SIP provider


As far as software supplied or used by us, includes open source elements the additional terms under apply in addition. An overview which products from the Swyx portfolio include open source elements and which open source license is relevant can be found under

The third-party contact information included in this article is provided to help you find the technical support you need. This contact information is subject to change without notice. Swyx in no way guarantees the accuracy of this third-party contact information nor is responsible for it's content.


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