##### Telephony service link

Service link of this type has the same parameters as the periodic service link (see Periodic service link) plus one specific parameter:

- Telephone numbers is the table with phone numbers, containing the following information on each entry:
- Login to be used for identification of the service link.

- Password to be used for the user’s registration or a call authorization.
- Incoming trunk, Outgoing trunk, PBX ID against which every call must be checked (if set).
- Telephone number issued to the user upon registration (if set).
- Allowed CID which is a regular expression to check against the Calling-Station-ID attribute of the authentication request. If the regex is set, but the attribute does not match it or is missing, the authorization is denied.

The set of parameters identifying the telephony service link (which are: login, incoming trunk, outgoing trunk, and PBX ID) must be unique. In each set at least one of these parameters must be filled, i.e. non-empty. If a call matches several service links by some parameters, the one with the greatest number of matches is selected.

Parameters of the service itself are described in Telephony service.