Direct route ISDN primary route interface

A method of operating a telecommunications network, the method comprising:

• receiving a call at an originating service switching point (SSP) from a user seeking dial-up access to a data network of a computer services provider;
• at the originating SSP, generating a call routing query including a called number associated with the call;
• communicating the call routing query from the originating SSP to a signal control point (SCP) of the telecommunications network, the SCP including an associated SCP database storing data for call routing;
• at the SCP, based on the called number contained in the call routing query, identifying in the SCP database a customer for which the call is intended and a list of telephone numbers that are used for dial-up access to the customer and associated Direct Route Primary Rate Interface trunk groups coupling the originating SSP and a terminating SSP associated with the customer;
• if, based on the list in the SCP database, a Direct Route Primary Rate Interface trunk group is associated with the computer services provider, returning to the originating SSP from the SCP call routing instructions for routing the call from the originating SSP to the Direct Route Primary Rate Interface trunk group;
• and
• if a Direct Route Primary Rate Interface trunk group is associated with the computer services provider, returning to the originating SSP from the SCP call routing instructions for routing the call to the terminating SSP when traffic to the Direct Route Primary Rate Interface trunk group exceeds a capacity threshold associated with the computer services provider.