Chapter 5. How To Configure Advanced SIP

The basic way of recognizing calls is to check the country code, which is the first part of the phone number. In the table, there are three rows for matching UK calls. The two "UK numbers 00" rows give the same result, as does the two "US numbers" rows. The 10.47.2.243 IP address is that of the Telecommuting Module itself.

The ".*" expression in the Reg Expr fields match 0 or more characters of any kind. The parantheses show how much of the incoming Request-URI we want to keep when forwarding the request.

In the Forward To table, you define where calls should be forwarded. This is used in the Dial Plan table below.

In this case, define your two SIP operators. One may use accounts and the other IP addresses for authentication.

The two "UK Operator" rows are nearly the same.

With the "UK Operator" row, the Request-URI in the incoming call will have the domain part replaced with what is entered in the Replacement URI field. The username part of the URI will be kept.

With the "UK Operator regexp" row, the Telecommuting Module will get whatever was in the first set of parantheses in the Matching Request-URI table, and use that as the user- name part. The domain part is "sipoperator.co.uk;b2bua". The ";b2bua" parameter makes the Telecommuting Module handle all REFER requests itself; instead of forwarding them. This can be useful as many operators do not support the REFER method, which is used for call transfers.

At last, you combine these definitions in the Dial Plan table.

For UK calls, the operator requires that the phone number begins with "00", which means that some calls can be forwarded directly (row 2), but for calls where the number starts with "+", this has to be replaced with "00" (row 3). This means the calls that originate from the "+ phones".

For US calls, use any of the defined US Request-URIs, and forward to the US operator.

Note that if you want to use a Reg Expr definition for Forward To, you also need to use a Reg Expr definition for the Request-URI.

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