HMRs are important as they provide great flexibility to modify headers, SDP, XML, etc, changes that can actually modify the routing of the sessions.

In this entry let’s create a more complex HMR making changes only if an specific contact information is validated, this can be seen that in a graphic representation:

And in a sip message:

Hands on, lets create the HMR AddHeaderIfURIUsersipp, this SIP manipulation element is divided into 2 sections:

Now lets execute 2 tests (reference to the Testing HMRs entry for manipulation in the test-sip-manipulation):

1. Matching Contact from sipp in Contact header

2. No match in Contact header