Hello David,
Maybe this would be useful. 
https://lists.kamailio.org/pipermail/sr-users/2015-November/090595.html

With best regards.Mojtaba

On Tue, 29 Jan 2019, 06:00 David Cunningham, <dcunningham@voisonics.com> wrote:
Hello,

I'm hoping someone can give advice on altering the received parameter in the Contact header on a reply. The situation is that a customer is REGISTERing using TLS, and our Kamailio replies with a 200 OK that includes a Contact header like this:

Contact: <sip:123456789@xx.xx.102.10:5061;transport=tls>;expires=3600;received="sip:xx.xx.102.10:36051;transport=TLS"

The customer's device apparently had an issue with this, and the device manufacturer advises that they need the ";transport=TLS" on the received parameter removed. This sounds like a strange requirement, but it's what we've been told. Does anyone know how to alter this in a Kamailio configuration?

Our system uses www_authorize to authenticate and is running Kamailio 4.2.1.

Thanks in advance for any help!

--
David Cunningham, Voisonics Limited
http://voisonics.com/
USA: +1 213 221 1092
New Zealand: +64 (0)28 2558 3782
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