Thanks, I was able to achieve it with below steps. $var(contact) = $sel(contact.uri); $var(alias) = $(var(contact){uri.param,alias}); $var(alias) = ";alias=" + $var(alias); replace_all($var(alias), ""); thanks, raj From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Federico Cabiddu Sent: Friday, May 17, 2019 4:27 PM To: Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; Subject: Re: [SR-Users] Rewrite contact header Hi, you can try https://kamailio.org/docs/modules/5.2.x/modules/textopsx.html#textopsx.f.re… Cheers, Federico On Fri, May 17, 2019 at 12:45 PM R, Rajkumar (Raj) <rajkumaradass@avaya.com<mailto:rajkumaradass@avaya.com>> wrote: Hello, We are using alias routing from NATHelper module and I’ve a case where the alias part ’alias=ip~port~transport’ needs to be removed from the contact header in 2xx message. There’s contact header reference “$ct” pseudo variable but it is read only. Is there any approach available to achieve this as I haven’t found anything in the forum archive search so far. thanks, raj _______________________________________________ Kamailio (SER) - Users Mailing List sr-users@lists.kamailio.org<mailto:sr-users@lists.kamailio.org> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users<https://url…