Hello community,

We made some modifications to Kamailio PCSCF sample cfg file, so when PCSCF receiving an tcp SUBSCRIBE message it add ;transport=tcp to the end of Contact URI. Below is what we added the route block right after if (is_method("INVITE|SUBSCRIBE”)) logic

         if (is_method("SUBSCRIBE") && proto=='tcp') {

            $var(original_contact_header) = $ct;

            $var(new_contact_header) = $(var(original_contact_header){re.subst,/(.*:.*)(>);/\1;transport=tcp>/g});

            remove_hf("Contact");

            append_hf("Contact: $var(new_contact_header)\r\n");

            msg_apply_changes();

         }

We did see the ;transport=tcp been added but we also seeing a bad line ;alias=[…] is added before the To: line

Does anyone know what function might cause this ;alias been added before To: line?

BR,

Weiqi