*** 344,349 ****
--- 344,350 ----
        int network_port;
        int cd = 0;
        const char *call_id = NULL;
+       char *force_user;

        /* all callers must confirm that sip, sip->sip_request and sip->sip_contact are not NULL */
        switch_assert(sip != NULL && sip->sip_contact != NULL && sip->sip_request != NULL);
***************
*** 419,424 ****
--- 420,433 ----
                        char *exp_var;

                        register_gateway = switch_event_get_header(*v_event, "sip-register-gateway");
+
+                       /* Allow us to force the SIP user to be something specific - needed if
+                        * we - for example - want to be able to ensure that the username a UA can
+                        * be contacted at is the same one that they used for authentication.
+                        */
+                       if ((force_user = switch_event_get_header(*v_event, "sip-force-user"))) {
+                               to_user = force_user;
+                       }

                        if ((v_contact_str = switch_event_get_header(*v_event, "sip-force-contact"))) {
                                if (!strcasecmp(v_contact_str, "nat-connectile-dysfunction") || !strcasecmp(v_contact_str, "NDLB-connectile-dysfunction")) {