Index: chan_sip.c
===================================================================
--- chan_sip.c	(revision 174217)
+++ chan_sip.c	(working copy)
@@ -8485,13 +8485,35 @@
 		   contact info */
 		char tmp[256];
 
+	/*Check here whether it is registration query*/
+		if((p->method == SIP_REGISTER)&& get_header(req, "Contact")== "" ){
+				int expiry;
+				struct sip_peer *peer = find_peer(p->exten,NULL,TRUE,FINDALLDEVICES,TRUE);
+				if(peer){
+					if(peer->fullcontact){
+						if (peer->expire >-1 ){
+								expiry = ast_sched_when(sched, peer->expire);
+							snprintf(tmp, sizeof(tmp), "<%s:%s@%s:%d>;%d", "sip", peer->username, ast_inet_ntoa(peer->addr.sin_addr), ntohs(peer->addr.sin_port), expiry);
+							add_header(resp, "Contact",tmp);
+					}
+				}
+			
+			unref_peer(peer, "create_addr: unref peer from find_peer hashtab lookup");
+			}
+		}else{
-			snprintf(tmp, sizeof(tmp), "%d", p->expiry);
-			add_header(resp, "Expires", tmp);
 			if (p->expiry) {	/* Only add contact if we have an expiry time */
+				if(p->our_contact){
 					char contact[SIPBUFSIZE];
 					snprintf(contact, sizeof(contact), "%s;expires=%d", p->our_contact, p->expiry);
 					add_header(resp, "Contact", contact);	/* Not when we unregister */
+				}
+				snprintf(tmp, sizeof(tmp), "%d", p->expiry);
+				add_header(resp, "Expires", tmp);
			}
+		}
+	} else if (msg[0] != '4' && !ast_strlen_zero(p->our_contact)) {
 	} else if (!ast_strlen_zero(p->our_contact) && resp_needs_contact(msg, p->method)) {
 		add_header(resp, "Contact", p->our_contact);
 	}