--- channels/chan_sip.c.jnx	2004-12-18 14:50:22.946600373 +0100
+++ channels/chan_sip.c	2004-12-18 15:25:59.659854934 +0100
@@ -190,7 +190,6 @@
 static int global_capability = AST_FORMAT_ULAW | AST_FORMAT_ALAW | AST_FORMAT_GSM | AST_FORMAT_H263;
 static int noncodeccapability = AST_RTP_DTMF;
 
-static char ourhost[256];
 static struct in_addr __ourip;
 static int ourport;
 
@@ -8433,6 +8432,53 @@
 	return peer;
 }
 
+static int find_ourip(void)
+{
+	char ourhost[256];
+	struct ast_hostent ahp;
+	struct hostent *hp;
+	struct sip_pvt *p;
+
+	/* just use the bind address if it is nonzero */
+	if (ntohl(bindaddr.sin_addr.s_addr)) {
+		memcpy(&__ourip, &bindaddr.sin_addr, sizeof(__ourip));
+		return 0;
+	}
+	/* try to use our hostname */
+	if (gethostname(ourhost, sizeof(ourhost))) {
+		ast_log(LOG_WARNING, "Unable to get hostname\n");
+	} else {
+		hp = ast_gethostbyname(ourhost, &ahp);
+		if (hp) {
+			memcpy(&__ourip, hp->h_addr, sizeof(__ourip));
+			return 0;
+		}
+	}
+	/* try to use the IP address the kernel thinks it will use to talk to the first peer */
+	ast_mutex_lock(&regl.lock);
+	if (regl.registrations) {
+		p = sip_alloc(regl.registrations->callid, NULL, 0);
+		if (!p) {
+			ast_log(LOG_WARNING, "Unable to allocate SIP\n");
+		} else {
+			if (create_addr(p, regl.registrations->hostname)) {
+				ast_log(LOG_WARNING, "Unable to create address for %s\n", regl.registrations->hostname);
+			} else {
+				if (ast_ouraddrfor(&p->sa.sin_addr, &__ourip)) {
+					ast_log(LOG_WARNING, "Unable to find our address from peer address\n");
+				} else {
+					sip_destroy(p);
+					ast_mutex_unlock(&regl.lock);
+					return 0;
+				}
+			}
+			sip_destroy(p);	
+		}
+	}
+	ast_mutex_unlock(&regl.lock);
+	return -1;
+}
+
 /*--- reload_config: Re-read SIP.conf config file ---*/
 static int reload_config(void)
 {
@@ -8451,10 +8497,6 @@
 	global_dtmfmode = SIP_DTMF_RFC2833;
 	global_promiscredir = 0;
 	
-	if (gethostname(ourhost, sizeof(ourhost))) {
-		ast_log(LOG_WARNING, "Unable to get hostname, SIP disabled\n");
-		return 0;
-	}
 	cfg = ast_load(config);
 
 	/* We *must* have a config file otherwise stop immediately */
@@ -8674,19 +8716,9 @@
 		}
 		cat = ast_category_browse(cfg, cat);
 	}
-	
-	if (ntohl(bindaddr.sin_addr.s_addr)) {
-		memcpy(&__ourip, &bindaddr.sin_addr, sizeof(__ourip));
-	} else {
-		hp = ast_gethostbyname(ourhost, &ahp);
-		if (!hp) {
-			ast_log(LOG_WARNING, "Unable to get IP address for %s, SIP disabled\n", ourhost);
-			if (!__ourip.s_addr) {
-				ast_destroy(cfg);
-				return 0;
-			}
-		} else
-			memcpy(&__ourip, hp->h_addr, sizeof(__ourip));
+	if (find_ourip()) {
+		ast_log(LOG_WARNING, "Unable to get own IP address, SIP disabled\n");
+		return 0;
 	}
 	if (!ntohs(bindaddr.sin_port))
 		bindaddr.sin_port = ntohs(DEFAULT_SIP_PORT);