diff -NaurbB old/chan_sip.c new/chan_sip.c
--- old/chan_sip.c	2008-09-06 21:21:51.000000000 +0100
+++ new/chan_sip.c	2009-01-07 17:31:46.000000000 +0000
@@ -1542,7 +1542,8 @@
 	enum sip_transport transport;
 	int portno;			/*!<  Optional port override */
 	int expire;			/*!< Sched ID of expiration */
-	int expiry;			/*!< Value to use for the Expires header */
+	int expiryrequest;	/*!< Value to use for the Expires header */
+	int expiry;			/*!< Value of Expires header accepted by registrar */
 	int regattempts;		/*!< Number of attempts (since the last success) */
 	int timeout; 			/*!< sched id of sip_reg_timeout */
 	int refresh;			/*!< How often to refresh */
@@ -6084,12 +6085,26 @@
 	char *username = NULL;
 	char *hostname=NULL, *secret=NULL, *authuser=NULL;
 	char *callback=NULL;
+	char *expiryrequest=NULL;
 
 	if (!value)
 		return -1;
 
 	ast_copy_string(buf, value, sizeof(buf));
 
+	/* split off [/contact][~expiry] before using sip_parse_host function */
+
+	expiryrequest = strrchr(buf, '~');
+	if (expiryrequest) {
+	*expiryrequest++ = '\0';
+	}
+
+	callback = strchr(buf, '/');
+	if (callback)
+		*callback++ = '\0';
+	if (ast_strlen_zero(callback))
+		callback = "s";
+
 	sip_parse_host(buf, lineno, &username, &portnum, &transport);
 
 	/* First split around the last '@' then parse the two components. */
@@ -6108,12 +6123,7 @@
 		if (authuser)
 			*authuser++ = '\0';
 	}
-	/* split host[:port][/contact] */
-	callback = strchr(hostname, '/');
-	if (callback)
-		*callback++ = '\0';
-	if (ast_strlen_zero(callback))
-		callback = "s";
+
 	if (!(reg = ast_calloc(1, sizeof(*reg)))) {
 		ast_log(LOG_ERROR, "Out of memory. Can't allocate SIP registry entry\n");
 		return -1;
@@ -6138,9 +6148,26 @@
 		ast_string_field_set(reg, secret, secret);
 	reg->transport = transport;
 	reg->expire = -1;
-	reg->expiry = default_expiry;
+
+	reg->expiryrequest = default_expiry;
+ 	if (expiryrequest)
+ 		reg->expiryrequest = atoi(expiryrequest);
+ 	if (reg->expiryrequest < 1) {
+		ast_log(LOG_WARNING, "Invalid expiry value. Setting to %d\n", default_expiry);
+ 		reg->expiryrequest = default_expiry;
+	}
+ 	if (reg->expiryrequest < min_expiry) {
+		ast_log(LOG_WARNING, "Expiry value less than minexpiry value. (To permit this expiry value set global minexpiry=%d in sip.conf.) Setting to %d\n", reg->expiryrequest, default_expiry);
+ 		reg->expiryrequest = default_expiry;
+	}
+ 	if (reg->expiryrequest > max_expiry) {
+		ast_log(LOG_WARNING, "Expiry value greater than maxexpiry value. (To permit this expiry value set global maxexpiry=%d in sip.conf.) Setting to %d\n", reg->expiryrequest, default_expiry);
+ 		reg->expiryrequest = default_expiry;
+	}
+	reg->expiry = reg->expiryrequest;
+ 	reg->refresh = reg->expiry;
+
 	reg->timeout =  -1;
-	reg->refresh = default_expiry;
 	reg->portno = portnum;
 	reg->callid_valid = FALSE;
 	reg->ocseq = INITIAL_CSEQ;
@@ -9454,7 +9481,7 @@
 	
 	}
 
-	snprintf(tmp, sizeof(tmp), "%d", r->expiry);
+	snprintf(tmp, sizeof(tmp), "%d", r->expiryrequest);
 	add_header(&req, "Expires", tmp);
 	add_header(&req, "Contact", p->our_contact);
 	add_header(&req, "Event", "registration");
@@ -15110,7 +15137,7 @@
 		}
 		if (r->expiry > max_expiry) {
 			ast_log(LOG_WARNING, "Required expiration time from %s@%s is too high, giving up\n", p->registry->username, p->registry->hostname);
-			r->expiry = default_expiry;
+			r->expiry = r->expiryrequest;
 			r->regstate = REG_STATE_REJECTED;
 		} else {
 			r->regstate = REG_STATE_UNREGISTERED;