--- channels/chan_sip.c	(Asterisk 13.18.3)
+++ channels/chan_sip.c	(working copy)
@@ -34114,26 +34114,30 @@ static int peer_ipcmp_cb_full(void *obj,
 
 	if (ast_sockaddr_cmp_addr(&peer->addr, &peer2->addr)) {
 		/* IP doesn't match */
 		return 0;
 	}
 
+	if (ast_sockaddr_port(&peer->addr) != ast_sockaddr_port(&peer2->addr)) {
+		/* IP matches but port doesn't match */
+		return 0;
+	}
+
 	/* We matched the IP, check to see if we need to match by port as well. */
 	if ((peer->transports & peer2->transports) & (AST_TRANSPORT_TLS | AST_TRANSPORT_TCP)) {
 		/* peer matching on port is not possible with TCP/TLS */
 		return CMP_MATCH | CMP_STOP;
 	} else if (ast_test_flag(&peer2->flags[0], SIP_INSECURE_PORT)) {
 		/* We are allowing match without port for peers configured that
 		 * way in this pass through the peers. */
 		return ast_test_flag(&peer->flags[0], SIP_INSECURE_PORT) ?
 				(CMP_MATCH | CMP_STOP) : 0;
 	}
 
-	/* Now only return a match if the port matches, as well. */
-	return ast_sockaddr_port(&peer->addr) == ast_sockaddr_port(&peer2->addr) ?
-			(CMP_MATCH | CMP_STOP) : 0;
+	/* Port matches */
+	return (CMP_MATCH | CMP_STOP);
 }
 
 static int peer_ipcmp_cb(void *obj, void *arg, int flags)
 {
 	return peer_ipcmp_cb_full(obj, arg, NULL, flags);
 }