> -        // for Reply and TCP sends from P-CSCF server port, for Reply and UDP sends from P-CSCF client port
-        src_port = dst_proto == PROTO_TCP ? s->port_ps : s->port_pc;
+        // Check send socket
+        struct socket_info * client_sock = grep_sock_info(via_host.af == AF_INET ? &ipsec_listen_addr : &ipsec_listen_addr6, src_port, dst_proto);
+        if(client_sock) {
+            // for Reply and TCP sends from P-CSCF server port, for Reply and UDP sends from P-CSCF client port
+            src_port = dst_proto == PROTO_TCP ? s->port_ps : s->port_pc;
 
-        // for Reply and TCP sends to UE client port, for Reply and UDP sends to UE server port
-        dst_port = dst_proto == PROTO_TCP ? s->port_uc : s->port_us;
+            // for Reply and TCP sends to UE client port, for Reply and UDP sends to UE server port
+            dst_port = dst_proto == PROTO_TCP ? s->port_uc : s->port_us;
+        }
+        else
+        {
+            src_port = s->port_pc;
+            dst_port = s->port_us;
+        }