I have an edge-proxy which accepts TCP
connections from clients. When I know that the clients are
behind NATs (for example), I use the set_forward_no_connect()
function to force connection reuse and avoid timeouts. In the
case where the connection has already gone, the system sends a
“477 Unfortunately error on sending to next hop occurred
(477/TM)” response back to the registrar.
These connections are using outbound, so I
would like to convert this into a “430 Flow Failed” response
to the registrar, but the 477 response doesn’t seem to trigger
the onreply_route or failure_route.
Is there a way of trapping and handling
this failure? If not, do we need more flexibility in handling
this particular tcp_send error (or other similar ones)? Other
systems may wish to try additional destinations from the
failure route.
Snippets of my cfg and logs are below. The
con_reuse flag is checked in tcp_send at tcp_main.c:1846
Regards,
Hugh
route[RELAY] {
xlog("L_INFO",
"$rm: route[RELAY]\n");
loose_route();
$var(lr_ret) = $rc;
if ($var(lr_ret) == 2) {
xlog("L_INFO",
"$rm: loose route with outbound\n");
t_on_failure("FAIL_OUTBOUND");
set_forward_no_connect();
if (t_relay() <
0) {
xlog("L_WARN", "$rm: loose route with outbound
failed\n");
sl_send_reply("500", "Something bad happened");
}
exit;
}
. . .
}
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: Routing logic starts here
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: route[REQINIT]
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: route[INITIAL_REQUEST]
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: route[RECORD_ROUTE]
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: route[RELAY]
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: INVITE: loose route with outbound
May 1 17:01:08 kamailio-cep[28226]: ERROR:
tm [../../forward.h:219]: msg_send(): msg_send: ERROR:
tcp_send failed
May 1 17:01:08 kamailio-cep[28226]: ERROR:
tm [t_fwd.c:1609]: t_send_branch(): ERROR: t_send_branch:
sending request on branch 0 failed
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: ACK: Routing logic starts here
May 1 17:01:08 kamailio-cep[28226]: INFO:
<script>: ACK: route[REQINIT]