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If anyone with an IPO configured with SIP trunks is suddenly having problems with calls being denied, but their trunks are registered listen up. Skip to the fix at the bottom if you don't want to read the background.
The SIP carrier for many of my clients had multiple IPOs stop accepting calls last night 10/25/2010. When a call was routed to go directly to an AA the IPO would receive the Invite wait roughly 5-7 seconds before responding with a "100 trying" message. This was tripping a timer on the carrier causing them to cancel the call. If routing to a phone/HG the IPO would receive an invite initiate ringing and then it seems when the call was answered by VM or a person it would send a 503 to the carrier dropping the call.
After some troubleshooting it appears that the STUN server address preconfigured in the IPO (69.90.168.13) is accepting connections. However it is not responding to any requests other than allowing the IPO to initiate a client connection. I'm not sure if it is even a STUN server to begin with or if its just a firewall/server accepting that particular port. Either way it is not working and causing problems.
The IPO would receive the invite, initiate a connection to the STUN address and attempt to resolve IP/port for traversal of media through NAT. It does not receive a response from the server and attempts for roughly 5 seconds. This is causing the long delay for the "100 Trying" message when going to AA. This also is the cause for the system to send a "503 unavailable" when a person answers the phone. You can verify if this is your problem by turning on the STUN filter in your monitor.
The Fix: Open Manager and IPO > Lines > {select your sip trunk/s} > change "Use Network Topology Info" from LAN1 / LAN2 to None.
The carrier we use runs a SBC (Session Border Controller) so there is no need for STUN. I believe most carriers are running SBCs now anyway.
Hopefully this helps anyone banging their head against the wall.
Chris
ACA- Implement IP Office
The SIP carrier for many of my clients had multiple IPOs stop accepting calls last night 10/25/2010. When a call was routed to go directly to an AA the IPO would receive the Invite wait roughly 5-7 seconds before responding with a "100 trying" message. This was tripping a timer on the carrier causing them to cancel the call. If routing to a phone/HG the IPO would receive an invite initiate ringing and then it seems when the call was answered by VM or a person it would send a 503 to the carrier dropping the call.
After some troubleshooting it appears that the STUN server address preconfigured in the IPO (69.90.168.13) is accepting connections. However it is not responding to any requests other than allowing the IPO to initiate a client connection. I'm not sure if it is even a STUN server to begin with or if its just a firewall/server accepting that particular port. Either way it is not working and causing problems.
The IPO would receive the invite, initiate a connection to the STUN address and attempt to resolve IP/port for traversal of media through NAT. It does not receive a response from the server and attempts for roughly 5 seconds. This is causing the long delay for the "100 Trying" message when going to AA. This also is the cause for the system to send a "503 unavailable" when a person answers the phone. You can verify if this is your problem by turning on the STUN filter in your monitor.
The Fix: Open Manager and IPO > Lines > {select your sip trunk/s} > change "Use Network Topology Info" from LAN1 / LAN2 to None.
The carrier we use runs a SBC (Session Border Controller) so there is no need for STUN. I believe most carriers are running SBCs now anyway.
Hopefully this helps anyone banging their head against the wall.
Chris
ACA- Implement IP Office
