Issue setting up New Skyetel Trunk to UCM PBX


I am trying to setup a Skytel Peer SIP Trunk to a UCM. When I call a DID on the trunk the call fails. I do a Ethernet capture during a call and the UCM rejects the call with a SIP status 404.

I am not sure if the UCM is having an issue with the local LAN IP vs the WAN IP the trunk is sending the call to?

Any help would be appreciated.

Here is what i captured being sent back to the trunk to reject the call:

Frame 43: 781 bytes on wire (6248 bits), 781 bytes captured (6248 bits)
Ethernet II, Src: Grandstr_9e:ba:60 (00:0b:82:9e:ba:60), Dst: Dell_f9:ea:90 (84:8f:69:f9:ea:90)
Internet Protocol Version 4, Src:, Dst:
User Datagram Protocol, Src Port: 5060, Dst Port: 5060
Session Initiation Protocol (404)
Status-Line: SIP/2.0 404 Not Found
Status-Code: 404
[Resent Packet: False]
[Request Frame: 42]
[Response Time (ms): 7]
Message Header
Via: SIP/2.0/UDP;received=;branch=z9hG4bK5d6a.98999fee5d7819cfb4b4a77d98a6b4e6.1
Transport: UDP
Sent-by Address:
Sent-by port: 5060
Branch: z9hG4bK5d6a.98999fee5d7819cfb4b4a77d98a6b4e6.1
Via: SIP/2.0/UDP;branch=z9hG4bKsr-xL6MWFNVRAQUfgpsa7hVR7RYW7kVRcMby7xCa7piUIsQ8.60y0ebldX7uG91ydqoa.eWRGqAyGIFl7p9lcMYa0RLyd87RM**
Transport: UDP
Sent-by Address:
Branch: z9hG4bKsr-xL6MWFNVRAQUfgpsa7hVR7RYW7kVRcMby7xCa7piUIsQ8.60y0ebldX7uG91ydqoa.eWRGqAyGIFl7p9lcMYa0RLyd87RM**
Record-Route: sip:;lr;ftag=gK0832d255;did=99d.3f8;vsf=U2s0M0JsdTNiZ2Z1ZzN1ODU3bVNtNixZZ3UxYlU-;vst=U2s0M0JsdTNiZ2Z1ZzN1ODUwbU9xPDNGb28uZ1Bf
Record-Route URI: sip:;lr;ftag=gK0832d255;did=99d.3f8;vsf=U2s0M0JsdTNiZ2Z1ZzN1ODU3bVNtNixZZ3UxYlU-;vst=U2s0M0JsdTNiZ2Z1ZzN1ODUwbU9xPDNGb28uZ1Bf
Record-Route Host Part:
Record-Route URI parameter: lr
Record-Route URI parameter: ftag=gK0832d255
Record-Route URI parameter: did=99d.3f8
Record-Route URI parameter: vsf=U2s0M0JsdTNiZ2Z1ZzN1ODU3bVNtNixZZ3UxYlU-
Record-Route URI parameter: vst=U2s0M0JsdTNiZ2Z1ZzN1ODUwbU9xPDNGb28uZ1Bf
Call-ID: !!:RcRKRGMXR7p-R6jYR7kKaFxXaFqpa7hVR7RYW7kVRcMb
[Call-ID: !!:RcRKRGMXR7p-R6jYR7kKaFxXaFqpa7hVR7RYW7kVRcMb]
From: “CID” sip:+1Calling.Number@;tag=gK0832d255
SIP Display info: “CID”
SIP from address: sip:+1Calling.Number@
SIP from address User Part: +1Calling.Number
E.164 number (MSISDN): 1Calling.Number
Country Code: Americas (1)
SIP from address Host Part:
SIP from tag: gK0832d255
To: sip:+1My.DID@UCM.WAN.IP;tag=z9hG4bK5d6a.98999fee5d7819cfb4b4a77d98a6b4e6.1
SIP to address: sip:+1My.DID@UCM.WAN.IP
SIP to address User Part: +1My.DID
E.164 number (MSISDN): 1My.DID
Country Code: Americas (1)
SIP to address Host Part: WAN.IP
SIP to tag: z9hG4bK5d6a.98999fee5d7819cfb4b4a77d98a6b4e6.1
CSeq: 870142 INVITE
Sequence Number: 870142
Method: INVITE
Server: Grandstream UCM6202V1.3A
Content-Length: 0


404 is a not found. As the UCM is responding, it is not an IP issue. It sees thye INVITE, but -

This is usually because the UCM cannot find or match the DID as contained in your inbound route to that which is being sent by Skyetel. The DID being sent must match exactly and you have to tell the UCM in which field to expect the DID from the provider. It may also be that your route is incomplete and does not contain a valid destination. Please insure that it does have a proper destination set.

In NA, most providers will send the DID in the following format:

(the “+” is a e.164 format along with 1, area code, exchange and local 4 digit number. It is like dialing long distance in the US using the 1.

Put all 3 formats using your DID in the same inbound route rule and then try. If this does not work, then go to the VoIP Trunk, Advanced settings and toggle the DID mode:

If you get to work, then you can go back, if you want to, and delete the DID numbers one at a time until it quits working and then you will know which format your provider is using.

Of course, if you can read wireshark, you can get the info from there as well without all the process of elimination as it will show the format as well as the field.