I have a Mitel HX 5000 controller and a Mivoice Border Gateway system setup in gateway mode in DMZ.
I have a Spectralink 8440 SIP phone that works perfectly when used locally connected directly to the HX 5000 controller. I have setup an SIP account on the border gateway to be used by this phone. When going through the border gateway, the phone registers correctly and is able to communicate with other extensions on the 5000 just fine when calling IN from the Spectralink. The audio is two-way and everything seems great, but when someone tries to dial the extension of the spectralink, the invite is sent to the border gateway but it gives back an "unknown user" response (the mitel sees a 404 not found message in the SIP output).
The phone appears connected and as I mentioned can be called from just fine (the spectralink is extension 235 in this case). Anyone else dialing 235 gets the error as mentioned.
This is from the tug log on the MBG:
2015-08-12 10:34:46.179807000 15 (25.86) SipUA: RX <<< INVITE request requri=sip:235@192.168.100.93:5060 from=sip:138@192.168.100.111:5060 to=sip:235@192.168.100.93:5060 callid=445841497-968 cseq=1, peer addr=192.168.100.111:5060
2015-08-12 10:34:46.179842000 15
2015-08-12 10:34:46.179842000 15 (25.86) SDP: SID=1088806560 Vers=0 c=192.168.100.111
2015-08-12 10:34:46.179842000 15 m0 audio 6102 a=sendrecv pt=0 8 101 ptime=20
2015-08-12 10:34:46.179842000 15 PT:0 PCMU/8000
2015-08-12 10:34:46.179842000 15 PT:8 PCMA/8000
2015-08-12 10:34:46.179842000 15 PT:101 telephone-event/8000 fmtp: 0-15
2015-08-12 10:34:46.179842000 15
2015-08-12 10:34:46.180087000 15
2015-08-12 10:34:46.180087000 15 (25.86) SipUA: TX >>> INVITE (100) response from=sip:138@192.168.100.111:5060 to=sip:235@192.168.100.93:5060 callid=445841497-968 cseq=1, tx to=192.168.100.111:5060
2015-08-12 10:34:46.180512000 15 DLG 8 SipDialog::SipDialog( 445841497-968, sip:235@192.168.100.93:5060;tag=none, sip:138@192.168.100.111:5060;tag=Mitel-5000_445845575-968, INVITE )
2015-08-12 10:34:46.180580000 15 DLG 8 SessionState: NoSession --> OfferReceived
2015-08-12 10:34:46.181705000 15
2015-08-12 10:34:46.181705000 15 (25.86) SipUA: Invite rejected: unknown user (235)
2015-08-12 10:34:46.182004000 15 DLG 8 SessionState: OfferReceived --> OfferRejected
2015-08-12 10:34:46.182019000 15 DLG 8 DialogState: New --> Terminated
2015-08-12 10:34:46.182031000 15 DLG 8 SessionState: OfferRejected --> Completed
2015-08-12 10:34:46.182357000 15
