"The best business telephones in the world."

Running out of ideas on what to check to fix this.

Have a problem where I can't make an external call on the M85 with a M700 Multicell setup. I can receive external calls though. This is part of a 3CX system.

The odd part is if I register the handset with an extension that already has a desk phone tied to it, I can call out. I've attached the SIP log below.

Sent to udp:10.1.10.10:5060 at 14/11/2017 16:21:47  (967 bytes)

INVITE sip:612****@10.1.10.10:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 10.1.10.52:5060;rport;branch=z9hG4bKvltayqpo9kf2
Max-Forwards: 70
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
To: <sip:612****@10.1.10.10:5060;user=phone>
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31264 INVITE
Contact: <sip:111@10.1.10.52;line=6845>
Allow: INVITE, CANCEL, BYE, ACK, REGISTER, OPTIONS, REFER, SUBSCRIBE, NOTIFY, MESSAGE, INFO, PRACK, UPDATE
Content-Disposition: session
Min-SE: 90
Session-Expires: 3600
Supported: replaces,100rel,timer
User-Agent: snomM700/03.55.0025 (MAC=000413611822; SER= 00000; HW=255)
Content-Type: application/sdp
Content-Length: 277

v=0
o=111 491 491 IN IP4 10.1.10.55
s=-
c=IN IP4 10.1.10.55
t=0 0
m=audio 50016 RTP/AVP 0 8 9 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:9 G722/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:20
a=maxptime:80
a=sendrecv
a=rtcp:50017

Received from udp:10.1.10.10:5060 at 14/11/2017 16:21:47  (497 bytes)

SIP/2.0 407 Proxy Authentication Required
Via: SIP/2.0/UDP 10.1.10.52:5060;rport=5060;branch=z9hG4bKvltayqpo9kf2
Proxy-Authenticate: Digest nonce="414d53595a0b5da859:ee1b13f7cf3a5e619ded4db1feca3237",algorithm=MD5,realm="3CXPhoneSystem"
To: <sip:612****@10.1.10.10:5060;user=phone>;tag=24bd086e
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31264 INVITE
User-Agent: 3CXPhoneSystem 15.5.3849.1 (3849)
Content-Length: 0



Sent to udp:10.1.10.10:5060 at 14/11/2017 16:21:47  (416 bytes)

ACK sip:612****@10.1.10.10:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 10.1.10.52:5060;rport;branch=z9hG4bKvltayqpo9kf2
Max-Forwards: 70
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
To: <sip:612****@10.1.10.10:5060;user=phone>;tag=24bd086e
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31264 ACK
User-Agent: snomM700/03.55.0025 (MAC=000413611822; SER= 00000; HW=255)
Content-Length: 0



Sent to udp:10.1.10.10:5060 at 14/11/2017 16:21:47  (1216 bytes)

INVITE sip:612****@10.1.10.10:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 10.1.10.52:5060;rport;branch=z9hG4bKd.6dsp0xvgtelm.q8y6jz0nfvf
Max-Forwards: 70
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
To: <sip:612****@10.1.10.10:5060;user=phone>
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31265 INVITE
Contact: <sip:111@10.1.10.52;line=6845>
Allow: INVITE, CANCEL, BYE, ACK, REGISTER, OPTIONS, REFER, SUBSCRIBE, NOTIFY, MESSAGE, INFO, PRACK, UPDATE
Content-Disposition: session
Min-SE: 90
Proxy-Authorization: Digest username="111", realm="3CXPhoneSystem", nonce="414d53595a0b5da859:ee1b13f7cf3a5e619ded4db1feca3237", uri="sip:612****@10.1.10.10:5060;user=phone", response="4a7a39247932c1b85f04ea8cbab03d80", algorithm=MD5
Session-Expires: 3600
Supported: replaces,100rel,timer
User-Agent: snomM700/03.55.0025 (MAC=000413611822; SER= 00000; HW=255)
Content-Type: application/sdp
Content-Length: 277

v=0
o=111 491 491 IN IP4 10.1.10.55
s=-
c=IN IP4 10.1.10.55
t=0 0
m=audio 50016 RTP/AVP 0 8 9 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:9 G722/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:20
a=maxptime:80
a=sendrecv
a=rtcp:50017

Received from udp:10.1.10.10:5060 at 14/11/2017 16:21:48  (303 bytes)

SIP/2.0 100 Trying
Via: SIP/2.0/UDP 10.1.10.52:5060;rport=5060;branch=z9hG4bKd.6dsp0xvgtelm.q8y6jz0nfvf
To: <sip:612****@10.1.10.10:5060;user=phone>
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31265 INVITE
Content-Length: 0


Received from udp:10.1.10.10:5060 at 14/11/2017 16:21:48  (400 bytes)

SIP/2.0 404 Not Found
Via: SIP/2.0/UDP 10.1.10.52:5060;rport=5060;branch=z9hG4bKd.6dsp0xvgtelm.q8y6jz0nfvf
To: <sip:612****@10.1.10.10:5060;user=phone>;tag=668aa37e
From: "Cordless"<sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31265 INVITE
User-Agent: 3CXPhoneSystem 15.5.3849.1 (3849)
Warning: 499 Royal3CX "Not found"
Content-Length: 0



Sent to udp:10.1.10.10:5060 at 14/11/2017 16:21:48  (430 bytes)

ACK sip:612****@10.1.10.10:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 10.1.10.52:5060;rport;branch=z9hG4bKd.6dsp0xvgtelm.q8y6jz0nfvf
Max-Forwards: 70
From: "Cordless" <sip:111@10.1.10.10:5060>;tag=95e.6dlmsj
To: <sip:612****@10.1.10.10:5060;user=phone>;tag=668aa37e
Call-ID: 21ta.717r1rrh56qngkqjdftrerho@10.1.10.10
CSeq: 31265 ACK
User-Agent: snomM700/03.55.0025 (MAC=000413611822; SER= 00000; HW=255)
Content-Length: 0