T 10.10.10.118:52377 -> 10.10.20.105:5060 [AP] #1
REGISTER sip:pbx.local.voip SIP/2.0.
Via: SIP/2.0/TCP 10.10.10.118:52377;alias;branch=z9hG4bK.~qSx-dqOw;rport.
From: "Davor Jovanovic" <sip:527@pbx.local.voip>;tag=Lz0qDtRvM.
To: "Davor Jovanovic" <sip:527@pbx.local.voip>.
CSeq: 22 REGISTER.
Call-ID: Sd~zV4b6WI.
Max-Forwards: 70.
Supported: replaces, outbound, gruu.
Accept: application/sdp.
Accept: text/plain.
Accept: application/vnd.gsma.rcs-ft-http+xml.
Contact: "Davor Jovanovic" <sip:527@10.10.10.118:52377;transport=tcp>;message-expires=604800;+sip.instance="<urn:uuid:0d41d0aa-fd67-008d-8a04-2848f48f5eb8>".
Expires: 0.
User-Agent: Linphone Desktop/4.2.4 (Windows 10 Version 2004, Qt 5.14.2) LinphoneCore/4.4.9-1-g18c59c7db.
Content-Length: 0.
Authorization:  Digest realm="local.voip", nonce="59422c75", algorithm=MD5, username="527",  uri="sip:pbx.local.voip", response="023fdd9663111312fc65f0e7f1e9e9ef".
.

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T 10.10.20.105:5060 -> 10.10.10.118:52377 [AP] #3
SIP/2.0 401 Unauthorized.
Via: SIP/2.0/TCP 10.10.10.118:52377;alias;branch=z9hG4bK.~qSx-dqOw;received=10.10.10.118;rport=52377.
From: "Davor Jovanovic" <sip:527@pbx.local.voip>;tag=Lz0qDtRvM.
To: "Davor Jovanovic" <sip:527@pbx.local.voip>;tag=as6b3ad762.
Call-ID: Sd~zV4b6WI.
CSeq: 22 REGISTER.
Server: SRCE PBX.
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE.
Supported: replaces, timer.
WWW-Authenticate: Digest algorithm=MD5, realm="local.voip", nonce="7198d479".
Content-Length: 0.