Your configuration looks good, but we'd recommend checking the SWYX IpPbx configuration as per below: We installed SWYX v13.20.0.0 (released on 19.09.2022) on one of our demo systems and found that we needed to make settings in a few places in SWYX before we were able to do a SIP REGISTER with it. In order to successfully do a SIP REGISTER with SWYX we had to do this: 1. The user's "Name" had to match the "Internal Number" assigned to that user. 2. The user's "SIP User ID" (set on the "SIP" tab) had to match the "Internal Number" assigned to that user. 3. The SIP Authentication had to be set in two places. In the "Administration properties for the User" window on the "SIP" tab, and on the "Authentication" tab (in the "Authenticate via User Name and Password" section), and both authentications enabled. 4. The Login and Password in the "Authentication" tab's "Authenticate via User Name and Password" section has to match the "SIP User ID" and "SIP Password" used on the "SIP" tab. otherwise we would be getting "403 Forbidden" errors returned to us from SWYX IpPbx...   Here is a screenshot of SWYX IpPbx configuration that works:               See below for WireShark trace from our test that did a successful REGISTER with SWYX IpPbx.
  WireShark trace file: swyx_register.pcapng     Our Configuration in VoiceGuide's Config.xml was: <VoIP_Lines> <VoIP_Registrations> <VoIP_Registration> <Protocol>SIP</Protocol> <RegServer>10.1.40.166</RegServer> <RegClient>101@10.1.40.166</RegClient> <LocalAlias></LocalAlias> </VoIP_Registration> </VoIP_Registrations> <VoIP_Authentications> <VoIP_Authentication> <Realm></Realm> <Identity></Identity> <AuthUsername>101</AuthUsername> <AuthPassword>000000</AuthPassword> </VoIP_Authentication> </VoIP_Authentications> </VoIP_Lines> (the above is inside the Config.xml's <VoiceGuideConfig>...</VoiceGuideConfig> section)   If you still encounter problems please post the full WireShark trace capturing all the SIP packets exchanged, and the VoiceGuide ktTel trace, which will let us see what version of HMP is used and other settings used.   The Username is there in your screenshot. There is a "Username=998" entry in that screenshot, and username is also set in the "To", "From" and "Contact" headers. Not every SIP device/stack also includes username in the "uri" part of the "Authorization" field.   Also, if you run into SIP REGISTER or connectivity problems with other PBXs it's good to ask them to show what config is needed to have it working with a widely used SIP soft-phone - eg: MicroSIP ( https://www.microsip.org/ ). Once the PBX works with pretty much any of the widely used SIP soft-phones you'll most likely find that that this same configuration will work with VoiceGuide as well.