Updated 2026-05-31

Support / Voice / SIP Trunking

SIP trunk configuration and troubleshooting.

Guides for the trunk-level settings that govern how a PBX, SBC, or application connects to VoiceTel — authentication mode, DID routing behavior, registration domains, and common failure modes.

Free trial SIP trunking overview

Articles

• Authentication types and DID routing

  The four supported authentication types (Digest, Lax, IP, Strict) and how they interact with DID routing — Digest routes versus Route Destinations, IP address lists, geographic routing, and the outbound SIP requirements that apply when IP authentication is in use.

• Inconsistent PBX registration

  Checklist for intermittent registration failures: credentials, ACL placement on Switchvox-class systems, profile-restart verification, in-memory ban clearing, and registration-target rotation.

Related

• Open-source PBX platforms — FreePBX, FusionPBX, 3CX, raw Asterisk.
• Session Border Controllers — AudioCodes, Cisco CUBE, FreeSWITCH, Asterisk.
• Firewalls — SIP-aware NAT, ALG behavior, port allowances.
• IP phones — provisioning and registration for desk phones.