VICIdial SIP trunk docs & guides.
Reference material for the people who configure and run carrier-grade voice. Start here if you are wiring a VICIdial SIP trunk for outbound calling, picking a codec, or learning the standards behind every call on the SIPNEX network.
The guides below cover three layers. Protocol references (SIP, RTP, E.164) explain what is happening on the wire. Setup guides for VICIdial, Asterisk, and FreePBX ship tested templates — including IP-based auth, where we whitelist your server's public IP address instead of a password. Glossaries and comparisons help you pick the right codec and trunk size for your workload.
Each guide is written for the person doing the work — dialer operators, call center admins, and PBX engineers. Missing something? Email contact@sipnex.ca and we will answer it or add it to the library. Need help beyond the written guides? Our engineers answer during business hours — not a tier-1 helpdesk, the person who can actually open the config.
Browse the library.
VICIdial SIP Trunk Setup
Complete walkthrough — the Admin → Carriers entry, sip.conf, extensions.conf, codec negotiation, outbound routes, attestation handoff.
SIP Trunk Configuration
Step-by-step SIP trunk configuration for Asterisk and FreePBX with tested templates and common pitfalls.
3CX SIP Trunk Setup
Custom trunk configuration on 3CX V20 — the license requirement, Admin Console steps, DID routing, and firewall rules.
Yeastar SIP Trunk Setup
P-Series trunk configuration — register vs peer trunk types, the Domain field quirk, DID routing, and NAT settings.
FusionPBX Gateway Setup
Carrier gateways on FusionPBX — register and IP auth, access controls, destinations, and FreeSWITCH NAT variables.
Avaya IP Office SIP Line
SIP Line configuration in Manager — licensing, ITSP domain vs proxy, SIP URIs, and the non-mergeable edit trap.
MicroSIP Softphone Setup
Register the Windows softphone to any SIP account — the Login field quirk, codec order, and NAT options that matter.
UniFi Talk Third-Party SIP
Running UniFi Talk on your own carrier — custom provider fields, the port 6767 recipe, and the three caveats.
E.164 Number Format
The international phone number standard — why normalization matters and how SIPNEX expects numbers on every API call.
VoIP Glossary (60 Terms)
Plain-language definitions for the VoIP and telecom acronyms you will encounter running dialers or evaluating carriers.
How VoIP Works
A five-minute technical explainer covering signaling, media, NAT traversal, and the moving pieces of a voice call.
RTP Protocol
How voice media actually travels over the internet — Real-time Transport Protocol, jitter buffers, and packet loss.
What Is SIP
The Session Initiation Protocol — what it does, where it lives in the stack, and why every modern carrier speaks it.
Codec Comparison
G.711 vs G.729 — which codec to choose, bandwidth vs quality tradeoffs, and how to configure a codec preference list.
SIP Response Codes
The operator's reference — every class from 1xx to 6xx, the codes trunks actually return, and what each one tells you.
SIP Code 603 / Network Blocked
What a 603 means since the FCC's 603+ standard took effect — reading the Reason header and the redress path.
SIP ALG Explained
Why the router feature meant to help SIP breaks it instead — symptoms, the mechanism, and the per-router disable table.
Disable SIP ALG: Netgear
The inverted checkbox under WAN Setup, firmware differences, and how to confirm the ALG is actually off.
Disable SIP ALG: UniFi
Where the SIP module hides in the UniFi Network app, the setting to clear, and verifying from the console.
Disable SIP ALG: FortiGate
session-helper vs VoIP profile — the CLI commands that actually stop FortiOS from rewriting SIP.
Disable SIP ALG: pfSense
pfSense has no classic ALG — what to configure instead: NAT mode, source-port rewriting, and siproxd pitfalls.
DTMF Tones
The tone matrix, RFC 4733 vs inband vs SIP INFO, and why IVR digits fail on compressed codecs.
Fix Packet Loss
Symptom triage for choppy audio, the diagnosis workflow, and fixes ranked by effort — QoS, bufferbloat, WiFi.
Need help configuring?
Call (833) 665-2220 during business hours. The engineer on the line has run the platform you are configuring.