Country Guides ·
SIP Trunk USA: Routes, CLI and Compliance Guide
STIR/SHAKEN attestation, 10DLC-era caller ID expectations, TCPA limits and how US routes are tiered.
Blog
Notes from the network team
How routes are judged, why calls fail, what regulators require and how to wire a trunk into your PBX. Written by the people who answer the NOC tickets.
Setup & Troubleshooting ·
SIP Error Codes 401, 403, 404, 408, 480, 486, 503: Causes and Fixes
What each response really means on a trunk, where to look in the trace, and the fix that usually works.
Wholesale VoIP ·
ASR and ACD Explained: How to Judge a VoIP Route
The formulas, healthy ranges by traffic type, and the patterns that signal a route is being gamed.
Wholesale VoIP ·
CLI vs Non-CLI Routes: What Actually Changes for Your Calls
Answer rates, callee trust, compliance exposure and which traffic belongs on which tier.
SIP Trunking ·
What Is a SIP Trunk? A Plain-English Guide for 2026
Channels, call flow, how it compares to PRI, and what you actually pay for.
SIP Trunking ·
SIP Trunk vs PRI: Cost, Quality and Migration
A cost comparison and a migration checklist for teams still running E1/T1 circuits.
Wholesale VoIP ·
How to Choose a Wholesale VoIP Provider (12-Point Checklist)
Twelve checks to run before you send a single minute to a new carrier.
Compliance ·
STIR/SHAKEN Explained for Call Centres
Attestation levels A, B and C, and what each one does to your answer rates.
Compliance ·
UK Caller ID Rules: What Ofcom Requires
Valid, dialable CLI, number ranges you can present and what gets blocked.