Avaya

Adding SIP Trunks to Avaya IP Office: A Step-by-Step Overview

If your Avaya IP Office still connects to the world through PRI or analog lines, you're paying legacy prices for a system that's fully capable of modern trunking. Moving to SIP is the highest-return upgrade an IP Office owner can make — here's how the project actually goes.

Step 1: Confirm what you have

A technician verifies your IP Office release, control unit, and SIP trunk licensing. Many systems already own unused SIP channel licenses; others need an inexpensive license add. Firmware may need updating — worth doing anyway.

Step 2: Size the trunks

Pull real usage: how many simultaneous outside calls does your business actually make? Most offices discover they've been paying for a 23-channel PRI while peaking at six concurrent calls. With SIP you buy exactly the paths you use, and add more in minutes when you grow.

Step 3: Ready the network

SIP rides your internet connection, so the assessment covers bandwidth (about 100 Kbps per call), router behavior (SIP ALG off, QoS on), and firewall rules. This step is where DIY conversions go wrong — and where experienced installers earn their keep.

Step 4: Configure and test in parallel

The SIP trunks are built alongside your existing lines: test numbers, inbound routing, caller ID verification, E911 registration, and failover behavior — all while your current service keeps working. Nothing cuts over until it's proven.

Step 5: Port and cut over

Your numbers port to the SIP carrier on a scheduled date. Calls start flowing over the new trunks; the old circuits run as backup briefly, then disconnect — and their line items disappear from your bill.

What changes for users: nothing

Same phones, same extensions, same buttons. The only visible difference is the invoice.

The math that drives it

PRI circuits commonly cost several hundred dollars monthly; equivalent SIP capacity is typically a fraction of that. Payback on the conversion is usually measured in a few months. Add our carrier price match, and this is the rare project that funds itself almost immediately — ask us to run your numbers.