Creating a SIP Register Trunk on Yeastar P-Series Cloud Edition
Rather not do this yourself?
X2Comms Managed Edition customers don't need this guide — we handle all configuration and system changes as part of the service. Not yet with X2Comms? We deploy and fully configure Yeastar systems from day one. Call 03301025678 to find out more.
Introduction
A SIP trunk connects your PBX to a VoIP carrier, enabling inbound and outbound calls to real phone numbers. The most common type is a Register Trunk, where the PBX registers to the carrier's SIP server. Your reseller can supply SIP trunks alongside your Cloud Edition service.
What you need from your VoIP carrier
- SIP server hostname or IP (e.g.
sip.carrier.co.uk) - SIP port (usually
5060) - Username and password
- Your inbound phone number(s) / DDI(s)
Menu path
Extension and Trunk > Trunk, click Add.
Step-by-Step Guide
Step 1 — Basic section
| Field | What to enter |
|---|---|
| Name | Descriptive name, e.g. Main SIP Trunk |
| Trunk Status | Enabled |
| Select ITSP Template | Choose your carrier from the list, or select General if not listed |
Step 2 — Detailed configuration
Change Trunk Type to Register Trunk, then fill in:
| Field | What to enter |
|---|---|
| Transport | UDP (most carriers) |
| Hostname/IP | Your carrier's SIP server (e.g. sip.carrier.co.uk) |
| Port | 5060 (default) |
| Domain | Usually the same as Hostname/IP |
| Username | Your SIP account username |
| Password | Your SIP account password |
| Authentication Name | Usually the same as Username |
Step 3 — Advanced SIP settings (important for caller ID)
In the Advanced tab, set these three fields to Default to ensure correct caller ID presentation and smooth compatibility with UK carriers:
| Setting | Value |
|---|---|
| Remote-Party-ID | Default |
| P-Asserted-Identity | Default |
| P-Preferred-Identity | Default |
Setting these incorrectly can cause caller ID to display wrong on outbound calls or cause rejection by the carrier.
Step 4 — DIDs/DDIs tab
Add your inbound phone number(s):
1. Click the DIDs tab.
2. Click Add.
3. Enter your DDI number (e.g. 01234567890).
4. Add additional DDIs if you have multiple numbers.
5. Click OK.
Step 5 — Save and verify
Click Save and Apply.
Go back to Extension and Trunk > Trunk. Within 30–60 seconds the trunk status should show Registered (green).
Checking your channel capacity
The number of concurrent calls your trunk supports is set by your carrier. Contact your reseller if you need to check or increase your channel allocation.
Troubleshooting
| Problem | Likely cause and fix |
|---|---|
| Trunk not registering | Check username, password, and hostname — copy-paste from carrier documentation |
| One-way audio | Go to trunk Codec tab, ensure G.711 a-law (alaw) is listed first |
| Wrong caller ID displayed | Check Remote-Party-ID, P-Asserted-Identity, P-Preferred-Identity are set to Default |
| Calls failing with "403 Forbidden" | Check Authentication Name matches exactly what the carrier expects |
Summary
The SIP trunk is registered and ready. Remember to set Remote-Party-ID, P-Asserted-Identity, and P-Preferred-Identity to Default in the Advanced tab for correct caller ID behaviour.
X2Comms
There's a better way than doing it yourself
New to X2Comms?
We supply and fully deploy Yeastar P-Series systems — configured to your exact requirements from day one. No guides needed.
Already a customer?
Ask about Managed Edition — X2Comms handles all system changes and configuration for you, included in the service.