SIPcity supports two methods for connecting your 3CX Phone System to our SIP Trunking platform: SIP Registration (via username/password) and Static IP SIP Peering (no registration required). This guide covers both options, with a focus on Static IP SIP Peering for business-grade setups.
Prerequisites
-
3CX v18 or later
-
A valid SIPcity trunk with either username/password credentials or a whitelisted IP for SIP Peering
-
Your outbound public IP must be known and stable (for IP-based peering)
Option 1: SIP Registration (Username and Password)
Use this method if SIPcity has issued credentials.
Trunk Setup
-
Go to SIP Trunks > Add SIP Trunk
-
Choose Generic SIP Trunk
-
Set the following:
- Registrar: sip.sipcity.com.au (or as provided)
- Port: 5060 (UDP) or 5061 (TLS)
- Authentication ID/Username: Your provided SIP user ID
- Password: Your provided password
-
Leave IP-based Authentication disabled
-
Configure DID routing and codecs as needed
Option 2: Static IP SIP Peering (No Registration)
Recommended for customers with static IPs.
Enable Peering in SIPcity
-
Log in to your SIPcity account
-
Navigate to Switchboard
-
Select your main peering phone number
-
Go to Preferences
-
Locate SIP Peering and enable it
-
Enter your primary IP address (optionally add a failover IP address)
-
Click Save
Create the SIP Trunk in 3CX
-
Log in to the 3CX Management Console
-
Go to SIP Trunks
-
Select Add SIP Trunk
-
Choose Generic SIP Trunk
General Tab
|
Setting |
Value |
|---|---|
|
Registrar/Server |
103.55.116.65 |
|
Port |
5060 |
|
Authentication |
Leave blank |
|
Username |
Leave blank |
|
Password |
Leave blank |
Options Tab
|
Setting |
Value |
|---|---|
|
Transport Protocol |
UDP |
|
SRTP |
Disabled |
|
Re-register Timeout |
0 |
|
Public IP in SIP header |
Leave blank |
DID Numbers Tab
Add your SIPcity numbers exactly as issued. Example format: 6125638544
Route each DID to the appropriate extension, ring group, or IVR within 3CX.
Network Requirements
|
Setting |
Value |
|---|---|
|
SIP |
UDP port 5060 to 103.55.116.65 |
|
RTP |
UDP ports 9000–20,000 |
Outbound Rule Setup
Configure outbound rules to match numbers dialled by your users:
|
Setting |
Value |
|---|---|
|
Prefix |
0, 00, 13, + |
|
Strip Digits |
No strip |
|
Prepend |
Leave blank |
|
Outbound Caller ID |
61756385444 |
|
Trunk |
SIPcity (IP) |
This rule allows local, mobile, international, and E.164 (+61) formatted numbers to route via SIPcity. Add a second rule for specific patterns (e.g. international 00 calls) if needed.
Troubleshooting
|
Symptom |
Likely Cause |
Fix |
|---|---|---|
|
No outbound call |
Number does not match an outbound rule |
Add or correct dial prefixes |
|
No SIP INVITE seen on SIPcity |
3CX not matching a route |
Create a fallback rule with X. prefix |
|
“No user or outbound rule found” error |
Dialled number doesn’t match rule |
Review and test dial pattern |
|
Outbound call fails with 403/404 |
Caller ID not valid |
Set 61756385444 as outbound caller ID |
|
Inbound calls working, outbound not |
SIP trunk is inbound-only |
Enable “Allow outbound calls” in trunk settings |
Firewall and NAT
Ensure your outbound firewall rules allow:
- UDP port 5060 from your PBX to 103.55.116.65
- RTP media range: UDP ports 9000–10,999 (as per your 3CX RTP settings)
- SIPcity must see your real public IP, not a translated one
Final Checklist
|
SIPcity has whitelisted your public IP |
✓ |
|
3CX trunk set to “Do not require – IP based” |
✓ |
|
Re-register timeout set to 0 |
✓ |
|
DID added in 3CX exactly as received |
✓ |
|
Outbound rule matches all formats used by staff |
✓ |
Summary
Although SIPcity is not a certified 3CX SIP trunking provider, many 3CX customers connect successfully via both registration and peering. We provide detailed connection guides, support for both methods, and have proven success with many 3CX customers across Australia and the US.