Imagine: you received SIP credentials from your provider, entered them in Bitrix24, but the status says 'Not registered'. Sound familiar? Most often, the culprit is NAT, UDP transport instead of TCP, or a closed port. Over 10 years, we have configured more than 50 SIP trunks for companies ranging from 5 to 500 employees. Our statistics: 80% of problems are solved by correctly specifying CallerID and configuring NAT. This article shares real experience and a step-by-step guide on how to set up a SIP trunk in Bitrix24 without surprises. Setting up a SIP trunk is not just filling out a form: you need to precisely specify the transport, handle NAT, and verify codec compatibility. We'll walk through each step and common pitfalls.
What is a SIP trunk and why do you need it?
A SIP trunk is a virtual channel operating via the SIP (RFC 3261) protocol. It replaces a physical telephone line. In Bitrix24, the trunk registers as a SIP client. The main reasons to use a trunk: keep your number (your number remains with the provider), save up to 60% on calls, and have full control over routing (IVR, queues, forwarding). Technically, a trunk is a set of registration parameters: SIP server address (e.g., sip.provider.ru), login, password, and CallerID.
How to configure a SIP trunk in Bitrix24?
Fill in the data under CRM → Telephony → Settings → Add number → Connect your number (SIP). Step-by-step instructions:
- Go to CRM → Telephony → Settings.
- Click 'Add number' → 'Connect your number (SIP)'.
- Fill in the fields according to the table:
| Parameter | Description |
|---|---|
| Server | SIP server address, e.g., sip.provider.ru |
| Login | SIP login of the account |
| Password | SIP password |
| Outgoing number | CallerID (the number displayed to the callee) |
| Transport | UDP (default) or TCP/TLS — check with your provider |
- Save and check the status in the 'Trunks' section — a green circle indicates successful registration.
Example: configuring a trunk for a company with 50 employees
Initial data: provider Mango Telecom, transport TLS, on-premise Bitrix24 without a public IP. We opened ports TCP 5060 and UDP 10000-20000, configured a STUN server. Registration completed in 15 minutes. After testing all 50 employees, calls are stable. Monthly savings on calls reached 40%.Why do NAT problems occur and how to solve them?
If Bitrix24 is behind NAT (router or cloud without a public IP), issues can arise: registration succeeds but calls don't go through or there is no audio. Example from practice: an on-premise Bitrix24 had no public IP — we configured a STUN server, opened ports TCP/UDP 5060 and UDP 10000–20000 on the router, after which calls stabilized.
Solutions:
- For cloud Bitrix24, there are usually no problems — their servers have public IPs.
- For on-premise version, specify the external IP in the SIP server settings or configure STUN.
- Open ports: TCP/UDP 5060 (SIP signaling), UDP 10000–20000 (RTP media).
We perform these steps as part of the setup, including routing tests.
Comparison: Bitrix24 number vs SIP trunk
| Criteria | Bitrix24 Number | SIP Trunk |
|---|---|---|
| Keep your number | No, you rent a new one | Yes, use your own |
| Call cost | According to Bitrix24 rates | According to your operator's rates (cheaper) |
| Setup | Simple, but number is not yours | Requires technical knowledge |
| Routing flexibility | Basic | Full (IVR, queues, forwarding) |
A SIP trunk is often 2-3 times cheaper for call costs with high volumes.
Outbound calls via trunk
In telephony settings, specify 'Outbound via SIP trunk [name]'. Then all calls from CRM will go through your operator, bypassing the internal balance. This is especially beneficial for international calls.
What is included in turnkey SIP trunk connection?
- Analysis of current telephony and provider.
- Obtaining credentials and their verification.
- Registration of the trunk in Bitrix24.
- Configuration of inbound call processing (queue/IVR/parallel call).
- Configuration of outbound calls via trunk.
- Testing inbound and outbound calls.
- Employee training.
- Guarantee of correct operation for 30 days after setup.
Experience and guarantees
Over more than 10 years, we have connected over 50 SIP trunks to Bitrix24 for companies from 5 to 500 employees. Our experience: we successfully solve problems with NAT, protocol incompatibility, and complex routing. Average setup time: 2–4 hours. Cost is calculated individually. Contact us for a free consultation — we will evaluate your project in 10 minutes! To order a SIP trunk setup, leave a request — we will select the optimal solution.