What is SIP Account & Trunk

Current Portal: open Services → SIP Lines for the selected identity's SIP details. Match its authentication, signaling transport and call-audio settings on your device; old screenshots show an earlier software version. Use your own credentials and current regional server. Private values in illustrations are hidden.

Understanding SIP Lines, SIP Trunks, and SIP Users on ILLYVOIP

What is SIP and How Does It Work?

SIP (Session Initiation Protocol) is a communication protocol used to establish and manage voice and video calls over the internet. It is the technology behind VoIP (Voice over IP) services, allowing users to make calls without traditional phone lines.

How SIP Works

1. Call Initiation – When a user dials a number using a SIP softphone, IP phone, or PBX, the SIP protocol sends a request to establish the call.
2. Session Establishment – SIP finds the recipient’s address (SIP URI or phone number) and connects both parties.
3. Call Management – During the call, SIP manages features like call transfer, hold, or conference calls.
4. Call Termination – When the call ends, SIP ensures both ends disconnect properly.

Key Features of SIP

SIP supports communication over a suitable internet connection and is used by softphones, IP phones and PBXs. Actual service capabilities, device compatibility and simultaneous-call limits depend on your setup; support in the SIP protocol is not a promise that every feature is enabled on your account.

What is a SIP Account?

A SIP account is an internet-based phone system that allows you to make and receive VoIP calls using softphones, IP phones, or PBX systems. It acts as your unique ID in the VoIP network, connecting you to the telephony system.

Your account includes a main SIP identity. Before calling, complete any required verification, check the available balance and routing package, and configure the intended device.

What is a SIP Trunk?

A SIP trunk is a virtual phone line that connects your SIP account to the public telephone network (PSTN) or other VoIP providers. Unlike traditional phone lines, SIP trunks allow you to handle multiple calls at once and scale easily.

IllyVoIP provides SIP trunking services, which means you can connect your PBX system and route calls efficiently while saving costs.

Difference Between SIP Account and SIP Trunk

• A SIP Account is a single user ID that allows you to register on a softphone, IP phone, or PBX.
• A SIP Trunk is a connection that allows multiple SIP accounts or extensions to make and receive calls through a VoIP provider.

What is a SIP User?

A SIP identity identifies a line in your IllyVoIP account. With password authentication, configure its SIP username and SIP password in your device. With IP authentication, authorization uses the configured public source IP of your PBX. Use the mode shown for that line; do not assume every connection needs password registration. Your Portal login password is separate.

On IllyVoIP, every account automatically comes with a default SIP user, but you can also create multiple SIP users for different purposes, such as:

• For employees or agents (each user can have a separate SIP login).
• For different devices (using one account on multiple devices).
• For PBX integration (connecting to external VoIP systems).

How to Get a SIP Account on IllyVoIP?

1. Sign up for an account on IllyVoIP.
2. Once registered, a SIP user is automatically created for you.
3. Open SIP Lines and check the selected line’s authentication mode and Technical endpoints. Use the SIP password only for password-authenticated devices, or configure the correct public source IP for an IP-authenticated PBX.
4. Use these details to configure your Softphone, IP phone , or PBX System.

How to Use a SIP Account?

Once you have your SIP credentials, you can:

• Configure it on a softphone like Zoiper, X-Lite, or MicroSIP.
• Set it up on an IP phone for office use.
• Integrate it with a PBX system like 3CX, Asterisk, or FreePBX.
• Use it for SIP trunking and call forwarding.

Conclusion

SIP is the backbone of VoIP communication, allowing you to make calls over the internet without the need for traditional phone lines. A SIP account lets you connect to VoIP services, while SIP trunks handle multiple calls efficiently.

Use the existing main SIP identity or create another line for a separate device. Create an agent account when a teammate also needs Portal access, then choose appropriate permissions. Incoming-number routing is a separate configuration from the device connection.

For more details, check our guides on:

• How to Set Up a SIP Accounts on Softphone or PBX systems