Session Initiation Protocol (SIP) trunking is a service offered by a communications service provider that uses the protocol to provision voice over IP (VoIP) connectivity between an on-premises phone system, and the public switched telephone network (PSTN).

Technically, there is no set number of channels in a SIP trunk. The number of channels on your SIP trunk will expand and contract as you connect and disconnect calls. So, if you have 20 calls going at once, your SIP trunk will have 20 channels to accommodate these calls.

A Session Border Controller (SBC) is a network element deployed to protect SIP-based Voice over Internet Protocol (VoIP) networks.

SIP trunks offer greater flexibility than PRI by connecting calls over the internet using an internet connection. It handles as many concurrent calls as your PBX and bandwidth support.

A SIP trunk can have as many channels as you need. Most SIP trunk providers sell channel capacity in batches, but you could have 1 million channels in your SIP trunk if that's how many calls you potentially had to and from your business.

1. Log into your PBX system
2. Select the ‘Tata Communications Trunks' option
3. Create and add a SIP Trunk – this will connect the system externally
4. Name the Trunk
5. Set the outbound caller ID – your business phone number, or whichever number you intend to use
6. Set the maximum number of channels
7. Enter SIP peer details – this is how the systems talk to each other
8. Register the Trunk – you may need to set up to register with a VoIP provider; this may be called a ‘register string'
9. Click ‘Submit Changes
10. Click ‘Apply Config' – this is a key step, as it sets the Trunk live

Tata Communications is providing the Bundled IP converters as CPE and IPPBX features offered with Microsoft Teams and Cisco Powered applications.

We are providing the SIP trunk in more than 50+ countries, covering 89% of the world’s GDP.