What is SIP trunking?

What SIP trunking is

A SIP trunk is a virtual phone line that carries voice calls between your business phone system and the public telephone network over an internet connection. It replaces the physical lines a company once rented from a telephone operator.

SIP (Session Initiation Protocol) is the standard that sets up, manages and ends those calls. Your phone system, usually an IP PBX, a cloud PBX or a contact-centre platform, connects to the provider's network, and the provider sends and receives calls on your behalf.

How a call travels

1. Someone dials your business number. The provider receives the call from the telephone network.
2. The provider sends the call to your phone system over the SIP trunk.
3. Your system rings the right extension, queue or IVR menu.
4. For an outbound call, the same path runs in reverse: your system sends the call to the provider, who delivers it to the destination network.

Why businesses switch

• Fewer physical lines. Capacity is a number of simultaneous calls on the trunk, not a bundle of lines you have to install.
• One connection for many sites. Offices and remote teams can share the same trunk and numbers.
• Easier changes. Adding capacity or numbers is a change on the account, not a site visit.
• Control over routing. Calls can be sent to different teams, offices or fallback destinations.

What to check before choosing a provider

• Who owns the connections. A licensed operator with direct interconnects is not reselling someone else's capacity. Ruach is a licensed Nigerian operator with direct operator connections.
• Channels and capacity. How many simultaneous calls you need, and how easily it can grow.
• Call routing and failover. What happens if one route fails.
• Numbers. Whether the provider can supply DID numbers and toll-free or vanity numbers for your inbound calls.
• Reporting. Call records and analytics so you can see call quality and volumes.
• Connection and security. How your system authenticates to the trunk, and whether the provider supports your equipment.

SIP trunking with Ruach

Ruach provides carrier-grade SIP connectivity for PBX systems, contact centres, enterprise telephony, remote teams and unified communications platforms. See the SIP trunking page and the wider Voice product. If you terminate or originate traffic as a carrier, see Wholesale Voice and SMS.

To discuss capacity and numbers for your setup, contact us.

Frequently asked questions

Do I need a new phone system to use SIP trunking?

Not necessarily. Many IP PBX and cloud PBX systems support SIP trunks. Older analogue systems may need an adapter or a replacement; ask your provider.

Can I keep my existing phone numbers?

It depends on the numbers and the operators involved. Contact us with the numbers you want to use and we will confirm what is possible.

How many channels do I need?

A channel carries one call at a time. Base the number on how many calls you expect at your busiest hour, plus some room to grow.

Is SIP trunking the same as VoIP?

SIP trunking is one way of delivering VoIP. VoIP is the general idea of voice over the internet; a SIP trunk is the connection between your phone system and the telephone network.