SIP Trunking

A Smarter Alternative to ISDN

What Is a SIP Trunk?

Think of a SIP trunk as a virtual version of ISDN.

It connects your phone system to the outside world—just like ISDN—but it’s:

Delivered over the internet
Cheaper
More scalable
Future-proof

With the UK’s ISDN network shutting down in 2027, SIP trunking is the logical step for businesses that want to keep their on-premises systems without moving fully to cloud VoIP.

Is SIP Trunking Right for You?

Yes—if your business has:

A traditional or modern on-premises PBX
Numbers you want to retain
No immediate plan to move to hosted VoIP
Concerns about cost or downtime during migration

Even older phone systems can work with SIP using a gateway that translates SIP to ISDN.

We Handle Everything for You

You don’t need to lift a finger.

Litenet manages the entire migration process:

Number porting
SIP trunk configuration
Compatibility checks with your current PBX
Comms room space planning

We’ll coordinate with your existing system maintainer to ensure seamless integration.

No surprises. No downtime. Just modern telecoms, simplified.

Key Benefits of SIP Trunking

Significantly Lower Costs

SIP is far cheaper per channel than ISDN
No expensive circuits or fixed 30-channel limits
Pay only for the capacity you need—and scale easily

Built-In Flexibility

Add or remove call capacity as needed
Divert individual numbers or entire ranges instantly
Route calls to mobiles, backup offices or answering services in seconds

Disaster Recovery Ready

Loss of internet or power? SIP trunks let you redirect traffic with one click
Keep your business reachable—even during outages

Avoid the ISDN Shutdown Rush

With the 2027 deadline fast approaching, many businesses will scramble to migrate.

Switching now means:

Lower risk
Easier scheduling
Better planning

Still running ISDN lines?

Let Litenet help you migrate to SIP trunking—quickly, smoothly, and cost-effectively.

Call: 01908 794 794 Email: info@litenetuk.com

Or reach out via our Contact Page below.