What are the benefits of SIP Trunking?

SIP trunking provides a great alternative to ISDN lines and many of the advantages of SIP Trunking can also be found in Hosted Telephony, without the initial outlay required to upgrade to your existing system or purchase a new system.

Reasons for selecting SIP Trunking:

  • Affordable monthly rental costs lower than ISDN
  • Free UK Local, National and Mobile calls
  • Flexibility of call routing
  • Easier to manage Business Continuity than ISDN

Many systems are ready for SIP and can simply have the ISDN lines swapped for SIP Trunks. Where this is not possible providers can offer a SIP replacement service, delivering SIPs using your existing ISDN ports or, where it is cost effective, a telephone system can be upgraded to take SIP trunks. This will be dependent on the age of the system and the hardware/software configuration.

Our supplier Switch Medical will be able to help you identify if your telephone system is ready for SIPS.


A SIP trunk provides a direct connection to a secure network, with high definition voice quality and reliability.

To ensure quality is not comprised, your circuit should be configured with channels dedicated to delivering voice traffic.

Flexible and Easy to Manage

  • Ideal for premise moves and relocation
  • Further UK phone numbers can be added at any time
  • Channels can be added or removed as required

SIP allows for bandwidth to be increased and can ensure the demands you put on the system are met with a high performance response. Bandwidth can be increased and decreased as required.

Such scalability reduces the need to send users to call-waiting and voicemail, meaning you can provide the best service possible even when you’re relocating and there is no need to change your number when you move.

Reduce Costs

SIP Trunks can be increased and reduced, without the need for an engineer to visit site, so there is no need to invest in channels just in case you need them. Features such as queuing in the cloud ensure that you do not pay for more than you need and you always have the capacity to make outbound calls.

SIP Trunks offer access to a secure and reliable dedicated network. There may be some upfront installation costs, after which monthly rental is affordable and cheaper than traditional ISDN lines, and generally calls are free to UK Local, National and Mobile numbers and between sites


SIP Trunking or hosted telephony will future-proof your communications for three reasons:

  1. You can add and remove lines depending on usage and business growth,
  2. Updates can be make remotely
  3. ISDN lines will be switched off by BT in 2025.

Before this switch-off, it is recommended all businesses update their communications to avoid disruption.

For further information, visit the Switch Medical supplier page or complete the form on that page to request a quote/consultation.

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