SIP Trunks

Business SIP Trunks offer far more than a traditional ISDN business telephone line service. Take full advantage of the latest communications technology such as Skype for Business combined with intelligent call routing and diverts, flexible telephone numbering, inclusive calls and comprehensive Disaster Recovery options.

SIP trunks allow you to can keep your existing numbers to maintain business continuity or get new numbers. You can also use any local area numbers no matter where you are located. One of the greatest advantages is that you won’t have to give up your telephone numbers if you move out of the area.

Compared to BT ISDN30, using Business SIP Trunks could produce significant savings across many areas – installation costs up to 90% cheaper, up to 50% on line rental and as much as 25% on call charges.  In addition, customers with multiple sites could get the benefit of free calls between those sites.

Unlike traditional ISDN lines, if you only want a certain amount of line, you can have exactly that.

Unexpected events such as snow, floods and power failures won’t disrupt your business. Because our SIP Trunk service sits in the “cloud”, unexpected events such as extreme weather will not impact on the smooth running of your business. Disaster Recovery features are provided as part of the service so you can continue to receive calls regardless.

Service Summary

  • Next generation business line service
  • Better value than traditional lines such as ISDN
  • Cheaper line rental and call costs
  • Low installation costs and faster lead times
  • Faster installation lead times
  • Inclusive call bundles.
  • Compatible with most IP-based phone systems
  • Skype for Business compatible
  • Flexible contract terms
  • Flexible telephone numbering
  • Comprehensive Disaster Recovery options
  • Outstanding and experienced UK-based support

Compared to BT ISDN30, using our Business SIP Trunks will save you a very significant sum on installation costs. This could be a saving of 90% or more based on the installation of a BT ISDN30 bearer with 30 channels on a 12 month contract term (BT pricing checked 03/12/15). One of the other major benefits for UK SME customers is the immediate and significant reduction in operating costs. By utilising Business SIP Trunks you could save up to 50% on line rental compared to BT ISDN and up to 25% on call charges. Customers with multiple sites also benefit from free calls between sites.


If you want exactly 3 lines, you can have just that. You only pay for what you need on a simple channel rental basis and the minimum number of channels you can order is just 2 compared to 8 on ISDN30. This is great for businesses that would otherwise pay for traditional line services they do not use or require but are forced to, due to the minimum channel commitment on traditional ISDN30 services. For larger businesses that need to scale the number of channels required up or down and do so quickly during peaks and troughs in business, SIP Trunks are perfect for this scenario. You can have as many SIP Trunks as you require without any additional charges to increase or decrease the number of channels required.

Single Supplier

Compared to traditional line services, the benefits of SIP Trunks are many and varied which includes reduced set up costs, faster service delivery, better value line rental and call charges, greater service and telephone numbering flexibility, vastly superior Disaster Recovery capabilities and much more besides. We provide end-to-end support for our SIP Trunk and access solutions meaning one supplier for PSTN lines, broadband, router, SIP trunks, telephone numbering, diverts and Disaster Recovery plans saving you hassle, time and money.


Oxtelecom provides total flexibility when it comes to the numbers you want to use for your SIP Trunk service. You can keep your existing numbers or get new numbers. You can also extend your business reach and use any local area numbers no matter where you are located. With our CLI Flexibility service you can also use any telephone number to display to called parties. One of the biggest benefits is that unlike traditional business telephone lines, you won’t lose your telephone numbers if you move out of your local exchange area.

Disaster Recovery

Unexpected events such as snow, floods and power failures won’t disrupt your business. Because our SIP Trunk service sits in the “cloud”, the service provides Disaster Recovery features that allow your organisation to carry on receiving calls whatever the occurrence and nature of the unexpected event. Traditional business lines just cannot provide the same level of service or functionality without going to great expense.