SIP Trunking

SIP Trunking

Stripe 21's resilient IP network architecture is the high availability foundation on which our voice services are built. The unique and innovative design results from continuous systematic network re-engineering for fault reduction over a ten year period. As a result we were the first Internet Telephony Service Provider (ITSP) to guarantee Quality of Service end-to-end across our entire voice portfolio, with a 99.99% availability Service Level Agreement (SLA).

SIPS Trunk IP network architecture

We routinely achieve savings in excess of 40% on the overall cost of replacing digital ISDN lines with ISDN over IP or SIP, with no loss of quality, security and reliability.

Of the emerging standards for VoIP, SIP is the most commonly utilised in the global marketplace. SIP trunks can replace traditional ISDN services, but only if the underlying network is guaranteed for Quality of Service and the service is delivered with a full management package.

Internet-based SIP trunks may be sufficient for the home-office or micro-business (under 5 users) but for larger or more demanding business-class installations, guaranteed Quality of Service connectivity over a fully managed private network is required. SIP trunks which are Internet-based cannot offer this Quality of Service guarantee, as the Internet is not designed to sustain high volumes of simultaneous phone calls.

We understand the importance of maintaining the Quality of Service, Security and Reliability that business customers expect when replacing their ISDN lines. For that reason, our SIP trunk service is delivered to the customer premises (CPE) via two resilient connections. This is a guaranteed private circuit, which prevents any part of the call traversing the public Internet, resulting in a fully inclusive Service Level Agreement (SLA) engineered into our SIP trunk service.

The core network itself is deployed in a High Availability (HA) architecture across mirrored servers hosted in our London Docklands Data Centres. The system supports all of the SIP feature set including transparent number porting, Caller ID and Direct Dial Inwards (DDI), with crystal clear call quality and network resilience as standard.

  • To be in the UK in a BT broadband area
  • You do not need any existing infrastructure. We deliver everything you need as part of the overall managed service.
  • You do not need to change your existing Internet Service unless you want to.
  • Scaleable solution from 8 to 1000 telephones across one or many locations.
  • Retain existing telephone numbers from all major carriers anywhere in the UK.
  • Geographic and Non-geographic numbers supplied and ported.
  • New Direct Dial Inwards (DDI) ranges on request.
  • Service Level Agreement with minimum 99.9% per annum guaranteed availability.
  • Guaranteed Call Quality, Security and Reliability.
  • Ultra Low-cost VoIP call tariffs.
  • No setup charges for hardware and installation*.
  • Dual redundant premises connections for resilience.
  • Optional Fixed Price Calls with our prepay call bundles.

*Subject to our standard terms and conditions. Minimum 36-month contract term applies.


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