Global SIP

Global Session Initiation Protocol (SIP) unites your infrastructure and uses data networks for voice calls. Speeding up your transformation to digital voice and collaboration solutions.

Lay the foundations for cloud transformation

Embrace a digital alternative to traditional voice services, as you meet growing business demands.It’s resilient, scalable, sustainable design paves the way for unmatched efficiency and performance.

  • Reduced costs

    Reduce costs by combining voice and data networks and removing legacy interfaces. Calls between your sites, even in different countries, are free.

  • Easy integration

    Easily integrate voice calling with your existing collaboration platforms such as Microsoft Teams, Zoom or Cisco Webex.

  • A more sustainable design

    With higher levels of energy efficiency and a leaner architecture, our Global Voice network has a lower carbon footprint than our legacy network, helping customers reduce their Scope 3 emissions impact.

Why choose BT for voice networks

Truly global

We provide services to customers in more than 27 countries around the world, hosting over five million users and carrying ten billion minutes annually.

Secure and compliant

We build end-to-end security into all our solutions. Our 3,000 security experts protect governments, critical national infrastructure and global corporations from more than 6,500 daily cyber attacks.

Outstanding network quality

We are constantly monitoring voice quality and proactively resolving faults, giving your people a brilliant calling experience.

Helping Kingston’s drive for students

Kingston University’s outdated technology couldn’t cope with incoming calls during busy recruitment drives – making them lose potential students. See how our IP solution transformed how people work at the university.

Read the case study

The future is in the cloud

Find out how Global SIP can get you closer to the cloud-based future of communications.

FAQs

Session Initiation Protocol (SIP) is used to provide voice over IP (VoIP) connectivity between a Private Branch eXchange (PBX) and the Public Switched Telephone Network (PSTN). Global SIP is an alternative to Integrated Services Digital Network (ISDN30) that uses your data network to route your PSTN traffic. It can help improve organisational flexibility, offer additional resilience and operational efficiency whilst helping to reduce costs.

A SIP channel is the capacity needed to carry a single telephone call and is an attribute of both a trunk and a trunk group. The number of channels determines how big a trunk or trunk group is.

A SIP trunk is the connection to a PBX with a designated number of channels. This channel capacity is also called the trunk’s Call Admission Control (CAC).

A SIP trunk group in turn also has a designated number of channels and is a container for trunks. So trunks sit in trunk groups and multiple trunks can sit in the same trunk group. This capability is useful if you want to separate a set number of channels for your business or your contact centre.

Global SIP offers in-built resilience at no extra cost, routing calls to an alternative (stand-by) site if your primary site becomes unavailable. Some providers will charge for stand-by channels, but BT only charges for channels in use at any time.

BT estimates that when fully rolled out, the new Global Voice network will have an 81% lower carbon footprint compared to BT's current voice network. This means customers on the new network will be able to reduce their Scope 3 carbon emissions. Using the Greenhouse Gas Protocol ICT Sector Guidance by GeSI, BT has generated the following:

  • In use, next-gen Global Voice will consume 152 MWh/year versus its existing network at 1,962 MWh/year—a 92 percent reduction.
  • BT's next-gen Global Voice's total carbon footprint, based on embodied emissions plus in-use emissions, will be an estimated 279 tonCO2/year after completion of the network transformation, versus 1,458 tonCO2 for its existing network—an 81 percent reduction in total carbon.
  • Moreover, the new Global Voice will be built using 120 devices versus 538 devices—a 78 percent reduction versus its existing network.

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