Session border controller

Woman taking a call using a headset.

Get ready for the analogue phone switch-off with session border controller and Microsoft Teams for Telephony services.

Do you want to make the most of Microsoft Teams and expand your infrastructure for the best possible telephony experience?

Integrating our cloud-based session border controller with the Teams for Telephony service offers an easy route towards transforming your campus’ telephony prior to the switch-off of analogue lines. This no-fuss solution doesn’t require you to purchase any hardware or separate services.

How does it work?

Session border controller allows Microsoft Teams to extend voice over internet protocol (VoIP) to break out across the public switched telephone network (PSTN), turning the app into a softphone client and replacing traditional office phones. The service also supports integration with existing private branch exchanges (PBXs).

By combining the power of the Janet Network, with our market leading operating partners Oracle and Gamma, this solution provides high call quality and high reliability for users and offers the ability to scale and flex as your organisation requires.

Together, these services unify your communications channels under one roof. Shifting to cloud telephony and a UC (unified communications) platform boosts collaboration, reduces costs and makes maintenance easier for IT teams.

Teams phone system provides features such as:

  • Make and answer calls
  • Merge calls
  • Transfer and ring back
  • Transfer calls between devices
  • Voicemail
  • Call transcribing
  • Auto attendance

Our M365 team can help you integrate your operational and teaching staff by configuring Teams to provide a unified communications ecosystem.

They will work with you to determine which Teams configuration is suitable for your needs and to raise your Microsoft Teams skills and capabilities, so that you are confident in making further configuration changes in the future.

Find out more

To find out more about our session border controller service, contact your relationship manager or email


There's no need to purchase hardware or separate services - get this cost-effective solution through your trusted partner.

  • Reduce your operational risks and costs by removing the need for on premises infrastructure
  • Organisations will be able to scale up or down call sessions to meet changes in demand
  • Current technology such as public switched telephone network is to be switched off, so get ahead of upcoming changes and move to digital services now
  • Investment in Oracle ‘carrier grade’ technology, hosted on the Janet Network, ensures optimised call traffic and call quality
  • Flexible pricing models are available to make clearing and periods of increased activity more manageable

Case study: University of Stirling

Session border controller service has allowed the University of Stirling to get a head start with futureproofing its telephony systems, as well as reducing their telephony costs and simplifying administration.

"It is a robust, one-stop solution and it is proving to be rock solid”.

Jim McKee, head of infrastructure, University of Stirling.

Read the full case study (pdf).

Case study: Transforming telephony at NCG

NCG has seven colleges across England, which had four legacy phone systems costing hundreds of thousands each year in line rental, call and maintenance charges. They were one of the first to try our session border controller service to transform their telephony.

"Staff are very positive about the change because now everyone has their own work phone number. There’s no phone-sharing so no one waits for a line. It just makes it easier for people to do their job."
Tom Earl, IT contract, budgets and procurement manager at NCG

Read the full case study (pdf).

Case study: The Bedford College Group

In 2022, The Bedford College Group opted to replace its existing phone system with a session border controller solution, aiming to improve reliability and reduce maintenance costs.

"We can integrate all our staff, wherever they are, into a single, unified communications system that’s managed for us by dedicated specialists who are freeing us up to do other things.”
Martin Johnson, digital innovation specialist at The Bedford College Group

Read the full case study (pdf).

Need help managing payments for our services?

Did you know you our customers can make pre-payments for Jisc cloud products and services ahead of the time they wish to use them, they can then ‘draw down’ against the pre-payment to be applied to Jisc invoices for completed projects involving Jisc products or services.

Service level agreement

Service description

The service provides a gateway between private networks and enabling VoIP telephony of Unified Communications solutions such as through Microsoft Teams, to break out into the PSTN. It also supports integration with some legacy PBX solutions. 

The service comprises SBC session licences, SIP trunk integration and SIP channels, and advice on its configuration for Microsoft Teams. As part of the service customers can purchase additional DDI numbers or choose to port existing numbers from their current SIP service provider. 

Service billing portal

The service billing portal is only for use by customers who buy SIP channels from Jisc and enables customers to view their calling history and monthly bills.

Fraud management and nuisance calls

Organisations must ensure they understand and adhere to the Janet security policy and the acceptable use policy.

The service has the provision to place a financial cap on any fraudulent calling activity and also has the option to bar calls outside of the call-minutes bundle; such as premium rate and international calls. Typically, this is done during service onboarding but can be activated or adjusted after service commencement via a request into the Jisc service desk.


Customers taking both SBC sessions and SIP channels will be billed monthly by email. The bill will include both fixed service charges and monthly call charges, in arrears. Bills require payment through a direct debit facility, to be setup between the customer and our operating partner Gamma Business Communications Limited. We will help you setup this direct debit mandate as part of the onboarding process. 

Customers taking SBC session licences only will be invoiced annually in advance for the service through Jisc’s own invoicing team, typically at the start of the academic year. 

Call minute bundles

Our three-year and one-year contracts, that include SIP trunks and channels, also come with a call minute bundle: 

  • Three-year contract – 5,000 geographical (GEO) minutes and 2000 mobile minutes per SIP channel, per month 
  • One-year contract – 5,000 geographical (GEO) minutes per SIP channel, per month
Calls included and excluded from the call minute bundle

The monthly geographical (GEO) minutes apply to calls to UK geographic numbers only. 

The monthly mobile minutes apply to calls to mobile numbers on the main UK mobile networks only. Mobile minutes are only offered on our three-year SIP contract. 

The monthly GEO minutes and monthly mobile minutes are structured to avoid per-minute billing and so the total number of calls per channel shall not exceed the limits for the monthly GEO minutes and monthly mobile minutes stated above, which are the fair usage limits. If the fair usage limits are exceeded in any month, the customer will be notified and given an opportunity to increase the number of channels to incorporate the additional minutes.  If this opportunity is not taken, JSL reserves the right to charge a per minute price for the additional minutes used. 

The monthly GEO minutes and monthly mobile minutes reset each calendar month so any used minutes will not roll-over to the following month. 

Calls to 01, 02 or 03 numbers are considered UK geographic numbers for the purposed of the monthly GEO minutes but calls to 03 numbers must not exceed 15% of the total number of calls made from the endpoint. Calls to any other numbers including, by way of example only, 08, 09, 118, international or premium rate numbers are not considered UK geographic numbers and calls to these numbers are therefore not included in the monthly GEO minutes. 

Calls to mobile numbers not on the main UK mobile networks and calls to international mobiles are not included in the monthly mobile minutes. 

All calls for minutes not falling with the monthly GEO minutes or monthly mobile minutes will be charged according to the rates set out in the current call charges tariff, which is available on written request from your JSL service manager by contacting them at

End user’s location recording

999 is the national emergency response service in the UK. 112 is the pan-European equivalent to 999 and can be used in the UK.  

Jisc’s SBC service supports 999/112 public emergency call services and such calls will be routed to the national emergency call handling agents. However, these services do not operate in the same way as PSTN fixed line 999/112 public emergency call services; connection to such services may not be possible in the event of a service outage caused by loss of end user connectivity to the internet for whatever reason. 

In such circumstances the end users should use their PSTN line, or mobile phone, to make the emergency call.

Furthermore, it may on occasions not be possible for emergency services personnel to identify the end user’s location and telephone number so this information should be stated promptly and clearly by the end user when making such a call. 

Support for call centres

The functionality needed to run a call centre are outside of the current service offering.

Service levels

Administration of the service

The Jisc service onboarding group administer quotes and handle provisioning, contract administration and upgrades for this service. 


Organisations wishing to use the SBC service will need a reliable internet connection. Eligibility for a Janet IP connection is detailed in the Janet Network connection policy.

Furthermore, organisations will need to accept the service configuration parameters which are shared as part of the customer requirements gathered at the start of the onboarding process. The service configuration parameters are available from your relationship manager. 


Your relationship manager can request a quote for the service. We will issue quotes within five working days of the request. Quotes are valid for 30 days.


Customers will be onboarded within 45 business days of receipt of all service onboarding forms by the service onboarding group. This includes the return of the signed service agreement and the completed direct debit mandate. If you have asked us to port your (transfer) existing numbers into the Jisc SIP service this can add an additional 14 days to the onboarding SLA. 

Upgrades of existing service will also be actioned within 45 business days. As a new service this is likely to change in the first six months following the launch of the service.

Cancellation of services require 30 days written notice and will be implemented within 20 business days of our confirming your request, unless the cancellation is prevented by reasons beyond our control. 

Target availability

The service is offered for 24 hours every day of the year. It relies on a number of components:

  1. Reliable internet connection such as the Janet Network.
  2. Our SBC platform - the platform uses a ‘carrier grade’ Oracle SBC in a high availability pair. The availability of the hardware is 99.999%.
  3. Resilient SIP trunk endpoints - our SIP trunk endpoints are configured as standard, with a resilient SBC, for automatic failover and failback.
Fault management and escalation

Service faults should be reported to the Jisc service desk by calling 0300 300 2212 or emailing

Service maintenance

Scheduled maintenance work is normally timed to take place in the period between 07:00 and 09:00 on Tuesdays. All such work is advertised via the trouble ticket system. The Jisc service desk will give prior warning to organisations directly affected by scheduled maintenance work.

Billing enquiries

Billing enquiries should be made to Typically billing errors will be corrected through an adjustment in the next monthly bill.

Price changes

We have a standardised timeline for the rollout of pricing changes on our services. To our best endeavours, we will issue price change notifications in the January and apply the price changes in August the same year. We understand that this better aligns with HE and FE budget setting cycles and gives a notification period which is more helpful to members. This will also exceed the three months’ notice stipulated in our terms. 

For calls outside of the call minutes bundle these are subject to change at 30 days notice. Typically, Jisc will reflect changes to our supplier costs which are based on the Telco wholesale line rental market.

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Jisc is a supplier on Crown Commercial Service’s G-Cloud framework. Purchasing services through the framework can offer significant savings.