Peering Information

BT's extensive peering arrangements are a critical component to providing outstanding connectivity and performance for our customers as well as increased service resilience through diversified routing. Peering is the bedrock of our network and we actively expand our peering capacity in line with traffic growth to maintain world class performance.

BT's Internet network capability consists of BT's European Backbone (AS5400), the UK (AS2856), plus in-country Internet networks in Ireland, Italy and Spain. BT also has Internet networks in Latin America and the Global Infonet Internet Backbone (AS3300).

Peering Policy Principles

BT has a selective peering policy - we select our peers on the basis of their performance, capability and where our traffic needs to go. Our choice of peering partner can have a direct affect on our customers and we understand that this demands very high performance from our peering partners as well as from ourselves to deliver a mutually beneficial outcome for BT and our peering partners in terms of best price/performance for our customers.

Customers demand that the internet content and services they enjoy should be available all of the time. To achieve this goal, peering should not be dependent on the infrastructure of a single site. BT.s objective is to connect all peers via at least 2 sites with geographic separacy. If this is not immediately available, BT will wish to discuss with you a roadmap and timeline to provide separacy, to provide the best experience for your and our customers.

The backbone cost burden associated with settlement-free peering traffic exchange should be equitably shared. Regardless of the direction or type of traffic exchanged between the networks, the routing practices and location or interconnection points should be such that each party bears a reasonably equal share of backbone costs.

Should the nature of the initial interconnection change and result in an imbalance in the incurred network backbone costs between the two Parties, BT will seek to renegotiate on the interconnect placement, or on other means through which a balance between the Parties commercial interests can be struck.

Our preference is to peer AS5400 with a network having a consistent AS and consistent announcements, interconnecting in multiple geographically distributed locations defined on a per-peer basis, with a symmetrical flow of traffic either via IXPs or via private interconnects generally at 1GbE minimum. We would strongly prefer that an interconnecting network should have a single AS.

In the case that the peering party has significant excess inbound traffic volume to deliver to BT (significantly in excess of that being sent outbound by BT to that party) then the parties should agree the routing behaviour expected of one another within reasonable technical, and operationally-feasible bounds.

When the peering partner has network presence in multiple countries or continents where BT also has Points Of Presence, it will be desirable to open peering legs in at least two locations, and maybe more, subject to the cost/benefits of PoP build-out. This is to ensure that the traffic is exchanged optimally in the respective countries/continents and peering interconnections benefit both partners equally.

We select our peers carefully to achieve these goals and expand our capacity to them in line with traffic growth into public exchange points (where we peer both over the public infrastructure and privately) and via private peering links into our main PoP sites.

Through this policy we have established extensive, geographically diverse, peering interconnections designed to ensure minimal off-net latency to and from our customer's traffic destination. Much of our customer's traffic is domestic. We minimise latency using Nearest Exit routing to achieve more than 95% of this domestic customer traffic shipped off-net within the country it originated.

Our international traffic also benefits from our depth of reach throughout Europe at all the major European IXPs and from our connectivity to US networks via IXPs in the USA.

Where do we private peer?

BT UK Networks, AS2856 is located at the following sites:
UK Site: ASN
London Docklands - Telehouse 2856
London Docklands - Redbus/Sov Hse 2856
London - Interxion 2856
Slough - Equinix LD5 2856

Where do we do public peer?

If you want to peer with us.

If you are interested in peering with BT on AS2856, AS3300 and/or AS5400, please visit our Peering Request page.

Any Operational problems with AS2856 peerings can be reported to the BT IPP NOC via with a follow-up call on 0800 811 343 options 2, 3, 1.

Any Operational problems with AS3300 or AS5400 peerings can be reported to the BT NOC with a follow-up call on +44 203 7882214 option 1.