The 21CN infrastructure

As telecommunications evolved in the UK, BT deployed a number of disparate and unconnected networks to provide a range of services - from basic telephony to complex Internet connectivity. This approach inevitably left BT with a number of issues when looking to provide the next generation of high speed data connectivity. Its technical experts therefore proposed a radical replacement programme that takes the network to a single unified core.

Under 21CN, by 2012 BT is replacing traditional concentrators, switching equipment and DSLAMs at exchanges with MSANs (Multi-Service Access Nodes). The 5,500 MSANs terminate all phone and broadband connections and link into over 100 ‘Metro nodes’ where IP packets are routed and switched. The Metro nodes then link to 20 core nodes that are able to handle traffic in multiples of 10Gbps.