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YHMAN II


Topology
 

PoP Schematic
 

PoP Implementation
 

Overview Schematic
 

 The YHMAN II core is based on leased fibre-optic cables which are supplied and maintained by Kingston Communications Ltd on a 10 (+2) year contract worth £4.5M. Links into Hull are leased ethernet circuits for commercial reasons. Direct access to fibre-optic cables enables the scaling of bandwidth at low cost as demand increases and provides a flexible transmission platform over which a range of services can be offered. Every University in the region is served by the core network, while access circuits for customers such as Further Education Colleges are based on leased ethernet services to the most convenient core point of presence. 

The initial IP service on the core network is a true "Metrolan" with ethernet and layer 2 switching throughout. Routing to and from the national JANET network is at Leeds, again using fibre-optic cables. The network is configured in multiple rings for resilience with "spanning tree" being used for continuity of service in the event of the failure of a single link. For privacy and robustness, the traffic for  each site (or site cluster) is carried on separate VLAN. 

The fibre-optic cable network is implemented as point to point circuits. Adva FSP 2000 DWDM (Dense Wave Division Multiplexing) devices drive the links. These are capable of transmitting multiple laser light signals through 80km or more of fibre-optic cable. Each signal is of a different colour (wavelength or lambda). Each lambda runs at 2.5Gb/s and can carry two 1Gb/s ethernet links. The initial implementation is with a single lambda, but link speed can be scaled to 16Gb/s simply by adding cards to the Adva FSP 2000. It is expected that link speed can be scaled to at least 64Gb/s in the future. 

The core ethernet switches are Cisco Catalyst 4507R chassis based gigabit switches with up to 64Gbps and up to 48Mpps throughput and a high degree of resilience. Only layer 2 switching is implemented though these devices are capable of layer 3 routing. 

Routing is required to JANET and this is done by a resilient pair of Cisco Catalyst 6509 IPv6 capable routers with 720Gbps switch fabric and up to 400Mpps throughput. For Grid services support, multicast has been implemented.