Yhman.net.uk
Title
YHMAN Home page
Description
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.
