Murton Consultancy & Design Ltd

Murton Consultancy & Design Ltd operates in the field of Metro SDH (Synchronous Digital Hierarchy) and associated Metro Ethernet.

Metro SDH refers to the well established Optical Transport technology used in voice and data transmission networks within a metropolitan or regional area. SONET is the equivalent to SDH in the USA and Canada.

SDH technology has reached its third generation with one of its key features being more efficient transport of data, which is the main focus of the company. The signal transported may be Ethernet to link Enterprise LAN locations, Fibre Channel to connect Enterprise SAN installations or ATM.

New extensions to SDH include Virtual Concatenation, Link Capacity Adjustment Scheme (LCAS) and Generic Framing Procedure (GFP). These new techniques enhance the ability of SDH to carry data.

Current WAN leased lines carried over the SDH network are mostly Nx64k or E1 (2M). The next step up in bandwidth is at E3/DS3 (34M/45M) with STM-1 (155M) beyond. These steps have a very coarse granularity, in terms of capacity and hence cost. In addition they have different physical interfaces. A much better approach is to provide an Ethernet physical interface (10M/100M or 1000M) to the leased line. Bandwidth can then be allocated to the leased line in VC-12 (2M), VC-3 (50M) or VC-4 (150M) increments.

Another aspect of third generation SDH is the move from OSI to IP protocols in the SDH Data Communications Network (DCN) as defined in ITU-T G.7712. The main purpose of this is to provide a cost reduction in the management of SDH Networks.

The migration from OSI to IP involves the application of the integrated IS-IS protocol (RFC 1195) for IP and OSI routing. This protocol is well established in the backbone of the Internet. Generic Routing Encapsulation (GRE) is the scheme used to tunnel OSI over IP (RFC 2784) and IP over OSI (RFC 3147).

Metro Ethernet is the application of Ethernet as a networking technology within a metropolitan or urban region. Metro Ethernet can be operated as a stand alone solution or in conjunction with an SDH network.

The company offers consultancy and design services in these areas. This can range from individual consultancy on a specific topic or a complete project design and implementation. The scope of the work can involve whole network issues, product architectures or detailed sub-system designs.