Bolstering Ethernet, storage services

Getting the most out of Ethernet and storage-area network services is the topic of our Technology Update this week.

Specifically our author (jackhunt@nortelnetworks.com) looks at what’s known as the Generic Framing Procedure (GFP) technology to handle these tasks.

In a nutshell GFP was devised as a way to offer more bandwidth-efficient ways of packing Ethernet or storage traffic into a SONET network.

According to our author, GFP can be deployed as an interface on an optical switch and lets customers more efficiently utilize their SONET circuits. For example, customers could use GFP at the edge of leased SONET circuits (such as OC-3, OC-12, OC-48) and can then allocate portions of that circuit using virtual concatenation, or VCAT, for storage, voice, data, video, etc. VCAT is a transport technology defined by the ITU-T (G.707/G.783) to extend the utility of the SONET transport layer by allowing bandwidth to be allocated in multiples of 50M bit/sec Synchronous Transport Signal increments using up only the bandwidth required by an application.

In combinations with other advanced SONET technologies such as link capacity adjustment scheme (LCAS), which allows for dynamic resizing of those pipes, large corporations or carriers could build pipe sizes arbitrarily to accommodate different traffic types.