SONET will play a major role in improving how business customers are connected to public network services. SONET - the Synchronous Optical Network - describes a set of specifications for high-speed, digital, fiber-optic communications equipment.
Unlike frame relay, Switched Multimegabit Data Service (SMDS) and Asynchronous Transfer Mode (ATM), which are still jockeying for position, SONET's role is well defined and its functionality cuts across all communication requirements. The SONET standards cover three primary areas:
1. A multiplexing format for combining lowerspeed digital channels into high-speed transmission aggregates.
2. Optical interfaces for connecting fiber terminals from different vendors.
3. A set of network management protocols.
Layer 1 Doesn't Mean the Bottom
SONET's functions address the physical layer interface, but us "bit jockeys" consider Layer 1 to mean first in importance. Performance at Layer 1 affects the cost and availability of services like ATM or TCP/IP that run over it.
Until now, most of SONET's focus has been on the interoffice network - the connections between central offices in a carrier's network - but it will also make a major contribution to network access. SONET incorporates key functions required to physically connect virtually any service - switched voice, dial-up digital services or private-line digital services for LAN interconnection, terminal-to-host or the full range of other nonvoice requirements - to the network. * Cost: While direct T1 private line access to IXCs has become …
Комментариев нет:
Отправить комментарий