Go for automatic - physical-layer management - Technology Information

Communications News, Oct, 1999 by A. Panessidi

Latest physical-layer-management products eliminate manual intervention.

As enterprises become increasingly network-centric, merged voice and data networks are undergoing explosive growth globally. The complexity brought about by the network's evolution results in increasing difficulty facing network managers as they manage network cabling and resource sharing within the system's infrastructure. More and more network managers seek means to help them ensure the integrity and operation of the network while performing moves, adds, and changes (MACs), line provisioning services, and diagnostic testing.

One significant factor that can facilitate the network manager's task is the concept of physical-layer management. The physical layer is the first layer of the open systems interconnection model (OSI), defining the physical and electrical characteristics of the interface to the network, while providing a transparent transmission path for the information across a chosen medium. Managing the physical layer implies the ability to manage the network's cabling and connection infrastructure, as well as to track these resources in real time.

Although the concept of physical-layer management has been around for many years, network switching has traditionally been performed at Level 3 of the OSI model. Recent breakthroughs have equipped the once lowly physical-layer switch with a more versatile and powerful technology platform.

Typically, a physical-layer cross-connect switch is a relay-based product that houses an array of inputs and outputs within a matrix framework and simply redirects voice and data traffic emanating from external commands that prompt the switch to make, break, or move connections within the unit.

Paralleling network growth, physical-layer switch design has evolved to address a more sophisticated suite of market requirements and demands. While some matrix cross-connect switches are limited in both size and capabilities, only partially addressing market demands, one in particular has adopted an open architecture that allows total OSS and interface to third-party test equipment while supporting the complete life-cycle management of a network infrastructure.

This automated physical-layer cross-connect switch replaces the traditional "patch panel" and is the first to combine voice and data and to support up to 3,200 lines and utilize a robotic mechanism to perform cross-connect duties. This new cross-connect technology also includes built-in test ports for quick and easy connection of diagnostic test equipment, as well as fallback switching capability as an alternative path to avoid faulty connections. The robotic design minimizes the overall footprint (compared to relay-based technologies) of the switch, enabling it to fit into a 23-inch rackmount chassis and reduce real-estate costs for telecommunication applications where space is at a premium. The switch resides at the central office, and its protocol-transparent design allows it to support analog voice, xDSL, ISDN, Basic Rate, X.25, Frame Relay, Fractional T1, T1, and E1 lines. Versatile GUI-based connection management software provides unattended local or remote operation.

DATA NETWORKS

Available protocol-transparent cross-connect switches provide network managers, through a local or remote PC, the ability to share a network resource, such as a diagnostic analyzer, for more complete coverage throughout the entire network infrastructure. The premise is simple; the cross-connect matrix field allows the network manager to trigger and electronically log to move the analyzer anywhere within the network and monitor any given segment. All moves are connected and disconnected electronically, eliminating the time and expense associated with dispatching a technician to carry the diagnostic equipment and fiddle with cables at the patch panel or wiring closet.

TELECOMMUNICATION NETWORKS

Now this same principle is being applied as a solution to perform local and remote loop qualification and testing, service provisioning, and migration, as well as equipment failure fallback, while dramatically reducing overhead costs associated with maintaining and provisioning the telecommunication network's infrastructure.

The combined requirements of two of the largest and most fast-paced of the telecommunication markets are the PBX and the xDSL service environments, presenting a strong case for the benefits of managing a network at the physical layer.

At its simplest, the physical-layer management paradigm can be used to dramatically lower the overhead costs associated with managing and maintaining phone-line deployment within PBX environments--which encompass both private and public enterprises, convention centers, financial institutions, and other widespread campus architectures. In PBX environments, the new automated cross-connect switches address the key issue of how to handle moves, adds, and changes, as well as line identification and qualification, cost effectively. Provisioning and line qualification can be completed "on the fly" from an administrator's console within a matter of minutes, dispensing with the time and expense of dispatching and the manual intervention of a technician. Moreover, remote sites can now be serviced just as efficiently, eliminating costly "truck rolls."