Breaking New Ground in ATM Network Management
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- More Information on Cisco ATMSolutions
SAN JOSE, Calif. -- February 20, 1996 -- Cisco Systems, Inc. is collaboratingwith the leading developers of remote monitoring (RMON) and analysis toolsolutions to advance the management of Asynchronous Transfer Mode (ATM)networks. Cisco -- along with AXON Networks, Inc., Frontier SoftwareDevelopment, Net2Net Corporation, Network General Corporation, NETSYSTechnologies, Inc. and RADCOM Equipment Inc. -- have developed a draftspecification for ATM remote monitoring that the group plans to submit tothe Internet Engineering Task Force (IETF) in March.
The draft specification defines how RMON agent software -- embedded on ATMswitches and distributed across ATM networks -- can gather informationneeded for effective network traffic analysis and troubleshooting. ATM RMONtechnology will help network managers save time and money in monitoring ATMtraffic on their networks and will help them greatly increase networkavailability for users.
"ATM networks, because of their connection-oriented nature, demand moresophisticated management systems than those that were built to manageshared-media LANs," said Keith McCloghrie, technical leader in theWorkgroup Business Unit at Cisco Systems and co-author of the ATM RMONdraft specification. "This specification aims to provide a standardframework for network managers to determine how their ATM bandwidth isbeing used and by which users."
The draft ATM RMON specification builds on the original RMON standardpublished by the IETF in late 1991, which defines monitoring anddiagnostics for network traffic at the media access control (MAC) -- or datalink -- layer and on the emerging RMON2 standard, which defines how tomonitor network and application-layer traffic.
"RMON has been a key tool for network managers to proactively monitor anddiagnose traffic on distributed, LAN-based networks," said Andy Bierman,chairman of the IETF's RMON2 working group and co-author of the draftspecification. "This specification will help standardize and deliver thesame RMON benefits for emerging ATM networks."
Network managers originally deployed RMON agents on network segments andthrough devices such as shared-media hubs, where monitoring was relativelyeasy because all traffic was visible on any port. As companies replacetheir hubs with LAN switches interconnected by ATM backbones, however,monitoring aggregate traffic patterns is more difficult because individualconversations are not always visible on the port where the probe isattached.
Monitoring ATM networks is challenging because of the extremely high speedsat which ATM devices can transport data (up to 622 Mbps and higher) andbecause those devices are moving data spread over multiple 48-byte cellpayloads instead of single, varying-length frames.
Vendors in the AMON (ATM monitoring) Consortium took a first step inaddressing ATM monitoring when they proposed a circuit-steeringspecification to the ATM Forum last year. This proposal defines how an ATMswitch should copy or "steer" traffic from individual virtual connectionsto another location, where an external analyzer or probe can be used fordata analysis. While the AMON Consortium's circuit-steering proposalhighlights how ATM traffic can be directed to an analyzer or probe, otherstandards are needed to define what data those devices should be collectingand how they should correlate or present that data to a network managementsystem.
The ATM RMON specification defines an initial management information base(MIB), using standard RMON MIB mechanisms, for data gathering and analysisat the ATM cell level. This MIB, in combination with RMON and RMON2 MIBsfor the monitoring of frames, will enable the development of new classes ofapplications for remote, non-disruptive monitoring of all aspects of ATMnetwork operation. The specification also identifies the different methodsthat can be used to collect that information, including the use of circuitsteering as proposed by the AMON Consortium to direct selected ATM virtualconnections to remote or embedded analyzers and probes.
"I believe the ATM RMON specification will improve ATM manageability," saidJohn McConnell, president of McConnell Consulting, Inc., of Boulder, Colo."This specification paves the way for the industry to develop embedded RMONprobes for ATM switches and integrate ATM with shared and switched LANmonitoring. This makes ATM even more suitable for mainstream productionnetworks."
In developing the ATM RMON specification, Cisco worked with AXON Networks,Inc., Frontier Software Development, Net2Net Corporation, Network GeneralCorporation, NETSYS Technologies, Inc. and RADCOM Equipment Inc. toidentify and address key ATM network management requirements.
For example, the ATM RMON draft specification defines how to "size up" ATMtraffic use. This includes basic cell statistics per port, per virtualconnection, per host and per conversation pair. Such information can helpthe administrator better determine if or where potential bottlenecks mayexist or find "top talkers." Because information storage is finite and thesheer speed of ATM can be a challenge to capture at full rate, thespecification also discusses data reduction or "sampling" methods thatallow the capture of frames rather than random cells, which would yieldlittle useful information.
The ATM RMON draft specification also details two other collection methodsin addition to circuit steering, including the option to have cell-levelRMON instrumentation integrated in an ATM switch fabric.
Cisco and the six vendors with whom it worked to develop the ATM RMONspecification for the IETF, also plan to submit it to the ATM Forum laterthis year.
Cisco Systems (NASDAQ: CSCO) is the leading globalsupplier ofinternetworking solutions,including routers, LAN and ATM switches, dial-upaccess servers and network management software. These products, integratedby the
