News Release

Cisco Systems Helps Network Managers Build Fault Tolerance, Redundancy Into ATM Networks

New software and hardware advances will speed deployment of
Aug 13, 1996

New software and hardware advances will speed deployment of ATM

SAN JOSE, Calif. - Aug 13, 1996 - Cisco Systems, Inc. today announcedsignificant new software and hardware advances for building fault toleranceand redundancy into LAN Emulation (LANE)-based ATM networks. These advanceswill give customers a highly reliable, standards-based ATM LAN Emulationsolution for production environments. They include:

  • Cisco's LANE Simple Server Redundancy Protocol (SSRP), a Cisco Internetwork OperatingSystem (Cisco IOS(tm)) for ATM software protocol. LAN Emulation SSRPprovides redundancy for all of the server components in LAN Emulation - theLAN Emulation Configuration Server (LECS), the LAN Emulation Server (LES)and the Broadcast and Unknown Server (BUS).

  • Cisco's Hot Standby Router Protocol (HSRP) for LAN Emulation. This willgive customers inter-Virtual LAN (VLAN) router redundancy in LAN Emulationbackbones. Both HSRP and SSRP can interoperate with any standard LANEmulation 1.0 client.

  • A new version of the ATM LAN Emulation module, with dual physical-layerinterfaces, for Cisco's Catalyst 5000 multi-layer LANswitch. The new module provides link redundancy, allowing a networkadministrator to connect a single uplink to two ATM switches, similar to adual-homing configuration, without consuming multiple uplink ports.

  • Cisco's standards-based Private Network-to-Network Interface (P-NNI)software enables multiple, redundant ATM links to be configured betweenswitches. P-NNI, the ATM Forum-specified call routing protocol, detectsnetwork loops and ensures only one path is used per ATM connection. Thisallows network administrators to load share their traffic over multiple ATMlinks while ensuring the remaining links act as backups should another linkbecome disabled.

"Users connected to our ATM network must always be able to reach theirdefault router to other VLANs and to the Internet," said Allen Robel, seniornetwork planner at Indiana University in Bloomington. "HSRP for LANEmulation provides quick cut-over to a backup router, allowing us to deploya highly survivable infrastructure, which is transparent to the user.Cisco's SSRP and Dual Phy LANE Module for the Catalyst 5000 will furtherstrengthen this environment with LANE service and physical link redundancy."

Eliminating single points of failure

Relying upon standard mechanisms already defined for LAN Emulation clientsin the ATM Forum's LAN Emulation specification 1.0, Cisco Systems developedSSRP to ensure that neither the LECS nor LES / BUS components would becomesingle points of failure in ATM LAN Emulation networks. LAN Emulationclients use these servers for important functions such as LAN address-to-ATMaddress resolution and forwarding broadcast and multicast traffic over anemulated LAN. However, the ATM LAN Emulation 1.0 specification onlyspecifies one set of these servers per emulated LAN / VLAN, thusrepresenting a potential single point of failure.

"Cisco's SSRP protocol allows network managers to deploy multiple LECS andLES / BUS components in a backup scheme for a given set of emulated LANs,"said David Benham, senior ATM product manager at Cisco Systems. "And,customers will have complete freedom to deploy any standard ATM LANEmulation 1.0 clients in their network, including those from Cisco's ATMInteroperability Partners.

Cisco has been working with its ATM Interoperability Partners, and withother ATM adapter vendors who support standard ATM Forum LAN Emulationclients, to ensure interoperability. Adaptec, Inc., Efficient Networks,Inc., Interphase Corporation, Olicom, Sun Microsystems and ZeitNet have orwill exploit the capabilities of Cisco's LAN Emulation redundancy solution.Cisco and these partners also have outlined which options in the LANEmulation 1.0 specification should be implemented to utilize Cisco's SSRP inenvironments that are not yet running the Private Network-to-NetworkInterface (P-NNI). [The outline of options now is available to any developerof LAN Emulation 1.0 clients at]

The Hot Standby Router Protocol, originally introduced by Cisco in 1994 forpacket- and frame-based networks, will provide inter-VLAN router redundancyfor ATM LAN Emulation networks. If two or more routers are connected to anemulated LAN, Cisco's HSRP allows one of those routers to monitor the statusof the other and take over the functions of that router should it becomeunavailable. HSRP over LANE operates transparently to hosts that must reachtheir inter-VLAN router.

Cisco's HSRP for LAN Emulation and the LANE Simple Server RedundancyProtocol will be part of a Cisco IOS software release available inSeptember. The new, dual physical-layer ATM LAN Emulation Module will shipin October. It is priced the same as the single physical-layer version.

Cisco Systems (NASDAQ: CSCO) is the leading globalsupplier ofinternetworkingsolutions for corporate intranets and the global Internet.Cisco's products, including routers, LAN and ATM switches, dial-up accessservers and network management software, are integrated by the Cisco IOSsoftware to link geographically dispersed LANs, WANs and IBM networks.Company news and product/service information are available at World WideWeb site is headquartered in San Jose, California.

For more information on the LAN Emulation solutions provided by Cisco's ATMInteroperability Partners, please contact:

Adaptec, Inc. EricBrown (408) 957-6645
Efficient Networks,Inc. Lori Hicks (214) 991-3884
InterphaseCorporation Mike Eckley (214)654-5325
Olicom BobCicciarella (214) 516-4658
Gordon Woode, Simon/McGarry Pub. Rel. (413)367-0104
TorkilOelgaard 011-45-45-27-01-98
Sun Microsystems JudyDepuy (415) 786-4468
ZeitNet George Marshall (408)986-9100

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