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Madge LANswitch 3LS Multilayer Switch High-Performance Layer 3 Switching

The Madge LANswitch™ 3LS Multilayer Switch is a Layer 3 switch module that effectively provides the functions of a LAN router but several times cheaper and faster. It is the next logical stage for switching technology, which first replaced bridges (Layer 2) in LANs and is now advancing to handle the more complicated function of routers (Layer 3).
Quickly dominating today’s LAN environment, LAN switches provide the throughput and dedicated bandwidth necessary to support users’ ever growing network needs. New applications based on client/server technology, multimedia, and collaborative computing have all benefited from the speed, price and performance afforded by switching.   

Fast Layer 3 Switching

The Madge LANswitch 3LS allows communication between networks that is as fast as communication within the switched network
But LAN switches do not provide all the answers. In most networks, LAN switches must be used in conjunction with routers, and this has a major impact in a number of areas. Routers are significantly slower than switches. Networks combining two types of equipment are inevitably more expensive to implement. And moves and changes are much more complicated in router-based networks.

The Madge LANswitch 3LS Multilayer switch

  • Transforms LANswitch into a fully scalable, integrated system with Layer 2 and Layer 3 capabilities.
  • Integrates with the LANswitch backplane, which has interfaces to Ethernet, Fast-Ethernet, FDDI and ATM.
  • Costs about 20% of a traditional routing solution, but has the award-winning performance of LANswitch.
  • Performs both IP and IPX switching, unlike many other IP only systems.
  • Reduces or eliminates the need for expensive routers in the local network.
  • Is fully standards-based and interoperates with traditional routers, providing full investment protection.

Multilayer Switching

With the addition of the 3LS, LANswitch becomes a fully integrated multilayer switch providing wire-speed connectivity between IP and IPX workgroups and VLANs, while working with existing router-based network topologies and configurations.

Multilayer switching is an intelligent combination of switching and routing technologies that provides a complete and integrated solution for all kinds of LAN infrastructures. Unlike systems from other vendors, Madge multilayer switching is standards based, using no proprietary protocols, nor is it an IP-only technology.

Guaranteed Investment Protection

The LANswitch 3LS maintains the strong Madge tradition of investment protection and future-readiness. The 3LS fits into the customer's existing environment and can added to the network in a staged process to gradually reduce the load on routers and improve client/server performance.

The 3LS interoperates seamlessly with standard routers and Layer 3 elements such as TCP/IP stacks, and IPX servers and clients. It uses standard protocols only: Open Shortest Path First (OSPF) and Router Information Protocol (RIP).

The diagram shows two options for migrating to multilayer switching, with investment protection.

Logical Migration Path

In a conventional router-based network, building LANs connect via a router to a shared FDDI backbone. The routers in each building service both local and backbone traffic and can become a congested bottleneck. The diagram shows two possible solutions. The first option is for multilayer LANswitches to provide local routing to the buildings. This off-loads local traffic from the backbone router, and provides wire-speed Layer 3 switching to the building LANs. The second option also migrates the backbone to switched FDDI. The two 3LS modules share the load, while all the buildings benefit from multilayer switching. One router remains for WAN connectivity and complex internetworking.

Looking Under the Hood

The LANswitch 3LS plugs directly into the Cellenium™ Bus, giving it a multi-gigabit switching-speed routing throughput.

All time critical tasks such as packet forwarding are executed in fast VLSI hardware, and are separated from tasks such as route determination. Packets shoot across the switching fabric with a very low delay and at a speed that no router can match.

Even if there are many multilayer switches in the network, packets only have to pass through one of them to reach their destination. One hop routing translates directly into better network performance.

Redundancy and Load Sharing

It is not necessary to place a 3LS in each LANswitch hub, and it is this which makes it an especially cost-effective proposition. However, in order to guarantee uptime in a centrally located multilayer switch, a redundant 3LS module can be used.

In a network with widely dispersed switches, multiple modules can be used to share the workload and shorten data paths. 3LS modules can be configured to take on primary responsibility for one set of VLANs or subnets, and secondary responsibility for others.

Access Control

The LANswitch 3LS provides sophisticated access control to network devices for security purposes. The user can specify whether to forward or block packets, and can control access based on the station IP address, IP subnet, IPX network address and the application type (Telnet, FTP etc.). Filters are implemented using fast, custom designed ASICs, so that performance is unaffected.

Simplified Moves and Changes

A major limitation of some router-based networks is that IP addresses in end-stations have to be reconfigured when they are moved to a different LAN segment. VLANs make membership of logical networks independent of physical location. Madge has the tools to make the true logical network a reality.

Advanced VirtualMaster™ is a MultiMan™ application that makes it easy for network managers to automatically create and maintain VLANs based on IP and IPX addresses, while the 3LS performs fast switching between VLANs.

Integrated Management

MultiMan and SMONMaster™ make up an integrated management system that allow Layer 2 and 3 switches and hubs to be managed and monitored from a single console.

Unlike a router, the 3LS is simple to configure. 3LS View™ is a MultiMan add-on application for simple point-and-click configuration of the 3LS module.

Industry-Leading SMON Management

Comprehensive, integrated network management is the key to keeping switched enterprise networks running smoothly. Network managers must be able to obtain a real-time view of all switched traffic in order get a meaningful picture of network activity.

As part of the LANswitch product line, the 3LS is managed by the SMONMaster application which works in conjunction with MultiMan, Madge’s graphical SNMP-based Network Management System.

With SMONMaster you get a complete and accurate picture of backbone, workgroup and desktop traffic, from global views to port-specific perspectives. SMON™ technology allows traffic to be examined per VLAN. It alerts the network manager to problems at the highest level and enables problem isolation and in-depth examination.

MultiMan and SMONMaster are fully integrated with such popular management platforms as HP OpenView for UNIX, HP OpenView for Windows, and IBM NetView for AIX. SMON is in the process of becoming an industry standard.

Multiservices Ready

The LANswitch 3LS is designed for multiservice networks running data, voice and video applications. Exceptionally low, fixed latency and packet prioritization, together with LANswitch class performance make it ideal for the most demanding environments. It handles IP multicast packets, which are used in applications such as videoconferencing, by forwarding them to pre-defined VLANs.

Intelligent Bridging

Many organizations use IP and IPX in conjunction with other protocols. Some protocols are in fact non-routable so that ordinary routers are unable to deliver those packet types to a destination outside their own subnet or broadcast domain. LANswitch multilayer switches have the intelligence to deal with packets from non-routable and non-IP/ IPX protocols by bridging them to specific Virtual LANs rather than broadcasting them indiscriminately at Layer 2. The service is available for DECnet, NetBIOS, Apple Talk and LAT stations.

Customer Support Without Limits

The LANswitch 3LS Multilayer Switch is backed by Madge’s world-renowned expertise in networking. Madge’s premier service and support organization continues to satisfy the needs of our extensive installed base in the most demanding Global 1000 companies.

A worldwide network of field service engineers provides a wide range of technical services including on-site technical support and software upgrades. Customers can also download up-to-date technical information from on-line services such as CompuServe or can visit the Madge World Wide Web home page ( The LANswitch 3LS comes with a one year warranty and a 30-day installation guarantee, which includes free technical hotline support and on-site assistance as required.



Intel 80960 33Mhz RISC processor
2 Mbyte Flash memory
4 Mbyte DRAM


I/O Ports
2.56 Gbps
WAN ready
RS232, RJ45 connector, 9600 bps


IP, IP Multicasting RFC 1812
BOOTP client RFC 1542
Router to Router     RIP1, RIP2 RFC 1058, 1722-24


SNMP version 1
IP forwarding MIB
Interface table MIB RFC 1575
Intelligent Bridging     DECnet, NetBIOS, Apple Talk, LAT
(LANswitch bridges all MAC layer


Single 3LS
Multiple 3LS    
1.0 Mpps
1.9 Mpps
(64 byte frames)
Latency: 12 microseconds for a 64 byte packet


Dimensions (h,w,d):
Hub Slots:     266mm x 40mm x 230mm
Occupies two slots in hub
Consumption  4.5A @ 5V


Humidity:     0-40 degrees Celsius
5% to 95% non-condensing




FCC Part 15, subpart J, class A;
EN55022 class B; CE
Meets EN50082-1
Front Panel LEDs:Transmit, Receive
Port Activity
Error status
WAN link (for future use)


MultiMan for Windows version 5.2 or higher
MultiMan for UNIX version 4.1 or higher




LANswitch 3LS Multilayer Switch
Specifications subject to change without notice.


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