Cabletron Systems 9H42X-XX

Introduction

1-2

Each front-panel port (regardless of media type or bandwidth capability) can be

conﬁgured to operate in Full Duplex Switched Ethernet (FDSE) mode. FDSE

allows for each 10BaseT port to provide dedicated 20-Mbps bandwidth for

connections to ﬁle servers or high-end workstations, while 100BaseTX or

100BaseFX ports can be used to deploy fault-tolerant 200-Mbps backbone links.

All 100BaseTX ports also support auto-negotiation.

The 9H42x-xx modules support two types of packet switching:

•Traditional switching, which is 802.1d bridging based on physical layer address

information; it enhances the overall reliability of the network and, with DEC

Spanning Tree support, protects against loop conditions.

•SecureFast™ switching, which is high-performance switching based on source

and destination MAC (physical) layer addresses. Packets received from a

source address on a module’s protocol-dependent front panel network are

converted into ﬁxed-length, protocol-independent packets for transmission

across a backplane, and then are re-converted at the destination device into the

appropriate physical frame format for reception by the destination address.

Future ﬁrmware and management software enhancements will allow an

administratively deﬁned connection-policy between end stations connected to

SecureFast Packet Switching devices.

Each module also provides a single backplane interface to the INB bus, for

common transmission of data with all other modules of any media connected to

the INB in the chassis. The INB is the Cabletron-proprietary network bus for

protocol-independent, high-speed packet or cell switching between connectivity

modules that support front-panel Ethernet, FDDI, Token Ring, or ATM networks.

The connectivity modules incorporate Cabletron’s SecureFast Switch (SFS)

technology to provide high-performance packet switching based on source and

destination MAC addresses, rather than on internet protocol (IP) addresses. By

basing packet switching on physical layer information, the INB allows your

network infrastructure to be protocol independent. The INB backplane consists of

two channels (INB-1 and INB-2), each featuring a 64-byte wide data path capable

of a sustained data transfer rate of 2 Gigabits/second (4 Gigabits/second for the

combined channels); all 9H42x-xx modules connect to INB-2. The INB backplane

requires no management, as its data transmission is subject to hardware defaults.

NOTE

Firmware support for the SecureFast Virtual Networking (SFVN) feature of the

9H42x-xx family (which allows switching conﬁguration on a per-user level) is in the

early stages of release as this document is published; SFVN remote management will be

included in a future release of SPECTRUM Element Manager.