Cabletron Systems 9E531-24 - Manual (Page 30)

Technical Overview
3-4
INB Interface
Each module attaches to both INB A and INB B and has two INB ASICs. The INB
ASICs use 64-byte Ethernet frames for transmission onto the INBs at 66 MHz.
The 9X5XX modules are fully compatible with the the first generation 9X4XX
modules. The first generation modules communicate only on INB B using a
56-byte canonical frame format, at 40 MHz. If the newer module detects a first
generation module on the backplane, it automatically changes from the fast
66 MHz Ethernet frames, to the first generation compatible 40 MHz canonical
frame on INB B only. INB A is used only by the 9X5XX modules and remains at
the higher speed.
i960 Core
The i960 core provides modules host services, the SNMP protocol stacks, to
support industry standard MIBs, as well as Cabletron enterprise extension MIBs
for each media type. Management services, such as telnet, WebView and network
address to MAC address mapping, are also provided by the i960 core.