IBM SG24-4817-00 - Manual (Page 30)

This soft copy for use by IBM employees only.
2.3.1 Internal Features
The IBM 8285 Expansion Chassis has two primary internal features.
2.3.1.1 ATM Backplane
The IBM 8285 Expansion Chassis contains an ATM backplane that is effectively a
three-slot version of the 8260 hub
′
s ATM backplane. That is to say, it is a
completely passive backplane with female connectors. It is capable of
supporting most 8260 hub ATM modules.
Note
However, there are some differences between the ATM backplanes of the
IBM 8285 and IBM 8260. Specifically, the IBM 8260 ATM Control Point and
Switch Module cannot be used in the IBM 8285 Expansion Chassis. For more
information, refer to Chapter 3, “Functional Overview of the IBM 8285” on
page 17.
2.3.1.2 ATM Planar
The IBM 8285 Expansion Chassis contains a planar which has a switch-on-a-chip
switching module. When connected to the IBM 8285 Base Unit with the
expansion interface cable, the switch-on-a-chip performs all the port-to-port cell
switching:
• Between ports in the IBM 8285 Base Unit
• Between ports in the IBM 8285 Base Unit and ATM modules in the IBM 8285
Expansion Chassis
• Between ports on ATM modules in the IBM 8285 Expansion Chassis
2.3.2 Front Panel
Figure 6 shows the front panel of the IBM 8285 expansion unit.
Figure 6. Front Panel of the I B M 8285 Nways A T M Workgroup Switch Expansion Unit
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ATM Workgroup Solutions: Implementing the 8285 ATM Switch