IBM 8270, Installation And Service Manual

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Chapter 1. Physical Characteristics and Features
The IBM 8270 Nways Token-Ring LAN Switch is a member of and fully compatible
with the 8270 family of LAN switches, which includes the 8272 Nways Token-Ring
LAN Switch, Models 108 and 216, and the 8272 LAN Switch Modules, Feature
Codes 5208, 5308, 6208 and 6308, for the IBM 8260 Nways Multiprotocol
Switching Hub and 8265 Nways ATM Switch.
The 8270 provides high-speed forwarding of Token-Ring frames among the shared
or dedicated Token-Ring segments attached to each of the 8270 ports. The 8270
creates multiple, concurrent paths among the connected segments, each supporting
the full, 16-Mbps Token-Ring bandwidth. The 8270 also supports ATM uplink
connections.
The 8270 forwards Token-Ring frames among multiple, shared or dedicated,
Token-Ring LAN segments. Using a frame-forwarding technique similar to that of a
multiport, Token-Ring transparent bridge, the 8270 uses both Token-Ring MAC
addresses and source-route descriptors to forward Token-Ring frames from one of
its ports to another.
Figure 1-1. The IBM 8270 Nways Token-Ring LAN Switch Model 800 and 600
The 8270 is a rack- or surface-mount chassis that provides slots for one
Token-Ring Processor Card and up to six (for the 8270-600) or eight (for the
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Copyright IBM Corp. 1998
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