Lexmark IBM 9077 - Manual (Page 45)

Router Node 27
If the temperature exceeds 57.5 °C (137 °F), the GRF does an automatic
system shutdown.
• Hot-swappable fan
For the GRF 16S model, the cooling fan can be replaced while the GRF is
in operation.
• Hot-swappable adapters
There are two types of adapters on the GRF: the media adapters and the
IP Switch Control Board.
The media adapters are independent of each other and can be replaced or
removed without affecting any other adapter or the operation of the GRF.
However, the IP Switch Control Board is critical to the GRF. Should this
board be unavailable, the router fails.
• Crosspoint switch
The crosspoint switch is a 16x16 (16Gb per second) or 4x4 (4Gb per
second) crossbar switch for the GRF 16S and GRF 04S, respectively, see
Figure 12 on page 27. It is the I/O path used when the media adapters
need to communicate with each other.
Figure 12. GRF Architecture
Some parts in Figure 12 need to be explained:
User Interface
Dynamic Routing Engine (Route Manager)
Configuration/Control
............ ..........
CPU
QBRT
Tx
B
uf
fe
r
R
x
B
uf
fe
r
Serial Interface
Media Interface
RT
AT M
OC
-3 c
MM
Combus
80 Mb/s bus
Out-of-Band
4 Gb/s Switch
IP /S O N E T
OC
-3 c
MM
CPU
16MB Rx / 16MB Tx Buffers
Speed decoupling
WAN delays
QBRT Route Table Lookup
Times range from 1-2.5 µs
On-Board Processor
IP Header
Route decisions