Black Box LGB2002A-R2, User Manual

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User Manual
Publication date: September, 2007
Revision A3
31
Parameter
value/LAN
10Base 100Base 1000Base
Max. collision
domain DTE to
DTE
100 meters
100 meters for UTP
412 meters for fiber
100 meters for UTP
316 meters for fiber
Max. collision
domain with
repeater
2500 meters 205 meters 200 meters
Slot time
512 bit times 512 bit times 512 bit times
Interframe Gap
9.6us 0.96us 0.096us
AttemptLimit
16 16 16
BackoffLimit
10 10 10
JamSize
32 bits 32 bits 32 bits
MaxFrameSize
1518 1518 1518
MinFrameSize
64 64 64
BurstLimit
Not applicable Not applicable 65536 bits
Table 3-4 Ethernet parameters for half duplex mode
In full-duplex operation mode, both transmitting and receiving frames are
processed simultaneously. This doubles the total bandwidth. Full duplex is much
easier than half duplex because it does not involve media contention, collision,
retransmission schedule, padding bits for short frame. The rest functions follow the
specification of IEEE802.3. For example, it must meet the requirement of minimum
inter-frame gap between successive frames and frame format the same as that in
the half-duplex operation.
Because no collision will happen in full-duplex operation, for sure, there is no
mechanism to tell all the involved devices. What will it be if receiving device is busy
and a frame is coming at the same time? Can it use “backpressure” to tell the
source device? A function flow control is introduced in the full-duplex operation.