Operation Manual

VigorSwitch G1080 User’s Guide
19
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
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.