CSMA/CD queestion

[Mulligun]

Hello

I have one question about ethernet CSMA/CD:

The slot time is the time needed to send 512 bits BUT including the premble+SFD???

Becouse if slot time is 512-bit time NOT including the preamble then transmiter sends NOT all the smallest allowed frame during slot time couse the smallest frame have 512+56+8 bits total (with preamble & SFD) so it is 576 bits to send while slot time is only 512-bits.
Assuming that all it implies that collision may happen only during first 512-bits BUT INCLUDING the preamble! (so assuming the worst scenario the transmiter wolud konow about collision in the middle of data pool in the frame, but NOT later?)

Am i correct???
Please help!

 

[bkelly13]

I am not a heavy on ethernet communications but as there is no other reply I may have an answer. When a sender starts sending out an ethernet packet, the risk for colisison only exist until the first bit reaches the end of the local network. (Routers and the such do not extend a single segment for the purpose of collision.) Once the first bit has reached both far ends of the local segment, there is no further risk of collision. At that time, all computers residing on the local segment are aware that a packet is being sent and will not send until the current packet has been completed. The exact number of bits sent before a message is safe from collision depends on the length of the local segment.

You asked for numbers but I just gave a summary. Did I answer your question or did I miss the boat.