11 May 2000 10:22
> To: [EMAIL PROTECTED]
> Subject: Re: CSMA/CD : full duplex
>
> Further to my original post...
>
> It is possible to get collisions on a Full Duplex segment. Transmission
> from the switch towards the destination is a shared bandwidth domai
When Cisco says "Full Duplex", they typically refer
to the MAC layer function of transmitting and
receiving at the same time.
This is accomplished on ethernet by uncoupling the
Collision Detection circuit, and buffering TX and RX
in separate queues.
There is no internal 'CSMA/CD' in Cisco switch
Further to my original post...
It is possible to get collisions on a Full Duplex segment. Transmission
from the switch towards the destination is a shared bandwidth domain (with
other originating hosts transmitting towards the same destination). As such
collisions may occur on the transmit from
It is my understanding that the CSMA/CD function is handled by the switch
internally before the output frame is sent to the device.
We recently had a thread on late collisions that mentioned as a possible
source a NIC set to full-duplex that was connected to a half-duplex hub.
Since CSMA/CD was d
Title: RE: CSMA/CD : full duplex
As a side note, Full Dup and CSMA/CD are impossible to have together, since Full dup uses separate paths (wires) there can be no collisions.
===
Clayton Dukes
Sr. Network Engineer
Landstar System, Inc.
Jacksonville, FL
904-390-1109
http
Actually CSMA/CD is still required. When communicating through a switch,
the TX (towards the switch) is guaranteed the full bandwidth towards the
switch. However the inbound (RX from the switch) may be carrying traffic
from more than one originating host. As such, collisions may still occur if
Full duplex does not require CSMA/CD. Full duplex requires a switch.
Transmit and receive are done on separate wires to a switch. The switch
then performs all arbitration internally. This theoretically makes 200Mbps
possible, if the transmit and receive pipes are both kept full at 100Mbps
When using full duplex, both stations may transmit and receive simultaneously, so no
arbitration is needed. This is why collisions can't happen when using full duplex:
the transmission and reception circuits are completely separate, so collisions cannot
occur.
<< Sorry to ask such a simple qu
Full duplex transmission requires a point to point connection between two
devices. This is achieved using a switch. Since the connection is between
two and only two devices at a time, this allows them to transmit and receive
at the same time. Thus a collision would never occur and CSMA/CD is
un
Sorry to ask such a simple question--but the CCNA book
is still unclear as to what's going on.
Half-duplex ethernet uses CSMA/CD for arbitration on
the link. Does full duplex use it as well for
arbitration? The book makes it sound like if you are
running full-duplex that the CSMA/CD is not necess
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