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Home > Archive > alt.certification.cisco > April 2004 > half-duplex collision question
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half-duplex collision question
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| Ticking Timebomb 2004-04-20, 11:26 am |
| 1)Half-duplex Ethernet operates in a shared collision domain.
or
2)Half-duplex Ethernet operates in an exclusive collision domain
Which statement is true? By the nature of half-duplex, I would think 2, but
a study guide is telling me 1. Can anyone explain?
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| "Ticking Timebomb" <ticking.timebomb@sbcglobal.net> wrote in message news:<_0ahc.53255$3c3.22338@newssvr25.news.prodigy.com>...
> 1)Half-duplex Ethernet operates in a shared collision domain.
> or
> 2)Half-duplex Ethernet operates in an exclusive collision domain
>
> Which statement is true? By the nature of half-duplex, I would think 2, but
> a study guide is telling me 1. Can anyone explain?
half-duplex cannot send and receive at the same time because of
collisions...like hubs for instance....CSMA/CD
switches -full-duplex ...send and receive at the same time..because
switches send known unicasts out one port...
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| Personally I think they both could be correct since half or full-duplex is
not necessarily determined by whether it's a switch or hub.
A hub is always half-duplex which would make 1 correct. But a switch can
operate in either half or full-duplex, so with a switch it would be 2.
It all depends on the equipment, not the mode of operation.
"Ticking Timebomb" <ticking.timebomb@sbcglobal.net> wrote in message
news:_0ahc.53255$3c3.22338@newssvr25.news.prodigy.com...
> 1)Half-duplex Ethernet operates in a shared collision domain.
> or
> 2)Half-duplex Ethernet operates in an exclusive collision domain
>
> Which statement is true? By the nature of half-duplex, I would think 2,
but
> a study guide is telling me 1. Can anyone explain?
>
>
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| paraag 2004-04-20, 2:25 pm |
| hi,
i am not sure but it may be like this-
half duplex means the data can be transmitted in both directions
..thereis no set diesction for data transmission.So it means that both
the sides are sharing that collision domain.
"Ticking Timebomb" <ticking.timebomb@sbcglobal.net> wrote in message news:<_0ahc.53255$3c3.22338@newssvr25.news.prodigy.com>...
> 1)Half-duplex Ethernet operates in a shared collision domain.
> or
> 2)Half-duplex Ethernet operates in an exclusive collision domain
>
> Which statement is true? By the nature of half-duplex, I would think 2, but
> a study guide is telling me 1. Can anyone explain?
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| mhenawy 2004-04-20, 3:15 pm |
| the answer is the 1st one it work on shared collesion domain since hubs work on the half duplex way , all are sharing the same bus (collison domain ) and one can send at a time so they all share it u'll find the question in testking and also the transcender version 3
thanks  | |
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"Ticking Timebomb" <ticking.timebomb@sbcglobal.net> wrote in message
news:_0ahc.53255$3c3.22338@newssvr25.news.prodigy.com...
> 1)Half-duplex Ethernet operates in a shared collision domain.
> or
> 2)Half-duplex Ethernet operates in an exclusive collision domain
>
> Which statement is true? By the nature of half-duplex, I would think 2,
but
> a study guide is telling me 1. Can anyone explain?
>
>
I think 2 is correct - in half duplex only one side is supposed to be able
to send data, but i'm not 100% sure.
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| The answer is both. But if posed this question in an exam I would answer 1
as being the most correct.
Half duplex mode means the device can either send or recieve but not at the
same time.
In a shared colision scenario full duplex can not work as the sending and
recieving frames would collide.
This setup is found with hubs or older base2, base5 coax buses.
In an exclusive collision domain. 2 devices such as PC's, switches, routers
(not hubs) are connected directly together and have seperate transmit and
recieve pairs. It is this reason that a device could use full duplex but
older kit that only supports half duplex could still be used but the other
device at the end of the cable would have to be configured to either half
duplex or auto-detect.
hope this helps
Toby
"Ticking Timebomb" <ticking.timebomb@sbcglobal.net> wrote in message
news:_0ahc.53255$3c3.22338@newssvr25.news.prodigy.com...
> 1)Half-duplex Ethernet operates in a shared collision domain.
> or
> 2)Half-duplex Ethernet operates in an exclusive collision domain
>
> Which statement is true? By the nature of half-duplex, I would think 2,
but
> a study guide is telling me 1. Can anyone explain?
>
>
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| forbesl 2004-04-21, 9:28 am |
| The answer is 1. Here's why:
When they speak of "half-duplex ethernet", they are talking about a network of computers connected to a hub or group of hubs
(not ethernet switches). Because hubs operate at half-duplex and a computer connected to a hub broadcasts to all other computers connected to that hub, they all share the same collision domain.
Yes, "half-duplex" could mean any computer configured for half-duplex operation, or any single switch port configured for half-duplex. However, combined with "ethernet", they are speaking of a topology, not just a duplex mode. |
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