Very Computer

I'm possibly missing something fairly obvious here, but what is the main
difference between a Dual Speed Hub and a switch?

If the answer is not a lot, why is there such a huge price difference?

For example, you can get a D-Link 8-port Dual Speed hub for about 200ukp but
a simple D-Link switch with 1 10b-T and 1 100b-T will set you back the same
amount.  If the Dual Speed hub offers the same functionality what's the
difference?

As I say, I'm probably missing something obvious, but I really can't see what
it is.

(The D-link Dual speed hub I'm looking at is the DSH-8
 http://www.dlink.com/hubs/dsh8.htm)

Thanks in advance,

Neil Burrows
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A switch can have BOTH 100Mbs devices and 10Mbs devies connected
simultaneously, and will do buffering and so far to keep from dropping
packets.

Also, a switch generally can support any two ports talking to each other at
full speed.  So, an eight port switch could support the worst case of 4
separate 100Mbs connections and not drop packets, giving you an aggregate
bandwidth of 400Mbs.  (I guess if you're talking full duplex, you could
potentially have an aggregate bandwidth of 800Mbs on a switch.)

With a hub, if one port is talking to another at full bandwidth, the other
ports will be unable to do anything because they will be broadcasting the
same "conversation" to ALL of the ports.  Therefore, the best case
aggregate bandwidth of the hub is 100Mbs, or maybe 200Mbs if it's full
duplex.

Later,
        Dale
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| Dale E. Martin |  Clifton Labs, Inc.  |  Senior Computer Engineer    |

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Quote:> Many of the dual speed hubs I've seen have a switch on them.  They can be a
> 10Mbs hub, OR a 100Mbs hub.  You could never plug in devices of two
> different speeds.  (Note that I didn't look at the link you posted.)

" Each port on the DSH-8 supports dual 10/100Mb speeds. The hub
 auto-negotiates the speed with the connected nodes and creates independent
 10Mb and 100Mb segments. The integrated switch handles translation and
 traffic flow between the two segments."

Which suggests that both speeds can be used at the same time?

Quote:> Also, a switch generally can support any two ports talking to each other at
> full speed.  So, an eight port switch could support the worst case of 4
[snip]
> same "conversation" to ALL of the ports.  Therefore, the best case
> aggregate bandwidth of the hub is 100Mbs, or maybe 200Mbs if it's full
> duplex.

Thanks for the info.

Neil Burrows
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