RE: Kinda On Topic - network question

["Steve Morgan" <steve@xxxxxxx>]

A hub is a fairly dumb device that effectively has all the ports connected
together all the time. Any traffic on ANY port appears at EVERY port, so
all
devices on all ports are contending for the same bandwidth (10 or 100
megabits per second, depending on the hub).

A switch is rather more intelligent in that it can open multiple
point-to-point pathways between ports and allow data to flow at full speed
along those separate paths. Traffic coming in on one port only appears on
other ports if that's where it was supposed to go.

As an example, suppose you have 4 machines, A, B, C and D. With a hub, if A
and B are communicating at full speed, network performance will degrade for
machines C and D as well, because the network bandwidth is shared between
all the ports. Replacing the hub with a switch, A and B can continue to
communicate at full speed without impacting on C or D since the traffic
doesn't reach them. C and D can also now communicate at full speed and the
overall bandwidth has increased.

With a hub, the maximum throughput is determined by the network speed (10
or
100 Mbps). With a switch, the maximum _theoretical_ throughput is
determined
by the network speed * number of switch ports / 2.

However, if you have multiple clients communicating with a single server,
as
might be the case with a small network, performance will be constrained
because there is contention at the server port.

The biggest benefit will be realised upgrading your hub from 10Mbps to
100Mbps.

Hope that helps,
Steve

> -----Original Message-----
> From: Jon Bhargava [mailto:jonathan.bhargava@xxxxxxx]
> Sent: 13 September 2001 10:27
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] Kinda On Topic - network question
>
>
> Hi
>
> I need to upgrade my old 8-port network hub to something faster
> I have just seen a 16-port network 'switch' on the Scan site.
> Please can somebody excuse my ignorance & tell me the
> difference between a
> hub & a switch?
>
> Many thanks
>
> Jon Bhargava