Chris Mathey wrote:
> steve szmidt wrote:
>> On Wednesday 31 May 2006 08:42, Chris Mathey wrote:
>>
>>> That's not exactly true. I have never seen a recent router with "hub"
>>> ports. a hub is not full duplex, hubs are just repeaters, every host
>>> connected see's every unicast and multicast. A switch know's every mac
>>> address that is plugged into itself and only sends unicast frames to
>>> the
>>> intended MAC address. Broadcast frames hit everything of course.
>>
>>
>> Well this is not correct. A hub differs from a switch in that it will
>> route traffic to all ports, much like a broadcast. While a switch
>> will route it only to the correct port, where it's internal notes
>> tracks what port each MAC (NIC) address uses.
>>
>> A hub is not a repeater, it's old technology from before switches
>> were invented. Once switches showed up they solved the problems of
>> collisions that the original hubs had.
>> An Ethernet network was designed to have collisions of packets, and
>> could in real life sustain about 30% of the traffic being collisions.
>> Passing 30% it degraded rapidly.
>>
>> The switch solved the problem neatly and has but all replaced the use
>> of hubs.
>>
>
>
>
> A hub is in other terms a "repeater" because when an ethernet frame
> enters one of its ports it "repeats" that frame to all other ports. It
> also amplifies the signal. In this environment (collision domain) the
> protocol CSMA/CD to detect collisions.
>
> Also a hub can only provide half duplex communication because a hub
> takes the signal from the active incoming port and immediately pushes
> the signal out on all outgoing ports at the same time after signal
> amplification. Because this is going on at the same time, a hub needs
> to do it in half duplex fashion.
>
> Basically my statement was that if you go buy a router from compusa
> netgear\dlink\linksys\et al they are switches and not hubs. The
> internal software creates a separate VLAN for the WAN port and routes
> between them.
>
> Chris
>
>
>
I would be interested to see if this is true. Of course, the
manufacturer is going to claim whatever is better, but it seems to me
that a consumer piece of equipment, like M$ itself, is going to be built
for rapid reproduction and profit rather than function. Like I said in
another response in this thread, I don't know. But, I'm speaking from
personal observation. Whether they claim "switch" or not, I believe
that the basic four-port routers that you see on the market are not
switches, but hubs.
--Michael
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