Broadband Router V/S Ethernet Hub?

[casey.o]

Broadband Router V/S Ethernet Hub?
Whats the difference between them?

 

[Paul]

Broadband Router V/S Ethernet Hub?
Whats the difference between them?

A broadband router, listens to what is happening
on the switch side, and if a packet is destined for
some place other than the LAN, the packet is forwarded
to the WAN. So the router function is effectively
a single port. Additional ports are created with
the switch function. On my old ($300) Linksys router,
the switch+4LAN was on one circuit board, and the
router+WANport was on a second circuit board.
A cable ran between the boards, to tie them together.

---- LAN
--- WAN ---- router ---- Switch ---- LAN
---- LAN
---- LAN

An Ethernet hub on the other hand, is just the
switch portion. It keeps track of the MAC on
the port, to help understand where a packet
should be sent (MAC learning). And switches
can be built with more ports, or with mixes of
bandwidths on the same switch.

---- LAN
Switch ---- LAN
---- LAN
---- LAN

So in practice, you can take a one port router,
connect it to a switch, and make a four port product.

An example of a one port router, is the old BEFSR11.
One port is WAN and one port is LAN. That would be like the
BEFSR41 product, only the switch+4LAN printed circuit
board is missing.

http://www.fragtopia.com/reviews/linksys/befsr11detailed.jpg

And this would be the diagram of the BEFSR11. And it is
all ready to connect to one of the ports on a switch.

--- WAN ---- router ---- LAN

This is an eight port switch. You could connect the
BEFSR11 to one of the ports on this, and use the other
ports for your computers.

http://www.newegg.com/Product/Product.aspx?Item=N82E16833218023

When a switch has a WAN port and four LAN ports, it's
really like a five port switch, only the WAN connector
has reversed wiring compared to the LAN ports. So the
labeling of the ports, is so you use the correct
"straight-thru" or "crossover" cables. If a switch
doesn't label a particular port as WAN, then you can
use any port for that, just make sure you're using the
right kind of cable.

That's why I keep at least one cross over cable in the house.
If some new box needs a cross-over cable, I can test with it.
And if not, I can use one of my existing straight-thru cables.
The ADSL modem I bought, had the right kind of cable included,
so I could connect it immediately to my router. If instead, I
connect the ADSL modem straight to my computer, I end up using
a different cable. Such fun...

Paul

 

[Evan Platt]

Broadband Router V/S Ethernet Hub?
Whats the difference between them?

Generally a broadband router will have a dedicated "WAN" or Internet
port, and will often be able to make the necessary connection types -
PPPoE, etc. if needed.

A hub simply 'merges' all network devices connected to it.

Yeah, that may be oversimplifying things, but you can read a lot more
on wiki / google for broadband router vs ethernet hub.

 

[VanguardLH]

An Ethernet hub on the other hand, is just the switch portion.

A hub is not a switch. All traffic on all ports is subject to the CDMA
(collision) part of Ethernet. Any 2 hosts generating traffic will cause
a collision at the hub which means one of them will get ignored (require
a retry). A switch manages the collisions to determine if they can be
processed at the same time (within the multiplexing speed of the
processor). Doesn't matter if a port goes to an intranet host or to the
cable modem. You will get slower transfers using a hub (that's busy
with more than 1 port in) than a switch. A hub is a single "wire" to
which all ports are tapped into. It does afford the automatic handling
of cabling to properly align the data signal lines on the connections.
The hub replaced having to use vampire taps and other physical wiring to
hook hosts into the same segment wire. There is no traffic management
with a hub.

http://en.wikipedia.org/wiki/Ethernet_hub
http://en.wikipedia.org/wiki/Network_switch

What is the difference between an Ethernet hub and switch?
http://duxcw.com/faq/network/hubsw.htm

It keeps track of the MAC on the port, to help understand where a
packet should be sent (MAC learning).

Nope. A hub is just a wire to which the ports are connected. There may
be some signal noise reduction (reduce ringing) along with automatic
signal line alignment but it has no "smarts". You're talking about what
a switch can do.

And switches can be built with more ports, or with mixes of bandwidths
on the same switch.

Now you switched to switches. Besides more ports, they can be used to
separate network segments (to isolate traffic or hosts) and as repeaters
to get beyond the 100 meter max signal length. There used to be
repeater hubs but nowadays I think the cost differential would be
trivial from using a switch. In fact, finding a consumer grade repeater
hub might be very difficult but I can still find hubs and switches.

Hubs might still be cheaper but you might as well as get a switch.
Besides managing traffic between ports for overall faster transfer, you
can create segments in your network. For example, you can keep all QA
test traffic generated by hosts in the QA alpha lab inside that network
segment so it doesn't flood the corporate segment(s). You can assign
QoS (Quality of Service) settings to a port to give it priority over
other ports. Some hubs will note an upstream port that must be used
when you chain multiple hubs together (to increase the number of ports
within a network segment). Any port can be used in a switch to go to
the next switch and you can decide if all hosts are on the same segment
or different segments without having to change cabling. Can't do that
with a hub.

Switches have a processor so they run hotter than hubs. Hubs don't as
they're dumb connection devices. Switches need ventilation for the
processor. Hubs don't have a processor so there are no ventilation
holes. Think of an Ethernet hub like a USB hub: all ports are sharing
the same wire and nothing manages the traffic.

When a switch has a WAN port and four LAN ports, it's really like a
five port switch, only the WAN connector has reversed wiring compared
to the LAN ports. So the labeling of the ports, is so you use the
correct "straight-thru" or "crossover" cables. If a switch doesn't
label a particular port as WAN, then you can use any port for that,
just make sure you're using the right kind of cable.

That's why I keep at least one cross over cable in the house. If some
new box needs a cross-over cable, I can test with it.

I suppose an unpowered hub cannot have the active logic needed to
automatically realign the data signals if the wrong cable type is used.
I haven't used an unpowered hub in a long time (decades maybe) and
switches have to be powered. A powered hub and a switch (which requires
power for the processor) would do the automatic realignment. One of the
handy uses for a switch is not having to worry about which type of cable
you use. That concern is needed only if you connect one host's Ethernet
port directly to another host's Ethernet port. If instead you put a hub
or switch between them then the detection is automatic and the signals
gets passed or switched as needed. It's easier setup to run your hosts
through a switch or a router (whose frontend is a switch).