Hub vs switch 100mb

Danh

If you are plugged into a switch, I know you will get 100mb on each port (provided all your cabling and NICs are at least 100mb capable).

What happens when you're plugged into a 10/100 hub? Does each port still get 100mb? Or is the 100mb shared amongst the ports?

thanks

Webmaster

Or is the 100mb shared amongst the ports?

Yes, it is shared. But when deciding whether you should implement a hub or switch you should realize that usually not all stations attached to a hub transmit simultaneously.

Danh

Thanks a lot

Webmaster

You're welcome

Danh

I understand how the bandwidth can be shared amongst all users connected to a hub. Say 100mb hub with 10 users connected. The hub gives each user 10mb?

I just read that when the same users are plugged into a switch, they each have a 100mb connection. How is this possible?

remyforbes777

The way this is obtained is because when a 100 mb hub is used, the hub transmits data to all the nodes connected to the hub, sending data to all data on the hub splits the bandwith. A switch on the other hand uses the MAC address and keeps track as to what port the corresponding node is connected thus dedicating all the bandwith to just that node. So basically if I have computer and I send out data through the hub, in order to find the specific computer it has to transmit to all the nodes connected at the same time splitting 100/10 = 10. If i have a computer and send out data through a switch, the switch keeps a data base of the computers MAC address and the port its connected to and sends only to that port, thus committing all bandwith to that node.

remyforbes777

A good analogy of this is, say you are a person and you need to deliver a letter. You know the address and street but unforunately the houses on that street dont have any visible addresses. You give it to a postal worker (hub) and now he has to deliver the letter to the specific individuals house. He knows the street but he doesnt know the address. There are 10 houses on the street and none of the housees have visible addresses, so he would basically have to go to almost every house to find the one specific house. Now what if there was one postal worker that had a map of all the houses and the addresses related to every unmarked house(switch) . That post office worker could go and consult his map and be directed to the exact house thus cutting the time he has to search all the other houses thus speeding up the delivery of the letter. Hope that was an ok analogy.

skully93

remyforbes777 wrote:

A good analogy of this is, say you are a person and you need to deliver a letter. You know the address and street but unforunately the houses on that street dont have any visible addresses. You give it to a postal worker (hub) and now he has to deliver the letter to the specific individuals house. He knows the street but he doesnt know the address. There are 10 houses on the street and none of the housees have visible addresses, so he would basically have to go to almost every house to find the one specific house. Now what if there was one postal worker that had a map of all the houses and the addresses related to every unmarked house(switch) . That post office worker could go and consult his map and be directed to the exact house thus cutting the time he has to search all the other houses thus speeding up the delivery of the letter. Hope that was an ok analogy.

Quite! I like that a lot!

crabeater

All this seems different from the device I have. I was given a "10/100 Intelligent Switch", loaned 2 10Mb NIC's, and bought 2 100Mb NIC's.

When I attached all of them (4 computers) to the switch, indicator LEDs noted the fast NICs were transmitting at 100Mb, and the slow at 10Mb.

It would seem that the device is using "store-and-forward" mode so that each port is using its fastest possible speed. (I have no documentation)

Would this not support a theory that they were not having to share bandwidth? Though clearly if a central server was talking to these devices "at the same time" (one 100Mb was setup as a 2K server, but only Windows Explorer ever did multiple access, so I was not in control and had no way to measure bandwidth usage) it would have to spread its time among them, decreasing aggregate bandwidth per node as each would wait its turn to recieve data from the sever. But EACH was, from the switch, running at either 10Mb or 100Mb as the NIC in the computer allowed?

Also, I have a book (ILT Network + coursebook, page 6-30) that says that each port can run at different speeds, exactly as I am stating. It gives a similar example: a server on one 100Mb port & students on other 10Mb ports of the same switch. The students would all see their data transmit at full speed as the server port was running faster than the aggregate speed of the other ports.

(I will try to contact the guy that gave me the switch & see if he has a book. The device has no manufacturer (CISCO, NETGEAR, etc) name on it, inside or outside.)

lazyart

Your switch is doing exactly what it is expected to do. If it senses a 100Mb connection it will use it to it's fullest.

Fu Loser

skully93 wrote:

remyforbes777 wrote:

A good analogy of this is, say you are a person and you need to deliver a letter. You know the address and street but unforunately the houses on that street dont have any visible addresses. You give it to a postal worker (hub) and now he has to deliver the letter to the specific individuals house. He knows the street but he doesnt know the address. There are 10 houses on the street and none of the housees have visible addresses, so he would basically have to go to almost every house to find the one specific house. Now what if there was one postal worker that had a map of all the houses and the addresses related to every unmarked house(switch) . That post office worker could go and consult his map and be directed to the exact house thus cutting the time he has to search all the other houses thus speeding up the delivery of the letter. Hope that was an ok analogy.

Your postal worker would not have to go to every house to fidn the address. Your postal worker would simple make a copy of every package and drop it off at every house.

Switch anology is correct tho.

remyforbes777

Thanks, I see what you are saying. I gave it a shot.

Fu Loser

It is a great analogy!

I just don't want you to have that in your head to long that you get stuck thinking that.

Damn straight you gave it a shot, and we all appreciate that you did

Now theirs a new analogy everyone can use