HUBS & SWITCHES: WHAT FOR ART THOU? By Wayne Sheppard ETEC 562

HUBS & SWITCHES DEFINED These simple, affordable but effective small boxes provide a central connection point for the networking of multiple computers. Hubs – small, simple, inexpensive devices that join multiple computers together at a low- level network protocol layer. Switches-same as hubs, except they operate with additional intelligence above that offered by hubs.

Some Characteristics of Hubs Require bandwidth to be shared while switches offer a dedicated connections Hubs can be managed or unmanaged Hubs are sometimes referred to concentrators A hub is a multi-port repeater

Managed vs. Unmanaged Managed hubs are usually not for home use. They have special networking computers built into them that do things that you will not need at home or small office. They are also more expensive than switches. Unmanaged hubs and switches are simple devices that let your Ethernet devices talk to each other.

Three Types of Hubs Passive-These hubs only restrain data Active Hubs-They amplify the signal before it is retransmitted Intelligent Hubs-These hubs are stackable and typically include remote management support via SNMP, and virtual LAN(VLAN) support

10/100 Ethernet Hub A 10/100 mbps is a good choice for basic home networks. The 10Mbps and 100Mbps devices communicate at different speeds, and the hub allows them to talk. Prices have come down to under $50, the versatility and speed of these hubs cannot be beat for the price. However, hubs are half duplex-each client can only send or receive date at a particular time.

SWITCHES Work on layer 2 of the OSI model. Only forwards data to specific network segment. This results in multiple, smaller collision domains, and more efficient bandwidth usage.

10/100 Ethernet Switch A 10/100 Ethernet switch can be considered a faster version of the 10/100 hub. Switches allow your Ethernet cards to operate in full duplex instead of half duplex. Full duplex means you can send and receive data at the same time. Switches also route traffic directly between ports instead of directing traffic across all ports. This means that each port on a switch gets dedicated bandwidth instead of shared bandwidth.

PORT NUMBERS? Where port numbers are concerned, consider an analogy between computer and the telephone. Port numbers and their associated network addresses work something like telephone numbers and associated extensions. A port number identifies both a computer and also a “channel” within that computer where network communication will take place.

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