Telecom Routers Switches Question:

A switch, keeps a record of the MAC addresses of all the
devices connected to it. With this information, a switch
can identify which system is sitting on which port. So when
a frame is received, it knows exactly which port to send it
to, which significantly increases network response times.
And, unlike a Hub, a 10/100Mbps switch will allocate a full
10/100Mbps to each of its ports. So regardless of the
number of PCs transmitting, users will always have access
to the maximum amount of bandwidth. It's for these reasons
why a switch is considered to be a much better choice then
a hub.

Routers are completely different creatures. Where a hub or
switch is concerned with transmitting frames, a router's
job, as its name implies, is to route packets to other
networks until that packet ultimately reaches its
destination. One of the key features of a packet is that it
not only contains data, but the destination address of
where it's going.

A router is typically connected to at least two networks,
commonly two LANs or WANs or a LAN and its ISP's network
(ex. your pc or workgroup and EarthLink). Routers are
located at gateways, the places where two or more networks
connect. Using headers and forwarding tables, routers
determine the best path for forwarding the packets. Routers
use protocols such as ICMP to communicate with each other
and configure the best route between any two hosts.

A router will typically include a 4-to-8 port Ethernet
switch (or hub) and a Network Address Translator (NAT). In
addition, they usually include a Dynamic Host Configuration
Protocol (DHCP) server, Domain Name Service (DNS) proxy
server and a hardware firewall to protect the Local Area
Network (LAN) from malicious intrusion from the Internet.