CCNA Class Day 2-

The Hardware Part of Computer Internetworking by Layer (Today layer 1 the physical layer.)

Cabling

10base5 – Thicknet- up to 10 Mbps – up to 500 meters – Co-axial cable-it is the backbone of a BUS network. A very large thick cable. Connected to the computers via a transceiver. The transceiver is connected to the cable via a Dracula Vat. You must “cap” or “terminate” the end of the bus. This cap will have a very specific resistance to help eliminate echo collisions. If the cap is missing or if there is any cut in the cable the entire network will go down

10base2 – Thinnet - up to 10 Mbps – up to 200 meters – Co-axial cable - it is thinner and easier to handle than thicknet.

Net-admin 5-4-3 rule: You can have a max of 5 segments in a network; a minimum of 4 repeaters, only 3 of the 5 segments can have computers, a max of 30 pcs per segment.

UTP- unshielded twisted pair – 8 wires, 4 sets of pairs

More…

10baseT – up to 10 Mbps – up to 100 meters – UTP - can now use a hub and move to a star topology, so if you loose one segment the rest of the network stays up.

10baseF – up to 10 Mbps – Fiber optics

Hub – a physical layer device for connecting different segments of a network, Replaces a repeater.

Wireless

802.11b – 11Mbps

802.11g – 54Mbps

Connectors

BNC – British Naval Connector

RJ45 – Registered Jack

Crimping

Straight Cable: used to connect two different types of devices or ports.

Cross Over Cable: used to connect two similar types of devices or ports.

Rollover Cable: This is a special purpose cable, like connecting a PC to the console port of a router. Pin 1 is mapped to Pin 8, 2 to 7, 3 to 6, 4 to 5, 5 to 4, 6 to 3, 7 to 2, and 8 to 1.

Cable Pin Outs
Straight Cable Pin OutCrossover cable

DTE – Data terminating equipment

DCE – Data Commutation equipment

What we will go over in the next class

Data link layer

Arcnet

Token ring

Ethernet

Token Bus

FDDI