NETWORKING Interview Questions

Cables uses in networking

2011-10-03T12:51:00.000-07:00

We have different cables as option in wired medium .

The following sections discuss the types of cables used I networks and other related topics.

· Coaxial Cable

· Twisted pairs (Unshielded Twisted Pair (UTP) and Shielded Twisted pair (STP) Cables)

· Fiber Optic Cable

Coaxial Cable

Coaxial Cabling has a single copper conductor at its center .A plastic layer provides insulation between the center conductor ad a braided metal shield. The metal shield helps to block any outside interference from florescent lights ,motors ,and other computers .

Unshielded Twisted Pair (UTP) Cable

Unshielded Twisted Pair (UTP) is the most popular and is generally the best option for local networks

Categories of Unshielded Twisted Pair

Type	Use
Category 1	Voice Only (Telephone Wire)
Category 2	Data to 4 Mbps (Local Talk)
Category 3	Data to 10 Mbps (Ethernet)
Category 4	Data to 20 Mbps (16 Mbps Token Ring)
Category 5	Data to 100 Mbps(Fast Ethernet)

Shielded Twisted Pair (STP) Cable

A disadvantage of UTP is that it ma6y be susceptible to radio and electrical frequency interference. Shielded twisted pair (STP) is suitable for environment with electrical interference; however, the extra shielding can make the cables quite bulky. Shielded twisted pair is often used on network using Token Ring.

Fiber Optic Cable

Fiber optic cabling consists of a center glass core surrounded by several layers of protective material. It transmits light rather than electronic signals eliminating the problem of electrical interference. This makes it ideal for certain environments that standard for connecting networks between buildings, due to its immunity to the effects of moisture and lighting.

Comparison between Wired and Wireless

2011-10-02T12:48:00.000-07:00

We have several choices regarding selection of media .Broadly we have following type of media

1. Guided of wired

2. Unguided or wireless

Comparison between wireless and wired is worth considering while selecting them as appropriate media .While wired considered more aesthetic from the point of security the wireless medium provides freedom of mobility .It lot depends on the environment and other conditions while choosing between wired and wireless .

Types of wired medium includes

· Copper

· Fiber

Although copper is cheaper and easy to install as well as maintain ,Fiber is expensive and is difficult to install and maintain .Fiber provides much faster as compared to copper ,which makes it ,preferred choice for large networks.

ROUTERS

2011-10-01T08:47:00.000-07:00

Router breaks both Collision domain as well as broadcast domain

A router translates information from one network to another;

Routers select the best path to route a message ,based on the destination address and sources address. The router can direct traffic to prevent head on collision, and is smart enough to know when to direct traffic along back roads and shortcuts.

While switches know the addresses of all computer on each side of the network ,routers understand the addresses of computers ,switches and other routers on the network .Routers can even “listen” to the entire network to determine which section are busiest –they can then redirect data around those section until they clear up .

If you have a LAN that you want to connect to the internet , you will need to purchase a router. In this case ,the router serves as the link between the information on your LAN and the Internet .It also determines the best route to send the data over the internet .Routers can:

Direct signal traffic efficiently
Route data between ant two protocols
Route data between linear bus ,star ,and star-wired ring topologies
Route data across fiber optic ,coaxial ,and twisted-pair cabling

What is a Network?

2011-09-30T11:45:00.000-07:00

In computer world the term network describes two or more computers that are linked in order to share recourse (such as printer and CD-ROMs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites or infrared light beams.

Networks can be classified in several ways common ones include

1. On the basis of area covered like LAN and WAN.

2. On the basis of relationship among entities like workgroup or client server.

The two basic types of Networks include:

Local Area Network (LAN)

Wide Area Network (WAN)