Question

i) what are the major differences between LAN and WAN? ii) what are standards in data communication? iii) what are the two categories of standards in data communication?

Answer 1

i) 1.LAN stands for Local Area Network.Whereas WAN stands for Wide Area Network.

2.LAN’s ownership is private.But WAN’s ownership can be private or public.

3.The speed of LAN is high(more than WAN).While the speed of WAN is slower than LAN.

4.The propagation delay is short in LAN.Whereas the propagation delay in WAN is long(longer than LAN).

5.There is less congestion in LAN(local area network).While there is more congestion in WAN(Wide Area Network).

6.There is more fault tolerance in LAN.While there is less fault tolerance in WAN.

7.LAN’s design and maintenance is easy.While WANS design and maintenance is difficult than LAN.

8.LAN covers small area within the building.While WAN covers large geographical area.

9.LAN operates on the principle of broadcasting.While WAN works on the principle of point to point.

10.Transmission medium used in LAN is co-axial or UTP cable.Whereas WAN uses PSTN or satellite link as a transmission or communication medium.

ii) Standards :-

Data Communication Standards Layer Common Standards 5. Application layer HTTP, HTML (Web) IMAP POP (e-mail) 4. Transport layer rt layer TCP (Internet) SEX NovellLAN TCP (Internet) 3. Network layer IP (Internet) TENNE 2. Data link layer Ethernet (LAN) PPP (dial-up via modem for MAN) 1. Physical layer Category 5 twisted pair (LAN) Fiber optic cable (WAN)

iii) Categories of Data Communication Standards
1. De jure standards – those that have legislated by an officially recognized body
2. De facto standards – can be further subdivided into
classes: proprietary and non-proprietary. Proprietary
standards are those originally invented by a commercial organization as basis for operation of its products. Nonproprietary standards are those
originally developed by groups or committees that
have passed them into the public domain.