week 5: c0mputer netw0rking

C0mputer netw0rking is the c0nnecti0n with 0ne t0 ant0her c0mputer t0 enable them c0mmunicate each 0ther. C0mputer netw0rk als0 as the way t0 share hardware, s0ftware and data as well as t0 c0mmunicate with 0ne an0ther. There are a few 0f netw0rk classificati0n which is LAN, WAN, MAN, PAN and s0 0n.

LAN is sh0rt f0rm fr0m L0cal Area Network. It is work as a c0vers relatively small g0egraphical such as in a h0me, sch0ol and 0ffice area.

WAN is Wide Area Netw0rk were covers large ge0graphical area. It consist 0f tw0 0r m0re LAN c0nnected t0gether using c0mmunicati0ns techn0l0gy internet is the largest WAN.

MAN is Metr0p0litan Area Networks. The netw0rk design t0 service a metr0p0litan area like a city. It was c0nsist 0f multiple LAN and the size is between LAN and WAN.

PAN is a Pers0nal Area Netw0rk. It is w0rked as a pers0nal device like printer, m0bile devices and s0 0n. The way netw0rk are w0rking is thr0ugh wired 0r wireless.

0n the netw0rking, there are have s0me c0mp0nents t0 make c0mputer w0rk as well. The c0mp0nents can be categ0ries:

1. Terminals, w0rkstati0ns, c0mputer and 0ther devices (end c0de)

1. Data s0urces and destinati0ns
2. Example is pers0nal c0mputer, terminal, w0rkstati0ns, c0mputers and aut0matic teller machines.

2. transmissi0n Media (f0r transmitting data and c0ntr0l signals)

1. Transmit data in a netw0rked envir0nment.
2. Divided by 2 types

                   i.      B0unded/guided: twisted pair, c0axial, fibre 0ptics

                   ii.      Unb0unded/unguided (air/vacuum): satellite c0mmunicati0n, micr0wave radi0, infrared signals

3. s0ftware t0 c0ntr0l data transmissi0n

1. Inf0rmati0n, data 0r pr0gramming used-c0mmunicate/c0nnect t0 0ne and an0ther.
2. share inf0rmati0n

4. netw0rk electr0nics (intermediate devices f0r r0uting data fr0m s0urce t0 destinati0n)

1. Act as interface between different transmissi0n media/c0mmunicati0n pr0t0c0l
2. Example: hub, r0uter,switch, bridge, gateway.

• HUB :
•  device f0r c0nnecting multiple internet device t0gether and making them act as a single netw0rk segment.
• has multuple input/0utput p0rts
• w0rks at the physical layer 0f the OSI m0del

• ROUTING
• pr0cess 0f selecting paths in a netw0rking al0ng which t0 send netw0rk traffic.
• perf0rmed at teleph0ne netw0rk (circuit switching), electr0nic data netw0rks and transp0rtati0n netw0rks.
• the functi0n :
• manage the part al0ng which inf0rmati0n is f0rwarded within a netw0rk; facilitate c0mmunicati0n between c0mputers and internet.
• c0me in tw0 types: dynamic and static.
• dynamic is manage data traffic acr0ss the netw0rk; manage by r0uting pr0t0c0l.
• static is manuaaly c0nfigured by a netw0rk administrat0r wh0 pr0grams all 0f the necessary r0utes that are needed f0r data packets.

• GATEWAY
• called pr0t0c0l c0nverters, 0perate at any netw0rk layer.
• essential feature 0f m0st r0uters, alth0ugh 0ther devices can functi0n as a gateway

• BRIDGE
• device that f0ll0w the c0mputers 0n individual netw0rks 0r separate parts 0f a netw0rk t0 exchange inf0rmati0n.
• used t0 c0nnect a sma;; number 0f individual netw0rks t0 w0rk t0gether as 0ne large netw0rk.
• split an 0verl0ad netw0rk int0 small parts

• PRIVATE BRANCH EXCHANGE (PBX)
• swicth stati0n f0r teleph0ne systems
• c0nsists mainly 0f several branches 0f teleph0ne systems and its swicth c0nnecti0ns t0 and fr0m them.
• the functi0n:
• pr0vide 0ne single number taht external callers can use t0 access all pers0ns in a c0mpany
• distribute calls t0 empl0yerd in a answering team in an even way; using the Aut0mate Call Distributi0n (ACD) feature.
• all0w the user 0f cust0mized business greetings.
• pr0vide system call management features.
• transfer calls between internal extensi0n.

• BLUETOOTH VS INFRARED
• bluet0oth:
• wireless and aut0matic and 0ffers users with variaties 0f excellent features that has recreated the art 0f c0nnecti0n
• bluet0oth techn0l0gy w0rks by transmitting signals via l0w frequency radi0 signa
• the part 0f  c0mmunicati0n is appr0ximately w0rking 0n 2.45 gigahertz.
• the standard range is ar0und ten meters
• many  ways have c0ntributed much in c0nnecting individual systems with0ut being b0thered by bulk 0f the cables and wires.
• 
  
• infrared:
• 0ne t0 0ne pr0cess
• transmit  signals between the tw0 but n0t with an0ther separate system.
• w0rks 0nly 0n the line 0f sight principle where in 0ne has t0 p0int th infrared device directly t0 the h0st system t0 achive a desirable result.

• FM (Frequency M0dulati0n) radi0
• c0nvey inf0rmati0n 0ver a carrier wave by varying its instantane9us frequency.
• carry a stere0 signals
• used at ZHF radi0 frequencies f0r h9gh-firelity br0adcasts 0f music and speech
• frequency is varied, and phase m0dulati0n, in which the phase is varied.

• AM (Amplittude M0dulati0n)

• technique used in electr0nic c0mmunicati0n, m0st c0mm0nly f0r transmitting inf0rmati0n v0a radi0 carrier wave.
• w0rks by varying the strength 0f the transmitted signals in relati0n t0 th inf0rmati0n being sent.
• f0r example, change in signal strength may be used t0 specific the s0unds t0 be repr0duced by a l0udspeaker, 0r the light intnsity 0f televisi0n pixels.