Kɔmputa So Nkitahodie
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Ɛfiri Wikipidia, Nimdeɛbuukuu kwa
"Datacom" no so kɔ ha. Sɛ wopɛ dwumadie foforɔ a, hwɛ Datacom (disambiguation).Wopɛ nsɛmfua foforo a, hwɛ Network.
Kɔmputa ntam nkitahodi yɛ kɔmputa ahodoɔ a wɔkyɛ nnoɔma a ɛwɔ ntwamutam node ahodoɔ so anaasɛ wɔde ma. Kɔmputa ahorow de nkitahodie nhyehyɛe ahorow a wɔtaa de di dwuma wɔ dijitaal nkitahodi ahodoɔ so di dwuma de ne wɔn ho wɔn ho di nkitaho. Saa nkitahodi yi yɛ telecommunication network mfiridwuma a egyina honam fam nhama, optical, ne wireless radio-frequency akwan a ebia wɔahyehyɛ wɔ network topology ahorow mu.
Kɔmputa ntam nkitahodi node ahorow betumi ayɛ ankorankoro kɔmputa, server ahorow, nkitahodi nhyehyɛe ho hardware, anaa host afoforo a ɛyɛ soronko anaasɛ wɔde di dwuma wɔ ɔkwan a ɛkɔ akyiri so. Wɔde network address na ɛkyerɛ wɔn na ebia wɔwɔ hostnames. Hostnames yɛ adwuma sɛ labels a wɔbɛkae ma nodes no na wɔntaa nsakra wɔ mfitiase dwumadie akyi. Network address ahorow no di dwuma de hwehwɛ na wɔkyerɛ node ahorow no denam nkitahodi nhyehyɛe te sɛ Intanɛt Protocol so.
Wobetumi de gyinapɛn ahorow pii akyekyɛ kɔmputa ntam nkitahodi mu, a nea ɛka ho ne nkrasɛm a wɔde fa nsɛnkyerɛnne, bandwidth, nkitahodi nhyehyɛe a wɔde hyehyɛ ntwamutam akwantu, ntwamutam kɛse, topology, akwan a wɔfa so hwɛ kar akwan, ne ahyehyɛde no adwene. [ɛho hia sɛ wɔtwe adwene si so].
Kɔmputa ntam nkitahodi boa dwumadie ne dwumadie bebree, te sɛ Wiase Nyinaa Wɛbsaet a wobɛtumi akɔ, digyital video ne ɔdio, application ne storage servers a wɔkyɛ, printa ne fax mfiri, ne email ne instant messaging applications a wɔde di dwuma.
Ne Dwumadie
[sesa]Kɔmputa nkitahodi trɛw nnipa ntam nkitahodi mu denam ɛlɛtrɔnik akwan so denam mfiridwuma ahorow te sɛ imel, nkrasɛm a wɔde mena ntɛm ara, intanɛt so nkɔmmɔbɔ, nne ne video telefon so frɛ, ne video nhyiam so. Netwɛk ma kwan ma wɔkyɛ ntwamutam ne kɔmputa so nneɛma. Wɔn a wɔde di dwuma no betumi anya na wɔde nneɛma a mfiri a ɛwɔ ntwamutam no so de ama adi dwuma, te sɛ krataa bi a wobetintim wɔ ntwamutam printa a wɔakyɛ so anaasɛ mfiri a wɔde sie a wɔkyɛ a wɔde bedi dwuma. Netwɛk ma kwan ma wɔkyɛ fael, data, ne nsɛm ahorow afoforo a ɛma wɔn a wɔama wɔn tumi sɛ wɔde di dwuma no tumi nya nsɛm a wɔde asie wɔ kɔmputa afoforo a ɛwɔ netɛw no so. Distributed computing de kɔmputa so nneɛma di dwuma wɔ network bi so de yɛ nnwuma.
Network packet a wɔde di dwuma
[sesa]![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Network_packet.jpg/220px-Network_packet.jpg)
Nnɛyi kɔmputa ntam nkitahodi dodow no ara de protocol ahorow a egyina packet-mode transmission so na edi dwuma. Network packet yɛ data a wɔahyehyɛ a network a wɔasesa packet no de kɔ
Packets yɛ data ahorow abien: control information ne user data (payload). Control information no ma data a network no hia na ɛde user data no ama, sɛ nhwɛso no, source ne destination network addresses, mfomso a wohu codes, ne sequencing nsɛm. Mpɛn pii no, wohu control ho nsɛm wɔ packet headers ne trailers, a payload data wɔ ntam.
Wɔ packets mu no, wobetumi akyɛ bandwidth a ɛwɔ transmission medium no mu yiye wɔ wɔn a wɔde di dwuma no mu sen sɛ wɔde circuit switched network no . Sɛ obiako ntumi nkɔma packets a, wobetumi de packets a efi nnipa afoforo hɔ ahyɛ link no ma, na enti wobetumi akyɛ ɛka no, a biribiara ntwitware mu, sɛ wɔamfa link no nni dwuma mmoroso a. Mpɛn pii no, ɔkwan a ɛsɛ sɛ packet fa so fa network so no nni hɔ ntɛm ara. Sɛ ɛba saa a, wɔde packet no to ntonto mu na ɛtwɛn kosi sɛ link bi bɛba free.
Honam fam nkitahodi mfiridwuma a ɛwɔ packet network ahorow mu no taa to packets no kɛse ano hye kɔ maximum transmission unit (MTU) pɔtee bi so. Wobetumi akyekyɛ nkrasɛm a ɛware no mu ansa na wɔde akɔ baabi foforo na sɛ packets no ba pɛ a, wɔsan boaboa ano de yɛ mfitiase nkrasɛm no.
Netwɛk topology a ɛwɔ hɔ
[sesa]![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/97/NetworkTopologies.svg/220px-NetworkTopologies.svg.png)
Mpɛn pii no, honam fam anaa asasesin mu mmeae a ntwamutam node ne nkitahodi ahorow no wɔ no nni nkɛntɛnso kɛse biara wɔ ntwamutam bi so, nanso ntwamutam bi nkitahodi ahorow a ɛwɔ ntam no betumi aka ne nkɔso ne ahotoso kɛse. Wɔ mfiridwuma pii te sɛ bɔs anaa nsoromma ntam nkitahodi mu no, sɛ obi adi nkogu pɛnkoro a, ebetumi ama ntam nkitahodi no adi huammɔ koraa. Mpɛn pii no, dodow a nkitahodi pii wɔ hɔ no, dodow no ara na nkitahodi nhyehyɛe no mu yɛ den; nanso dodow no ara na ne bo yɛ den sɛ wode bɛhyɛ mu. Enti, wɔhyehyɛ ntwamutam mfonini dodow no ara denam wɔn ntwamutam topology a ɛyɛ map a ɛkyerɛ nkitahodi a ntease wom a ɛwɔ ntwamutam host ahorow mu.
Topology ahorow a wɔtaa de di dwuma ne:
- Bus network : nodes nyinaa wɔ abusuabɔ wɔ common medium bi so wɔ saa medium yi so. Eyi ne nhyehyɛe a wɔde dii dwuma wɔ Ethernet a edi kan no mu a wɔfrɛ no 10BASE5 ne 10BASE2 . Eyi da so ara yɛ topology a ɛtaa ba wɔ data link layer, ɛwom sɛ nnɛyi honam fam layer variants de point-to-point links di dwuma mmom, na ɛyɛ nsoromma anaa dua.
- Star network : node nyinaa na ɛka mfinimfini node soronko bi ho. Eyi ne nhyehyɛe a wɔtaa hu wɔ Ethernet LAN ketewa a wɔasesa mu, baabi a akraman biara di nkitaho kɔ mfinimfini ntwamutam switch mu, ne ntease mu wɔ wireless LAN mu, baabi a wireless akraman biara ne mfinimfini wireless access point no bɔ.
- Ring network : node biara abɔ ne benkum ne nifa fipamfo node, sɛnea ɛbɛyɛ a node nyinaa abɔ mu na node biara betumi adu ne yɔnko node ho denam node a ɛbɛfa benkum anaa nifa so. Token ring networks, ne Fiber Distributed Data Interface (FDDI), de topology a ɛte saa dii dwuma.
- Mesh network : wɔde node biara bata afipamfo dodow bi a wɔpɛ ho wɔ ɔkwan bi so a anyɛ yiye koraa no, traversal biako fi node biara so kɔ foforo biara so.
- Fully connected network : node biara abɔ node foforo biara a ɛwɔ network no mu.
- Nnua ntam nkitahodi : wɔahyehyɛ nodes no sɛnea wɔahyehyɛ no nnidiso nnidiso. Eyi ne abɔde mu topology ma Ethernet ntwamutam kɛse a ɛwɔ switch ahorow pii na enni redundant meshing.
Ntwamutam a wɔde kata so
[sesa]![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Network_Overlay_merged.svg/220px-Network_Overlay_merged.svg.png)
Overlay network yɛ virtual network a wɔasi wɔ network foforo so. Nodes a ɛwɔ overlay network no mu no, wɔde virtual anaa logical links na ɛka bom. Nkitahodi biara ne ɔkwan bi hyia, ebia ɛnam honam fam nkitahodi pii so, wɔ ntam nkitahodi a ɛwɔ ase no mu. Topology a ɛwɔ overlay network no mu no betumi ayɛ soronko (na ɛtaa yɛ saa) wɔ nea ɛwɔ ase no ho. Sɛ nhwɛso no, atipɛnfo ntam nkitahodi pii yɛ ntam nkitahodi a wɔde kata so. Wɔahyehyɛ wɔn sɛ nodes a ɛwɔ virtual system a ɛyɛ link ahorow a ɛkɔ Intanɛt atifi .[1]
Overlay networks wɔ hɔ fi bere a wɔyɛɛ networking bere a wɔde kɔmputa nhyehyɛe ahorow fa telefon nhama so de modem dii dwuma ansa na data network biara reba no.
Nhwɛso a ɛyɛ nwonwa sen biara a ɛfa overlay network ho ne Intanɛt ankasa. Mfiase no wɔyɛɛ Intanɛt ankasa sɛ ade a wɔde kata telefon ntam nkitahodi so .[1] Ɛnnɛ mpo, ɛkame ayɛ sɛ Intanɛt node biara tumi ne afoforo biara di nkitaho denam sub-networks a ɛwɔ topology ne mfiridwuma ahorow a ɛsono emu biara koraa so. Address resolution ne routing ne akwan a ɛma kwan ma wɔde IP overlay network a ɛka bom koraa no yɛ map kɔ ne network a ɛwɔ aseɛ no so.
Nhwɛsoɔ foforɔ a ɛfa overlay network ho ne distributed hash table, a ɛkyerɛ keys kɔ nodes a ɛwɔ network no mu. Wɔ saa tebea yi mu no, ntwamutam a ɛwɔ ase no yɛ IP ntwamutam, na ntwamutam a ɛkata so no yɛ pon (nokwarem no, asase mfonini ) a wɔde safe ahyɛ mu.
Wɔahyɛ nyansa nso sɛ overlay networks nyɛ ɔkwan a wɔbɛfa so ama Intanɛt so akwantuo atu mpɔn, te sɛ ɛnam ɔsom pa ho bɔhyɛ so nya streaming media a ɛkorɔn . Nsusuwii ahorow a atwam te sɛ IntServ, DiffServ, ne IP multicast nnyaa agye atom kɛse esiane sɛ ɛhwehwɛ sɛ wɔyɛ nsakrae wɔ router ahorow a ɛwɔ ntwamutam no mu nyinaa mu nti. </link> Ɔkwan foforo so no, wobetumi de overlay network adi dwuma nkakrankakra wɔ end-hosts a wɔde overlay protocol software no di dwuma no so, a wɔn a wɔde Intanɛt dwumadie ma no nyɛ biako . Overlay network no nni tumi biara wɔ sɛnea wɔde packets kɔ wɔ network a ɛwɔ aseɛ no mu wɔ overlay nodes mmienu ntam, nanso ɛtumi di, sɛ nhwɛsoɔ no, overlay nodes a ɛtoatoa soɔ a nkra bi fa mu ansa na adu baabi a ɛrekɔ no so </link> .
Sɛ nhwɛso no, Akamai Technologies hwɛ overlay network a ɛma wotumi de ho to so, etu mpɔn a wɔde ma ( multicast bi ). Adesua mu nhwehwɛmu bi ne end system multicast,[2] resilient routing ne quality of service adesua, ne afoforo.
Netwɛk nkitahodi ahorow
[sesa]Nneɛma a wɔde mena (a wɔtaa frɛ no wɔ nhoma ahorow mu sɛ honam fam ade ) a wɔde di dwuma de ka mfiri ahorow bom ma ɛyɛ kɔmputa ntam nkitahodi no bi ne anyinam ahoɔden nhama, optical fiber, ne baabi a ɛnyɛ hwee. Wɔ OSI model mu no, wɔakyerɛkyerɛ softwea a wɔde bedi nsɛm ho amanneɛbɔ ho dwuma no mu wɔ layers 1 ne 2 — honam fam layer ne data link layer.
Abusua a wɔagye atom kɛse a wɔde kɔbere ne nhama nsɛm ho amanneɛbɔ di dwuma wɔ mpɔtam hɔ ntam nkitahodi (LAN) mfiridwuma mu no, wɔbom frɛ wɔn Ethernet. Media ne protocol gyinapɛn a ɛma nkitahodi tumi di nkitaho wɔ networked devices ntam wɔ Ethernet so no, IEEE 802.3 na ɛkyerɛkyerɛ mu. Wireless LAN gyinapɛn ahorow de radio asorɔkye di dwuma, afoforo de infrared nsɛnkyerɛnne di dwuma sɛ ade a wɔde mena. Power line nkitahodi de ɔdan bi mu anyinam ahoɔden nhama di dwuma de mena data.
Wɔde nhama ayɛ
[sesa]![Bundle of glass threads with light emitting from the ends](http://upload.wikimedia.org/wikipedia/commons/thumb/4/49/Fibreoptic.jpg/220px-Fibreoptic.jpg)
Wɔde mfiri a wɔde nhama ayɛ akuw a edidi so yi di dwuma wɔ kɔmputa so nkitahodi mu.
- Wɔde coaxial cable di dwuma kɛse ma cable television nhyehyɛe, adwumayɛbea adan, ne adwumayɛbea afoforo ma mpɔtam hɔ nkitahodi nhyehyɛe ahorow. Ahoɔhare a wɔde mena no fi bits ɔpepem 200 wɔ sekan biara mu kosi bɛboro bits ɔpepem 500 wɔ sekan biara mu. </link>
- ITU-T G.hn mfiridwuma de ofie nhama a ɛwɔ hɔ dedaw ( coaxial cable, telefon nhama ne anyinam ahoɔden nhama ) di dwuma de yɛ mpɔtam hɔ nkitahodi a ɛkɔ ntɛmntɛm.
- Wɔde Twisted pair cabling di dwuma ma wired Ethernet ne gyinapɛn afoforo. Ɛtaa yɛ kɔbere nhama 4 abien a wobetumi de adi dwuma ama nne ne data nyinaa. Nhama abien a wɔakyinkyim no boa ma crosstalk ne electromagnetic induction so tew . Ahoɔhare a wɔde mena no fi 2 Mbit/s kosi 10 Gbit/s. Twisted pair cabling wɔ akwan abien so: unshielded twisted pair (UTP) ne shielded twisted-pair (STP). Krataa biara wɔ category ratings pii mu, a wɔayɛ sɛ wɔmfa nni dwuma wɔ tebea ahorow mu.
![World map with red and blue lines](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/World_map_of_submarine_cables.png/220px-World_map_of_submarine_cables.png)
Optical fiber yɛ ahwehwɛ nhama. Ɛde hann a ɛbɔ a egyina hɔ ma data denam laser ne optical amplifiers so kɔ . Mfaso bi a ɛwɔ optical fibers so sen dade nhama ne sɛ ɛhwere nkrasɛm a ɛba fam koraa na ɛmma anyinam ahoɔden nhaw no. Sɛ wɔde dense wave division multiplexing di dwuma a, optical fibers tumi de data pii kɔ hann asorɔkye tenten ahorow so bere koro mu, na ɛma sɛnea wobetumi de data akɔ bit ɔpepepem pii wɔ sekan biara mu no kɔ soro kɛse. Wobetumi de optic fibers adi dwuma ama nhama a ɛkɔ akyiri a ɛde data rates a ɛkorɔn yiye, na wɔde yɛ po ase nkitahodi nhama de ka nsasepɔn ahorow bom. Fiber optics ahorow abien titiriw na ɛwɔ hɔ, single-mode optical fiber (SMF) ne multi-mode optical fiber (MMF). Single-mode fiber wɔ mfaso a ɛne sɛ etumi kura sɛnkyerɛnne a ɛne ne ho hyia mu kilomita du du anaa ɔha mpo. Multimode fiber bo yɛ mmerɛw sɛ wobewie nanso ɛyɛ mita ɔhaha kakraa bi anaa mpo du du kakraa bi pɛ, a egyina data rate ne cable grade so.[3]
Wireless a wɔde di dwuma
[sesa]![Black laptop with the router in the background](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Wireless_network.jpg/220px-Wireless_network.jpg)
Wobetumi de radio anaa anyinam ahoɔden akwan foforo a wɔfa so di nkitaho no ayɛ network nkitahodi ahorow a wɔmfa nhama nkɔ so.
- Asase so microwave a wɔde yɛ nneɛma – Asase so microwave nkitahodi de Asase so transmitters ne receivers a ɛte sɛ satellite dishes di dwuma. Asase so microwave ahorow wɔ gigahertz a ɛba fam mu, na ɛma nkitahodi nyinaa yɛ nea ɛkɔ baabi a wotumi hu ade. Relay gyinabea ahorow no ntam kwan bɛyɛ 40 miles (64 km) ntam kwan ware.
- Nkitahodi satellite ahorow – Satellite nso nam microwave so di nkitaho. Satellite ahorow no gyina ahunmu, na mpɛn pii no ɛwɔ geosynchronous orbit 35,400 km (22,000 mi) mu wɔ equator no atifi. Saa nhyehyɛe ahorow a ɛtwa Asase ho hyia yi tumi gye nne, data, ne TV so nsɛnkyerɛnne na ɛde kɔ.
- Cellular network ahorow de radio so nkitahodi mfiridwuma ahorow pii di dwuma. Nhyehyɛe ahorow no kyekyɛ ɔmantam a wɔakata so no mu ma ɛyɛ asasesin ahorow pii. Wɔde afiri a wɔde fa nsɛm a ahoɔden kakraa bi na ɛyɛ adwuma .
- Radio ne spread spectrum mfiridwuma – Wireless LAN ahorow de radio mfiridwuma a ɛwɔ frequency a ɛkorɔn a ɛte sɛ dijitaal cellular di dwuma. Wireless LAN ahorow de spread spectrum mfiridwuma di dwuma de ma nkitahodi tumi di mfiri ahorow pii ntam wɔ beae kakraa bi. IEEE 802.11 kyerɛkyerɛ radio-asorɔkye mfiridwuma a wɔabue ano a wɔfrɛ no Wi-Fi a ɛyɛ dɛ a ɛtaa ba mu.
- Free-space optical communication de hann a wotumi hu anaa a wontumi nhu di dwuma ma nkitahodi. Mpɛn pii no, wɔde line-of-sight propagation di dwuma, na ɛma mfiri a wɔde di nkitaho no si baabi a ɛwɔ honam fam no ano hye.
- Intanɛt a ɛtrɛw kɔ okyinnsoromma ahorow ntam nsusuwii ahorow so denam radio asorɔkye ne akwan a wɔfa so hwɛ ade so, Interplanetary Internet .[4]
- IP over Avian Carriers yɛ April ɔkwasea a ɛyɛ serew Request for Comments, a wɔde mae sɛ . Wɔde dii dwuma wɔ asetra ankasa mu wɔ afe 2001.[2]
Netwɛk node ahorow
[sesa]Sɛ honam fam nkrasɛm biara da nkyɛn a, wɔde nhyehyɛe no adansi nneɛma atitiriw afoforo te sɛ ntwamutam ntam nkitahodi controllers, repeaters, hubs, bridges, switches, routers, modems, ne firewalls na ɛkyekye ntwamutam ahorow. Mpɛn pii no, adwinnade pɔtee biara bɛkura adansi nneɛma pii na enti ebetumi ayɛ nnwuma pii.
Netwɛk nkitahodi ahorow
[sesa]![A network interface circuit with a port for ATM](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/ForeRunnerLE_25_ATM_Network_Interface_%281%29.jpg/220px-ForeRunnerLE_25_ATM_Network_Interface_%281%29.jpg)
Network interface controller (NIC) yɛ kɔmputa hardware a ɛde kɔmputa no bata network media ho na ɛwɔ tumi a ɛde di network ho nsɛm a ɛba fam ho dwuma. Sɛ nhwɛso no, NIC no betumi anya nkitahodi bi a wɔde gye nhama, anaasɛ wim a wɔde fa wireless transmission ne gye, ne circuitry a ɛbata ho.
Wɔ Ethernet ntwamutam mu no, NIC biara wɔ Media Access Control (MAC) address soronko —a wɔtaa de sie wɔ controller no daa memory mu. Sɛnea ɛbɛyɛ a wɔbɛkwati address ntawntawdi wɔ network mfiri ahorow ntam no, Institute of Electrical and Electronics Engineers (IEEE) hwɛ MAC address soronko so na ɛhwɛ so. Ethernet MAC address kɛse yɛ octets asia . Wɔde octets abiɛsa a ɛho hia sen biara no asie sɛ wɔde bɛkyerɛ wɔn a wɔyɛ NIC. Saa adwinnan yi, a wɔde wɔn prefixes a wɔde ama wɔn nkutoo na edi dwuma, de Ethernet interface biara a wɔyɛ no octets abiɛsa a ɛho nhia pii no ma wɔ ɔkwan soronko so.
Repeaters ne hubs a wɔde yɛ nneɛma
[sesa]Repeater yɛ ɛlɛtrɔnik mfiri a egye network signal, ɛho tew fi dede a ɛho nhia ho na ɛsan yɛ no foforo. Wɔsan de sɛnkyerɛnne no kɔ tumi a ɛkorɔn mu, anaasɛ ɛkɔ akwanside no fa foforo sɛnea ɛbɛyɛ a sɛnkyerɛnne no betumi atwa akwan tenten a ɛrensɛe. Wɔ twisted-pair Ethernet nhyehyeɛ dodoɔ no ara mu no, wɔhia repeaters ma cable a ɛkyɛ boro mita 100. Sɛ wɔde fiber optics di dwuma a, repeaters betumi ayɛ kilomita du anaa ɔhaha pii mpo.
Repeaters yɛ adwuma wɔ physical layer a ɛwɔ OSI model no so nanso ɛda so ara hia bere kakra na wɔasan ayɛ signal no. Eyi betumi ama propagation delay a ɛka network adwumayɛ na ebetumi aka adwumayɛ a ɛfata. Nea ɛde ba ne sɛ, ntwamutam nhyehyɛe pii to repeater dodow a wɔde di dwuma wɔ ntwamutam mu ano hye, s.e., Ethernet 5-4-3 mmara .
Ethernet repeater a ɛwɔ port ahorow pii no yɛ nea wonim no sɛ Ethernet hub . Wɔ reconditioning ne distributing network signals akyi no, repeater hub boa ma wohu collision detection ne fault isolation ma network no. Hub ne repeater a ɛwɔ LAN mu no ayɛ nea ne bere atwam kɛse esiane nnɛyi network switch ahorow nti.
Bridges ne switch ahorow
[sesa]Network bridges ne network switches yɛ soronko wɔ hub ho efisɛ ɛde frames kɔ ports a ɛka nkitahodi no ho nkutoo bere a hub de kɔ ports nyinaa so.[2] Bridges wɔ port abien pɛ nanso wobetumi asusuw switch ho sɛ multi-port bridge. Switches taa wɔ ports pii, a ɛma nsoromma topology yɛ mmerɛw ma mfiri ahorow, ne cascading switch afoforo.
Bridges ne switches yɛ adwuma wɔ data link layer (layer 2) a ɛwɔ OSI model no mu na ɛbɔ traffic wɔ network afa mmienu anaa nea ɛboro saa ntam de yɛ local network baako. Wɔn baanu nyinaa yɛ mfiri a ɛde data frame ahorow kɔ port ahorow ntam a egyina destination MAC address a ɛwɔ frame biara mu so.[2] Wosua abusuabɔ a ɛda honam fam hyɛn gyinabea ahorow ne MAC address ahorow ntam denam frame ahorow a wɔagye no fibea address ahorow a wɔhwehwɛ mu na wɔde frame no kɔ bere a ɛho hia nkutoo. Sɛ wɔde wɔn ani asi MAC a wonnim a wɔrekɔ so a, afiri no bɔ abisade no kɔ hyɛn gyinabea nyinaa gye fibea no, na ehu beae no fi mmuae no mu.
Bridges ne switches kyekyɛ network no collision domain no mu nanso ɛkura broadcast domain baako mu. Network nkyekyɛmu a ɛnam bridge ne switching so boa ma wɔpaapae network kɛseɛ a ɛyɛ congested mu ma ɛyɛ ntwamu nketewa a ɛyɛ adwuma yie a wɔaboaboa ano.
Router ahorow a wɔde di dwuma
[sesa]![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Adsl_connections.jpg/220px-Adsl_connections.jpg)
Router yɛ internetworking device a ɛde packets kɔ networks ntam denam addressing anaa routing nsɛm a ɛka packet no mu a ɛdi ho dwuma no so. Wɔtaa di routing ho nsɛm no ho dwuma de ka routing table no ho . Router de ne routing table di dwuma de kyerɛ baabi a wɔde packets bɛkɔ na enhia broadcasting packets a ɛnyɛ adwuma yiye mma network akɛse paa.
Modem ahorow
[sesa]Wɔde modem (modulator-demodulator) di dwuma de fa waya a wɔannwene no mfiase no amma dijitaal ntwamutam akwantu, anaasɛ wireless so na ɛka ntwamutam node ahorow bom. Sɛnea ɛbɛyɛ na wɔayɛ eyi no, dijitaal sɛnkyerɛnne no sesa carrier signals biako anaa nea ɛboro saa ma ɛyɛ analog signal a wobetumi ayɛ no sɛnea ɛbɛyɛ a ɛbɛma wɔanya su ahorow a ɛho hia ma transmission. Modem ahorow a edi kan no sesaa ɔdio nsɛnkyerɛnne a wɔde fa nne telefon nhama a wɔahyɛ da ayɛ so. Wɔda so ara taa de modem di dwuma ma telefon nhama, wɔde dijitaal akrafo nhama mfiridwuma ne cable television nhyehyɛe a wɔde DOCSIS mfiridwuma di dwuma.
Firewalls a wɔde yɛ nneɛma
[sesa]Firewall yɛ ntwamutam mfiri anaa softwea a wɔde hwɛ ntwamutam ahobanbɔ ne akwan a wɔfa so kɔ hɔ ho mmara so. Wɔde ogya fasuo hyɛ nkitahodi a ɛda emu ntwamutam a ahobanbɔ wom ne abɔnten ntwamutam a ebetumi ayɛ nea ahobammɔ nnim te sɛ Intanɛt ntam. Wɔtaa hyehyɛ Firewalls sɛ ɛbɛpow kwan a wɔfa so kɔ hɔ a wɔhwehwɛ fi mmeae a wonnim bere a wɔma nneyɛe a efi mmeae a wonim no kwan. Dwuma titiriw a ogya fasu di wɔ nkitahodi nhyehyɛe mu ahobammɔ mu no nyin ne kɔmputa so ntua a ɛkɔ soro bere nyinaa no .
Nkitahodi ho nhyehyɛe ahorow
[sesa]Nkitahodi nhyehyɛe yɛ mmara ahorow a wɔde sesa nsɛm wɔ ntwamutam so. Nkitahodi nhyehyɛe ahorow wɔ su ahorow. Ebia wɔyɛ nkitahodi-oriented anaasɛ connectionless, wobetumi de circuit mode anaa packet switching adi dwuma, na wobetumi de hierarchical addressing anaa flat addressing adi dwuma.
![When a router is present, message flows go down through protocol layers, across to the router, up the stack inside the router, and back down again and is sent on to the final destination where it climbs back up the stack](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Message_flows_and_Routing.svg/250px-Message_flows_and_Routing.svg.png)
Wɔ protocol stack, a wɔtaa yɛ no sɛnea OSI nhwɛso no te no, wɔkyekyɛ nkitahodi dwumadi ahorow mu yɛ no protocol layers, baabi a layer biara de layer a ɛwɔ n’ase no nnwuma di dwuma kosi sɛ layer a ɛba fam koraa no bedi hardware a ɛde nsɛm kɔ media no so no so. Protocol layering a wɔde di dwuma no wɔ baabiara wɔ kɔmputa so nkitahodi mu. Nhwɛsoɔ a ɛho hia a ɛfa protocol stack ho ne HTTP (Wiase Wide Web protocol) a ɛnam TCP so wɔ IP (Internet protocols) so wɔ IEEE 802.11 (Wi-Fi protocol) so. Wɔde saa stack yi di dwuma wɔ wireless router ne ofie dwumadiefoɔ no ankasa kɔmputa ntam berɛ a ɔdefoɔ no rehwehwɛ wɛbsaet no so.
Nkitahodi nhyehyɛe pii wɔ hɔ, na wɔaka emu kakraa bi ho asɛm wɔ ase ha
Protocol ahorow a wɔtaa de di dwuma
[sesa]Intanɛt so protocol suite
[sesa]Intanɛt protocol suite, a wɔsan frɛ no TCP/IP, ne nnɛyi nkitahodi nyinaa fapem. Ɛde nnwuma a nkitahodi nnim na ɛfa nkitahodi ho ma wɔ ntwamutam a wontumi mfa ho nto so a efi awosu mu a datagram a wɔde Intanɛt protocol (IP) di dwuma de fa so. Wɔ ne titiriw mu no, protocol suite no kyerɛkyerɛ addressing, identification, ne routing specifications ma Internet Protocol Version 4 (IPv4) ne IPv6, protocol no awo ntoatoaso a edi hɔ a ɛwɔ addressing tumi a ɛtrɛw kɛse. Intanɛt protocol suite no ne protocol ahorow a ɛkyerɛkyerɛ Intanɛt so.[5]
IEEE 802 na ɛwɔ hɔ
[sesa]IEEE 802 yɛ IEEE gyinapɛn abusua a ɛfa mpɔtam hɔ nkitahodi ne nkurow akɛse mu nkitahodi ho. IEEE 802 protocol suite a edi mũ no ma nkitahodi tumi ahorow ahorow. Protocol ahorow no wɔ addressing nhyehyɛe a ɛyɛ tratraa. Wɔyɛ adwuma kɛse wɔ layers 1 ne 2 a ɛwɔ OSI model no mu.
Sɛ nhwɛso no, MAC bridging ( IEEE 802.1D ) di Ethernet packets a wɔde Spanning Tree Protocol di dwuma no kwan ho dwuma. IEEE 802.1Q kyerɛkyerɛ VLANs mu, na IEEE 802.1X kyerɛkyerɛ port-based Network Access Control protocol mu, a ɛyɛ nnyinaso ma nokwaredi akwan a wɔde di dwuma wɔ VLANs mu [6] (nanso wohu wɔ WLANs mu nso [7] ) . – ɛyɛ nea ofie dwumadiefoɔ no hu berɛ a ɛsɛ sɛ ɔdefoɔ no hyɛ "wireless access key" mu.
Ethernet a wɔde di dwuma
[sesa]Ethernet yɛ mfiridwuma abusua bi a wɔde di dwuma wɔ wired LAN ahorow mu. Wɔde gyinapɛn ahorow bi a wɔaka abom a wɔfrɛ no IEEE 802.3 a Institute of Electrical and Electronics Engineers tintimii na ɛkyerɛkyerɛ mu.
Wireless LAN a wɔde di dwuma
[sesa]Wireless LAN a egyina IEEE 802.11 gyinapɛn so, a wɔsan frɛ no kɛse sɛ WLAN anaa WiFi no, ebia ɛyɛ IEEE 802 protocol abusua no muni a wonim no yiye ma wɔn a wɔde di dwuma wɔ fie nnɛ. IEEE 802.11 kyɛ agyapadeɛ pii ne Wired Ethernet.
SONET/SDH na ɛyɛ adwuma
[sesa]Synchronous optical networking (SONET) ne Synchronous Digital Hierarchy (SDH) yɛ standardized multiplexing protocols a ɛde dijitaal bit nsuten pii fa optical fiber so de laser di dwuma. Mfiase no wɔyɛɛ no sɛnea ɛbɛyɛ a wɔde amansin kwan so nkitahodi ahorow fi mmeae ahorow bɛkɔ, titiriw sɛnea ɛbɛyɛ a wɔbɛboa dijitaal telefon a wɔde amansin-sesa . Nanso, ɛnam ne protocol neutrality ne transport-oriented features nti, SONET/SDH nso na ɛda adi pefee sɛ wɔpaw sɛ wɔde Asynchronous Transfer Mode (ATM) frames bɛkɔ.
Asynchronous Nneɛma a Wɔde Kɔma Nneɛma
[sesa]Asynchronous Transfer Mode (ATM) yɛ ɔkwan a wɔfa so sesa telefon so nkitahodi nhyehyɛe. Ɛde asynchronous time-division multiplexing di dwuma na ɛde data kɔ nkwammoaa nketewa a ne kɛse yɛ pɛpɛɛpɛ mu . Eyi yɛ soronko wɔ protocol afoforo te sɛ Intanɛt protocol suite anaa Ethernet a ɛde packets anaa frame ahorow a ne kɛse sesa di dwuma no ho . ATM wɔ nsɛsoɔ wɔ circuit ne packet switched networking nyinaa mu. Wei ma ɛyɛ paw pa ma ntwamutam a ɛsɛ sɛ ɛdi atetesɛm mu data akwantuo a ɛkɔ soro, ne berɛ ankasa, nsɛm a ɛnyɛ den te sɛ nne ne video nyinaa ho dwuma. ATM de nkitahodi-oriented model a ɛsɛ sɛ wɔde virtual circuit si hɔ wɔ endpoints abien ntam ansa na data exchange ankasa afi ase.
ATM da so ara di dwuma wɔ akwansin a etwa to, a ɛyɛ nkitahodi a ɛda Intanɛt dwumadibea bi ne nea ɔde di dwuma wɔ fie ntam no mu.[2]
Asasesin mu nsenia
[sesa]Nanoscale ntam nkitahodi wɔ nneɛma atitiriw a wɔde di dwuma wɔ nanoscale no mu, a nkrasɛm a wɔde fa nneɛma ka ho, na ɛde honam fam nnyinasosɛm ahorow a ɛsono wɔ macroscale nkitahodi akwan horow ho di dwuma. Nanoscale nkitahodi trɛw nkitahodi mu kɔ sensor ne actuators nketewa paa te sɛ nea wohu wɔ abɔde a nkwa wom nhyehyɛe mu na ɛsan nso taa yɛ adwuma wɔ mmeae a ɛbɛyɛ katee dodo ma nkitahodi akwan afoforo.[8]
Ankorankoro mpɔtam hɔ nkitahodie
[sesa]Personal area network (PAN) yɛ kɔmputa ntam nkitahodi a wɔde di nkitaho wɔ kɔmputa ne nsɛm ho mfiridwuma mfiri ahorow a ɛbɛn onipa biako ntam. Mfiri a wɔde di dwuma wɔ PAN mu no nhwɛso bi ne ankorankoro kɔmputa, printa, fax mfiri, telefon, PDA, scanner, ne video game console. Ebia PAN bi bɛka mfiri a wɔde nhama ne nea wɔde nhama ayɛ ho. Mpɛn pii no, baabi a PAN betumi adu no trɛw kɔ mita 10.[2] Wɔtaa de USB ne FireWire nkitahodi na ɛyɛ PAN a wɔde nhama ayɛ bere a mfiridwuma te sɛ Bluetooth ne infrared nkitahodi taa yɛ PAN a wɔde nhama ayɛ.
Baabi A Menyaa Mmoa Firii
[sesa]- ↑ 1.0 1.1 D. Andersen (October 2001), Resilient Overlay Networks, Association for Computing Machinery, archived from the original on 2011-11-24, retrieved 2011-11-12
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5
{{cite web}}
: Empty citation (help) - ↑ Meyers, Mike (2012). CompTIA Network+ exam guide : (Exam N10-005) (5th ed.). New York: McGraw-Hill. ISBN 9780071789226. OCLC 748332969.
- ↑ A. Hooke (September 2000), Interplanetary Internet (PDF), Third Annual International Symposium on Advanced Radio Technologies, archived from the original (PDF) on 2012-01-13, retrieved 2011-11-12
- ↑ Tanenbaum, Andrew S. (2003). Computer Networks (4th ed.). Prentice Hall.
- ↑ IEEE Standard for Local and Metropolitan Area Networks--Port-Based Network Access Control. IEEE STD 802.1X-2020 (Revision of IEEE STD 802.1X-2010 Incorporating IEEE STD 802.1Xbx-2014 and IEEE STD 802.1Xck-2018). February 2020. 7.1.3 Connectivity to unauthenticated systems. doi:10.1109/IEEESTD.2020.9018454. ISBN 978-1-5044-6440-6. Archived from the original on 2023-02-04. Retrieved 2022-05-09.
- ↑ IEEE Standard for Information Technology--Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks--Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. IEEE STD 802.11-2020 (Revision of IEEE STD 802.11-2016). February 2021. 4.2.5 Interaction with other IEEE 802 layers. doi:10.1109/IEEESTD.2021.9363693. ISBN 978-1-5044-7283-8. Archived from the original on 2022-05-17. Retrieved 2022-05-09.
- ↑ Bush, S. F. (2010). Nanoscale Communication Networks. Artech House. ISBN 978-1-60807-003-9.