Kimiyya da Fasahar Sadarwa!: Tsarin Sadarwa A Tsakanin Kwamfutoci (2)

Makon Jiya

A cikin kasidar da ta gabata makon jiya ne mai karatu ya samu bayanai kan tsarin sadarwa a tsakanin kwamfutoci, abinda a Turance ake kira Computer Networking. Bayan ‘yar gajeriyar gabatarwa, mun kawo bayani kan ma’ana da kuma nau’ukan tsarin sadarwan da ke tsakanin kwamfutoci, inda daga karshe muka nuna ma mai karatu cewa samun cikakkiyar fahimta kan irin tsarin da kwamfutoci ke sadar da bayanai a tsakaninsu ba abu bane mai sauki, musamman ma ganin cewa kashi sittin ko sama da haka na alakar da ke tsakanin ruhin kowace irin na’ura ta sadarwa da gangar-jikinta, ba alaka bace da za a iya gani a zahiri, sam. Don haka sai dai kawai a kwatanta ma mai karatu don ya samu kiyastaccen tsarin a kwakwalwansa. Amma duk da haka, wannan alaka na nan, kuma tabbatacciya ce. Wannan ma tasa muka kawo ka’idar “Black Box”, don yanke hanzari. Har wa yau, mun dan fara bayanai kan komatsen da ke taimakawa wajen wannan alaka a tsakanin kwamfutoci, inda muka ambaci kayayyaki da na’urori irinsu Fiber-Optic Cables, Coaxial Cables, Twisted Pair (dukkan nau’ukan ta), Wireless Frequency Radio (Wi-Fi), Routers, Switches, Satellite Dish/Mast, da dai sauran karikitai. Wadannan su ne galibin abubuwan da mai karatu zai iya gani da idonsa, a yayin da aka hada kwamfutoci suke sadarwa ko Magana da junansu, wanda kuma hakan wani dan yanki ne kawai cikin tsarin alakar. To a yau zamu ci gaba da bayani kan ka’idojin da ke taimaka ma kwamfuta hada alaka da ‘yar uwanta, bayan samuwan wadannan komatse da bayanansu suka gabata makon jiya.

Ka’idojin Sadarwa (Network Protocols)

Bayan komatsen sadarwa na zahiri da muke iya gani, sai kuma ginannun ka’idojin da kowace kwamfuta ta mallaka a halittarta da aka halitta ta a kai tun ran gini. Muna yawan ambaton kalmar ka’ida a galibin lokuta kan abinda ya shafi kwamfuta, dole ce ta kawo haka, domin ka’ida, kamar yadda muka nuna a kasidar Dunkulallun Ka’idojin Mu’amala a Intanet, ba a rayuwa sai da ita; rayuwar nan mai kyau ce ko mummuna. Don haka ka’ida na iya zama kyakkyawa ko mummuna, amma dai dole ne a same ta a dukkan mu’amalar rayuwa. To haka abin yake a tsarin mu’amala ko sadarwan da kwamfuta ke yi da ‘yar uwanta. Ka’idar Sadarwa ko Protocol, a ilimin kwamfuta, na nufin “tsarin da kowace kwamfuta ke amfani dashi wajen mikawa da karban kowane irin sako ne tsakaninta da wata kwamfuta ko na’urar sadarwa.” Yadda ka san mutane na da irin nasu hanyar da suke bi wajen sadarwa; ya zama suna jin yare daya; sun fahimci manufar juna; ba matsala wajen karban sakon. Duk da yake wasu lokuta akan samu wani baya jin yaren wani, amma akan iya sadarwa ta amfani da luggan bebaye ko kurame. Amma a kwamfuta haka baya yiwuwa. Dole ne kowace kwamfuta ta fahimci yaren da mai aiko mata sako ke yi, idan ba haka ba, babu sadarwa. Wannan tasa aka gina kwamfutoci akan yardaddun ka’idojin sadarwa a duniya. Wannan na nufin duk inda ka samu kwamfuta, to zaka samu tana jin yaren ‘yar uwanta, muddin lafiyarta kalau ne ba zazzabi mai tsanani take ba. Hukumar da ke lura da gina wadannan ka’idoji kuwa ita ce International Standard Organisation (ISO) da ke kasar Amurka. Hukuma ce da ta tattaro masana kan harkan kwamfuta da manhajanta, da kuma kungiyoyi ko kamfanonin sadarwa na duniya. Idan wani kamfani ya kirkiri wata Ka’ida da yake ganin zai taimaka wajen habbaka sadarwa a tsakanin kwamfutoci, sai ya mika ma wannan hukuma, ita kuma ta yi nazari. Da zaran an samu amincewa, sai ayi maza a sanar da kamfanoni masu kera kwamfutoci da karikitanta, da kuma masana ko magina babban manhajan kwamfuta (System Programmers), don su dauki wannan ka’ida don yin aiki da ita kan dukkan abinda zasu gina ko tsara mai alaka da kwamfuta, nan gaba. Su wadannan ka’idoji ginannun tsare-tsare ne da ake shigar da su cikin kwakwalwan kwamfuta, wanda muddin tana tunani, da zaran wani bukata wanda ya danganci wannan ka’ida ya iso gareta, nan da nan zata fahimta, ta kuma yi abinda ake son ta da yi ba tare da bata lokaci ba.

Matakan Sadarwa Tsakanin Kwamfutoci

Kamar yadda bayani ya gabata makon da ya wuce, kafin a samu sadarwa tsakanin kwamfuta, dole ne a samu kwamfutoci a kalla biyu; daya mai mikawa, dayan kuma mai karban bayanin. Ko kuma daya mai neman bayani, daya kuma mai bayarwa. Muka ce a kowane hali ake, wacce zata bayar da bayanai ita ake kira Remote Host, ko Server, ko Terminal ko kuma Workstation. Ita ce mai dauke da hanyoyin mika bayanai da taskance su. Dayar kuma, wacce ke neman a aiko mata, akan kira ta Client, a turancin Kwamfuta. Don haka, da zaran Remote Host ko Server ta aiko da sako zuwa wata kwamfutar, to akwai Matakai ko Zanguna guda bakwai da sakon zai bi. A duk zangon da ya zo, za a masa alama don a sheda shi a zangon da zai tarar a gaba, haka haka har ya isa zuwa kwamfutar da aka aika shi ba tare da samun matsala ba. Wannan tsari na lika ma bayanai ko sakonni alama, a hanyarsu ta zuwa inda aka aika su, shi ake kira Data Encapsulation a turancin Kwamfuta. Kwamfutar da ke aikawa da wannan sako, zata kacalcala sakon ne zuwa tsibi-tsibi, kowane tsibi (abinda masana kwamfuta suke kira Datagram, jam’insu shi ake kira Packet Switch) zata bashi alama, kamar yadda bayani ya gabata a sama. Sannan ta turo su ta wadannan zanguna guda bakwai, wadanda ake kira Layers a turance. Tsarin da ke kunshe da wadannan zanguna bakwai shine The Open Systems Interconnect Model, ko kace OSI a takaice. An kuma kirkiri wannan tsari ne cikin shekarar 1981. Amma kafin nan, tsarin TCP/IP Model ake amfani dashi, wanda ya kunshi zanguna hudu ne kacal, duk da yake akwai dukkan ka’idojin da ake bukata a ciki. To a wadannan matakai ne ake samun dukkan ka’idojin sadarwa tsakanin kwamfutoci, watau Networking Protocols ko kuma Standards. Ina ganin zai dace mu yi takaitaccen bayani kan dukkan matakan da galibin ka’idojin da kowanne ke kunshe dashi, don mai karatu ya fahimci yadda lamarin yake.

The Open Systems Interconnect Model (OSI)

Da zaran kana son aikawa da sako daga wata kwamfuta zuwa wata, zangon farko da sakon zai fara kasancewa ciki ko biyowa ta cikinsa, shine mataki na bakwai; Layer 7, watau Application Layer. Wannan shine matakin manhajan da kake son aikawa da sakon ta hanyarsa. A wannan mataki ne zaka shigar da sunan wanda kake son aika masa da sakon, ko sunan kwamfutar da kake son aika mata da sakon, da kuma matanin sakon. Application Layer ne ke da hakkin tabbatar da cewa sakonka ya samu wanda ka aika masa ta hanyar adireshin da ka shigar, domin wannan zango ne ke dauke da ka’idojin da ke wannan aiki. A wannan zango na Layer 7 akwai Ka’idoji irinsu: File Transfer Protocol (FTP) – ka’idar da ke taimakawa wajen sauko da jakunkunan bayanai daga wata kwamfutar zuwa ko daga wani gidan yanar sadarwa mai dauke da bayanai zuwa kan kwamfutar ka, ko kuwa dora bayanai a gidan yanar sadarwa. Wannan shine shahararren aikin ta, amma da bayyanar ka’idar Hypertext Transfer Protocol (HTTP), sai kasuwar FTP ta mace kurmus. Yanzu galibin aikin da ake yi da masarrafar FTP bai wuce dora jakunkunan bayanai zuwa gidajen yanar sadarwa ba, don masu lilo da tsallake-tsallake su rinka isa garesu. Duk bayanan da zaka ta cin karo dasu a gidajen yanar sadarwa, da ka’idar File Transfer Protocol ko FTP aka dora su cikin kwamfuta. Sai kuma ka’idar Trivial File Transfer Protocol (TFTP), wacce kanwar FTP ce. Daga cikin ka’idojin da ke wannan zango har wa yau akwai Domain Name Service (DNS), wacce ke taimakawa wajen nemo sunan kwamfutar da za a isar da sakon gareta, ta hanyar adireshin da ka bayar lokacin aikawa da sakon. Sai ka’idar Simple Mail Transfer Protocol (SMTP), wacce ke taimakawa wajen aikawa da sakonnin Imel daga kwamfutar da ka aika zuwa uwar garken da ke dauke da jakar wasikar wanda ka aika masa. Muhimman ka’idojin sadarwan da ke wannan zango kenan. Da zaran ka aika da sakon, sai Layer 6, watau Presentation Layer. Wannan zango ne zai juya sakonka daga haruffa ko bakaken da kayi amfani dasu zuwa yaren kwamfuta, wanda ba wanda zai iya fahimta, ko da kuwa wani ya tare sakon a hanya. Wannan aiki shi ake kira Encording. Daga nan kuma ya takura sakon (Compress) don kankanta shi. A wannan zango akwai ka’idoji irinsu Motion Picture Experts Group (MPEG), Joint Photographic Experts Group (JPEG), Tagged Image File Format (TIFF), wadanda ka’idoji ne na takura mizanin hotuna wajen aikawa dasu. Sai kuma ka’idar Hypertext Transfer Protocol (HTTP), wacce ke sadar da kwamfutar da kake kai da wacce ke dauke da gidan yanar sadarwan da kake son ziyarta, ta hanyar Rariyar Lilo (Browser). Sai kuma zango na gaba, Layer 5, ko Session Layer, wacce ke taimakawa wajen hada alaka tsakanin kwamfutar da ke aikawa da sakon da wacce zata karba. A wannan zango ne kwamfutarka ko wacce ke aikawa da sakon zuwa wata kwamfutar, zata san ko kwamfutar da ke karban sakon a shirye take ko a a. Wannan zangon ne ke tura sakon gaba, zuwa zangon gaba, bayan gama kintsa shi. Akwai ka’idar Structured Query Language (SQL), mai taimakawa wajen saukake neman bayanai daga rumbun kwamfutar da ke mikowa, ba tare da matsala ba. Daga nan sai Layer 5, watau Transport Layer, wanda ke gyatta sakon ka yadda suka zo kimtsi-kimtsi, wani na bin wani, don tabbatar da cewa wani bangare bai makale a zangon baya ba. Shahararriyar ka’idar da ke wannan zango ita ce ta Transmission Control Protocol (TCP), wacce ke sawwake mika sakonni, musamman ma shafukan yanar gizo, daga wata kwamfutar zuwa wata, cikin sauki. Sai kuma zangon gaba, Layer 3, watau Network Layer, zangon da ke lura da tsarin tsibin sakonnin da ke tafe, ya tabbatar babu wata mishikila cikin tsarin da aka masa a zangon baya, da kuma dora masa adireshin mai aikawa; mutum ne ko kwamfuta, don mai karban sakon ya san daga inda sakon ya fito. Nan ne ake da ka’idar Internet Protocol (IP), wanda zai damfara adireshin kwamfutar da ke aikowa da sakon. Adireshin kwamfuta shine lambobinta, wanda dashi ake iya sheda ta. Ana kiran sa IP Address, kuma da wadannan lambobi ne ake iya gane kowace kwamfuta a ko ina take. Ko da kuwa an juya wadannan lambobi ne zuwa adireshin gidan yanar sadarwa (misali a ce http://www.google.com), idan aka aiko sako daga wannan gidan yana, kafin ya fice, sai wannan zango na Network ya damfara lambobin kwamfutar a jikin sakon, don sanar da kwamfutar da ke karban sakon cewa “wance ce ta aiko wannan sako”, misali. Sai kuma Address Resolution Protocol (ARP), wacce aikinta ne ta tabbatar da cewa sakon ka ya isa zuwa adireshin da ka ayyana, ta hanyar tabbatar da lambobin kwamfutar da ke karban sakon, watau IP Address kenan. Sakon ka na wuce wannan zango sai Layer 2, watau Data Link Layer. Wannan shine zangon da zai karbi tsibe-tsiben sakon ka, tare da bayanan da ke like a jikinshi, ya kuma juya shi zuwa yanayin hasken lantarki, tunda ya wuce muhallin da zai ci gaba da zama a dabi’ar farko. Wannan yanayi na wutar lantarki kuwa shi ake kira Bits. Shahararren ka’idar da ke wannan zango kuwa ita ce Point-to-Point Protocol (PPP), wacce jaruma ce wajen mika sako daga wannan zango na kwamfutoci zuwa wannan ta hanyar wutar lantarki. To fa, sakon ka na wuce wannan zango sai zangon karshe, watau Layer 1, ko kace Physical Layer, wacce ke daukan wannan sako naka daga yanayin wuta ko hasken lantarki, ta bi dashi cikin wayoyin kebul da mai karatu ke gani a like a jikin kwamfuta, idan a tsarin gajeren zangon sadarwa ne, watau Local Area Network (LAN). Sai ya zarce zuwa na’urar Switch, wacce zata tura ma kwamfutar da aka aika mata. Idan kuma a tsarin faffadan zango ne, irin su Internet Connection ko kuma Wide Area Network (WAN), sai ta mika sakon ga na’urar Router, wanda zai dauke shi ta hanyar wayar iska a irin yanayin sakonnin rediyo, watau Radio Waves, don sadar dashi ga tauraron dan Adam (Satellite Dish ko Mast), ko kuma na’urar Wireless Frequency Radio (Wi-Fi). Da zaran ya iso nan, sai a mika ma wani na’uran Router da ke zangon da kwamfutar take, don ya cilla ma kwamfutar da aka aiko mata, ko ta bukata. Idan mai karban sakon na jiranka ne, nan take zai gani. Idan kuma bai ma sani ba, to duk lokacin da ya budo jakar Imel dinsa, ko ya budo kwamfutarsa, idan ba Imel bane, zai ga sakon, dauke da cikakkun bayananka, da lokacin da ka aiko da sauransu. To amma ta yaya hakan zai kasance, bayan an luguiguita sakon, an kacalcala shi zuwa wani yanayi a kwamfutar da ya fito?

Wannan abu ne mai sauki! Da zaran sakon ya bar kwamfutarka zuwa kwamfutar da aka aike shi, zai fara cin karo ne da zangon Physical Layer, wanda zai jujjaya shi, ya tabbatar garau sakon yake, sai ya cilla ma zangon Data Link Layer, yayi nashi. Sai zangon Network Layer, wanda zai tabbatar da ingancin lambar kwamfutar da ta aiko da sakon, in ba matsala, sai zangon Transport Layer. Da zaran ya wuce nan, sai zangon Session Layer, wanda zai lika ma sakon bayanan da zasu tabbatar da mazuwansa; watau adireshin mai aikowa, da na kwamfutar da ta aiko, da lokaci da sauransu. Sai zangon gaba, Presentation Layer, wanda idan mai karatu bai mance ba, munce a nan ne ake canza ma sako yanayi, tare da kacalcala shi tsibi-tsibi. To idan ya zo nan a wannan siffa, sai wannan zango ya mayar dashi zuwa cikakken sako, a irin yanayin da aka aiko shi. Idan hoto ne ko zane, zai mayar dashi zuwa yanayinsa na asali, in ma takura hoton yayi, zai bude shi ya bashi ‘yancinsa na asali. Ya shirya sakon dai tsaf, don mika ma zangon karshe, watau Application Layer. Wannan zango zai karbi sakon sai ya adana, idan mai karba ya budo, sai kawai ya samu sakon garau, kamar yadda aka aiko masa. To amma idan akwai matsala tsakanin lokacin da mai aikowa ta aiko kafin mai karba ta karba, da zaran sakon ya fara isa kwamfutar da zata karba, sai ayi masa birke mai kyau, a kuma mayar dashi zuwa inda ya fito. Babu kira, mai kuwa zai ci gawayi? A hanyarsa ta komawa ne, zangunan zasu lika masa bayanai na irin matsalar da ya samu a hanya. Allah Sarki Malam Muttaka, a koma gida, sai wani lokaci!

Kammalawa

Wannan a takaice shine abinda zamu iya kawowa. Ina kuma fatan mai karatu ya cizgi wani abu. Idan ma bai cizga ba, to duk kada ya damu. Komai da lokacinsa. A mako mai zuwa kuma zamu kawo bayani ne kan Manhajan Wasikar Hanyar Sadarwa (Imel), da dukkan ka’idojin da take tattare da su. In ma da hali, zamu kawo gajeren bayani kan shahararru daga cikin gidajen yanar sadarwa masu dauke da wannan manhaja, da irin siga ko tsarin da kowanne ke dashi. Ina mika sakon godiya da ban gajiya ga dukkan masu karatu. Allah Yai mana gam-da-katar cikin wannan wata mai alfarma, amin.