
session pora

computer networking yokka edu-porala osi namoonaalo, session pora pora 5.
session pora tudi-viniyogadaaru darakhaastu prakriyala madhya seshannu teravadaaniki, muusivaeyadaaniki mariyu nirvahinchadaaniki yantraamgaanni andistundi, antey.ii., pakshika shaashwata sambhaashana. communication sessionlalo applicationla madhya jarige abhyardhanalu mariyu pratispandanalu untaayi. session-layer sevalu saadhaaranamgaa remot proseasure calls (arpc) nuu upayoginche application vaataavaranaalaloo upayoginchabadataayi.
session-layer protocol yokka udaaharana osi protocol suut session-layer protocol, dheenini x.225 ledhaa ISO 8327 anie kooda pilustaaru. connection nashtam vishayamlo eee protocol connectionnu tirigi pondadaaniki prayatninchavacchu. oka connection ekkuva kaalam upayoginchakapothe, session-layer protocol daanini moosivesi tirigi teravavacchu. idhi puurti duplexes ledhaa haaph-duplexes operation kosam andistundi mariyu marpidi sandeshaala pravaahamlo samakaaleekarana paayintlanu andistundi.
session layer amaluku itara udaaharanalalo john information protocol (zip)-paeru binding prakriyanu samanvayam chese appletock protocol, mariyu session controll protocol (essipi)-dennet faze IV session-layer protocol unnaayi.
osi network nirmaanam yokka servies layer semantics lopala, session pora pradarsana pora nundi seva abhyardhanalaku pratispandistundi mariyu ravana poraku seva abhyardhanalanu jaarii chestundi.
sevalu.
anusandhaana sthaapana mariyu vidudala.
kaneesam, session pora rendu vaipula session anie piluvabade connectionnu erpaatu cheyadaaniki mariyu upayoginchadaaniki anumatistundi mariyu connectionnu kramabaddhamgaa vidudala cheyadaaniki anumatistundi.
osi namoonaalo, ravana pora oka anusandhanam kramabaddhamgaa vidudala cheyadaaniki baadhyata vahinchadu. badulugaa, session pora daaniki baadhyata vahistundi. ayithe, aadhunika tcp/aipi networklalo, tcp ippatike ravana pora vadda connectionlanu kramabaddhamgaa moosivestundi.
session connection vidudalaina tarvaata, antarleena ravana connectionnu maroka session connection kosam tirigi upayoginchavacchu. alaage, oka session connection aneka varusa ravana connectionlanu upayoginchavacchu. udaaharanaku, oka session samayamlo, antarleena ravana connection viphalamaithe, seshannu konasaaginchadaaniki session pora ravana connectionnu tirigi erpaatu cheyadaaniki prayatninchavacchu.
sambhaashana niyantrana.
session pora moodu ververu sambhaashana rakalanu andinchavacchu-rendu margalu ekakaalamlo (puurti-dwandwa), rendu margalu pratyaamnaayam (sagam-dwandwa), mariyu oka maargam (simplexes). idhi sambhaashana rakanni charchinchadaaniki yantraamgaalanu kooda andistundi, mariyu daetaanu pampadaaniki ledhaa konni niyantrana vidhulanu nirvahinchadaaniki yea vaipu "malupu" ledhaa "token" undho niyantristundi.
sambhaashana niyantrana tcp/iplo amalu cheyabadadu, mariyu avasaramaite nirvahinchadaaniki application poraku vadiliveyabadutundi. vistrutamgaa upayoginche HTTP/1.1 protocallo, client mariyu sarvar saadhaaranamgaa sagam-duplexes paddhatiloo panicheestaaru. puurti-duplexes operation kosam HTTP pipeliningku kooda maddatu istundi, conny chaalaa sarvarlu/pratinidhulu daanini sarigga nirvahinchalekapoyaru, mariyu puurti-duplexes upayoginchadaginadaa kaadaa anie tanikhi cheyadaaniki sambhaashana sampradimpula yantraangam ledhu, kabatti daani maddatunu chivariki chaalaa brouserlu tolaginchaayi.
samakaaleekarana paayintlu mariyu puna samakaaleekarana.
session pora rendu vaipula sambhaashanhalo "samakaaleekarana paayintlanu" choppinchadaaniki kooda anumatinchavacchu, mariyu current prasaranni nilipivese "puna samakaaleekarana" cheyadaaniki vaarini anumatinchavacchu, idhi samakaaleekarana binduvunu oka nirdishta viluvaku sett chestundi mariyu aaa point nundi prasaranni punahpraarambhistundi.
dheenini nija-samaya audeo/veediyo prasaaramlo upayoginchavacchu. dayta pravaahaaniki timestampulanu choppinchadaaniki samakaaleekarana paayintlanu upayoginchavacchu, mariyu kotta timestamp nundi praarambhinchadaaniki prasaranni reset cheyadaaniki resinchronisation upayoginchavacchu. udaaharanaku, veediyo stream audeo stream kante chaalaa venukabadi unte, sweekarinche vaipu veediyo streamlo resinchronization abhyardhananu jaarii cheyavachu, taruvaata timestamp nundi daani prasaranni punahpraarambhinchavachchu.
checkpointing cheyadaaniki kooda dheenini application upayoginchavacchu. synchronisation paayintlanu application dwara checkpoint kattubadi undani suuchimchadaaniki upayoginchavacchu, mariyu application crash ledhaa power fail ayina tarvaata, application checkpoint nundi tirigi vachindani mariyu transmissionnu tirigi praarambhinchavacchani suuchimchadaaniki recencranisation upayoginchavacchu.
idhi yea samayamloonainaa sambhaashanhaku antaraayam kaliginchadaaniki/tirigi praarambhinchadaaniki kooda upayoginchavacchu, application vaiphalyam kaaranamgaa kaadu, conny application pranaalika prakaram. application oka sambhaashanhaku antaraayam kaliginchavacchu, adhe sessionlo maroka sambhaashanhanu praarambhinchavacchu mariyu adhe sessionlo ledhaa maroka sessionlo munupati sambhaashanhanu tirigi praarambhinchavacchu.
okati ledhaa anthakante ekkuva sessionlalo bahula antaraayam kaliginche sambhaashanhalanu nirvahinchadaaniki session pora spashtamaina maddatunu kooda andinchavacchu. eee sambhaashanhalanu "karyakalapalu" antaaru. kaaryakalaapaalaku antaraayam kaliginchi, spashtamgaa tirigi praarambhinchavacchu. resinchronization dwara sambhaashanhalaku parokshamgaa antaraayam kaliginchadam mariyu tirigi praarambhinchadamtho poliste, kaaryaacharana maddatu eee sambhaashanalapai anuvartanaaniki saralamaina niyantrananu istundi.
tcp/aipi namuunaatoe polchandi.
tcp/aipi reference modal anedi osi modal yokka application ledhaa transport protocol semantics vivaraalatoe sambandham kaligi undadu, anduvalla session poranu pariganinchadu. saadhaarana ravana protocols (tcp, sttp) kuu sambandhinchi osi yokka session management, ravana-pora protokaallalo untundi, ledhaa application layer protocols yokka paridhiga pariganinchabadutundi. tcp/aipi yokka poralu operating scopes (application, host-tuu-host, network, link) yokka "vivaranalu" mariyu operating vidhanalu ledhaa dayta semantics yokka vivaranaatmaka "prescriptions" kaadu.