Isimo esidabukisayo ngokuphepha kwe-Intanethi nge-satellite

IBlack Hat yafaka umbiko ngezindaba zokuphepha ku izinhlelo zokufinyelela ku- I-inthanethi yesathelayithi. Umbhali wombiko ikhombise ikhono lokunqanda ithrafikhi ye-Intanethi idluliswa ngeziteshi zokuxhumana zesathelayithi usebenzisa isamukeli sezindleko eziphansi se-DVB.

Ngalokhu, ukhombisile ukuthi akunzima ukuvimba ithrafikhi ethunyelwe, kepha ukuthi kunenkinga ethile ekunqandeni ithrafikhi ethunyelwe ngesathelayithi ishiya iklayenti.

Encazelweni yakhe uyasho ukuthi iklayenti lingaxhuma kumhlinzeki wesathelayithi ngokusebenzisa iziteshi ezilinganayo noma ezilinganisiwe:

• Endabeni yesiteshi esilinganiselwe, ithrafikhi ephumayo yekhasimende ithunyelwa ngomhlinzeki wasemhlabeni futhi itholwe ngesathelayithi.
• Eziteshini ezihambisanayo, ithrafikhi engenayo nephumayo idlula kusathelayithi.

Amaphakethe aqondiswe kwiklayenti athunyelwa evela kusathelayithi ngokudluliswa kokusakazwa, okubandakanya ukuhamba kwamakhasimende ahlukahlukene, kungakhathalekile ukuthi zikuphi.

Ukushintshaniswa kwedatha phakathi kwesathelayithi nomhlinzeki, ukuhanjiswa okugxile kuvame ukusetshenziswa, okudinga ukuthi umhlaseli abe ngamashumi amakhilomitha ambalwa ukusuka kwingqalasizinda yomhlinzeki, futhi kusetshenziswa amabanga ehlukene ezimo namafomethi wokubhala. Ukuhlaziywa kudinga imishini ebizayo evela kumthengisi.

Kepha noma ngabe umhlinzeki esebenzisa i-Ku band ejwayelekile, njengomthetho, amaza ezinkomba ezihlukile ahlukile, adinga isitsha sesathelayithi sesibili ukubamba kuzo zombili izinkomba nokuxazulula inkinga yesikhathi sokudlulisa.

Bekucatshangwa ukuthi kudingeka imishini ekhethekile ukunqanda ukuxhumana ngesathelayithi, kubiza amashumi ezinkulungwane zamaRandi, kepha empeleni, kusho ukuhlasela kwenziwe kusetshenziswa ishuna ejwayelekile ye-DVB-S yethelevishini yethelevishini (i-TBS 6983/6903) kanye ne-antenna efanisayo.

Izindleko eziphelele zethimba lesiteleka zazilinganiselwa ku- $ 300. Imininingwane etholakala esidlangalaleni ngendawo yeziphuphutheki isetshenziselwe ukuqondisa i-antenna kuma-satellite, futhi uhlelo olujwayelekile lokufuna iziteshi zethelevishini ze-satellite lusetshenzisiwe ukuthola iziteshi zokuxhumana.

I-antenna yayiqondiswe kusathelayithi futhi kwaqala inqubo yokuskena kwe-Ku-band.

Iziteshi zikhonjwe ngokuhlonza iziqongo ku-RF spectrum, ezibonakala kumongo womsindo ojwayelekile. Ngemuva kokukhomba inani eliphakeme, ikhadi le-DVB lalungiswa ukuze lihumushe futhi liqophe isignali njengomsakazo ojwayelekile wevidiyo yedijithali yethelevishini yesathelayithi.

Ngosizo lwemikhawulo yokuhlola, ubunjalo bethrafikhi babunqunywa futhi imininingwane ye-Intanethi yahlukaniswa nethelevishini yedijithali (ukuseshwa kwe-banal endaweni yokulahla inhlabathi ekhishwe yikhadi le-DVB kusetshenziswe kusetshenziswa imaski «HTTP», uma itholakele , kwakucatshangwa ukuthi kutholakala isiteshi esinemininingwane ye-Intanethi).

Uphenyo lomgwaqo lukhombisile lokhokwahlaziywa bonke abahlinzeki be-inthanethi be-satellite ungasebenzisi ukubethela ngokuzenzakalela, evumela umhlaseli ukuthi ezwe isiminyaminya ngaphandle kwesithiyo.

Ukushintshela kuphrothokholi entsha ye-GSE (Generic Stream Encapsulation) yokuhlanganisa ithrafikhi ye-Intanethi kanye nokusetshenziswa kwezinhlelo zokushintshashintsha kwezwi ezinjenge-32-D amplitude modulation kanye ne-APSK (Phase Shift Keying) akuzange kube nzima ukuhlaselwa, kepha izindleko zemishini ukubanjwa manje kuncishisiwe kusuka ku- $ 50,000 kuya ku- $ 300.

Ububi obukhulu lapho idatha idluliswa ngeziteshi zokuxhumana zesathelayithi ukulibaziseka okukhulu kakhulu ekulethweni kwamaphaselas (~ 700 ms), okuyizikhathi eziphindwe kayishumi kunokubambezeleka kokuthumela amaphakethe ngeziteshi zokuxhumana zasemhlabeni.

Izinhloso ezilula zokuhlaselwa kwabasebenzisi be-satellite yi-DNS, ithrafikhi ye-HTTP engabhalwanga, ne-imeyili, ejwayele ukusetshenziswa amaklayenti angabhalwanga.

Nge-DNS, kulula ukuhlela ukuthumela izimpendulo ezingezona ze-DNS ezixhumanisa isizinda neseva yomhlaseli (umhlaseli angenza impendulo engeyikho ngokushesha ngemuva kokulalela isicelo kuthrafikhi, ngenkathi isicelo sangempela kusamele sidlule kumhlinzeki ithrafikhi yesathelayithi).

Ukuhlaziywa kwethrafikhi ye-imeyili kuvumela ukucabhela kolwazi oluyimfihloIsibonelo, ungaqala inqubo yokutakula iphasiwedi kusayithi bese uhlola ithrafikhi ethunyelwe nge-imeyili enekhodi yokuqinisekisa yokusebenza.

Ngesikhathi sokuhlolwa, cishe i-4 TB yedatha yabanjwa, yadluliselwa ngamasathelayithi ayi-18. Ukucushwa okusetshenziswe ezimweni ezithile akuzange kunikeze ukunqanyulwa okuthembekile kokuxhuma ngenxa yesilinganiso esiphansi sesiginali-kuya-msindo nokwamukelwa kwamaphakethe angaqediwe, kepha imininingwane eqoqiwe ibanele ukwazi ukuthi idatha ibucayi.

Ezinye izibonelo zalokho okutholakele kudatha ebanjiwe:

• Imininingwane yokuzulazula neminye imininingwane ye-avionics edluliselwe endizeni ibanjiwe. Lolu lwazi aludluliswanga kuphela ngaphandle kokubethela, kepha futhi nasesiteshini esifanayo nethrafikhi yenethiwekhi ejwayelekile ebhodini, lapho abagibeli bethumela khona imeyili futhi bapheqa amawebhusayithi.
• Ukushintshaniswa kolwazi ngezinkinga zobuchwepheshe ethangini laseGibhithe kwabanjwa. Ngaphezu kwemininingwane yokuthi umkhumbi awukwazanga ukufakwa olwandle isikhathi esingangenyanga, kwatholakala imininingwane ngegama nenombolo yepasipoti yonjiniyela obhekene nokuxazulula inkinga.
• Ummeli waseSpain uthumele incwadi kwiklayenti enemininingwane yecala elizayo.