Isimo esidabukisayo ngokuvikeleka kwe-inthanethi ngesathelayithi

Engqungqutheleni edlule kwethulwe Isigqoko Esimnyama umbiko, ezinikezelwe ezinkingeni zokuphepha kumasistimu okufinyelela ku-inthanethi asathelayithi. Umbhali wombiko, esebenzisa isamukeli se-DVB esingabizi, ubonise ukuthi kungenzeka kunqandwe ithrafikhi ye-inthanethi esakazwa ngeziteshi zokuxhumana ngesathelayithi.

Iklayenti lingaxhuma kumhlinzeki wesathelayithi ngamashaneli asymmetric noma ama-symmetric. Endabeni yesiteshi esingalingani, ithrafikhi ephumayo evela kuklayenti ithunyelwa ngomhlinzeki wasemhlabeni futhi itholwe ngesathelayithi. Kuzixhumanisi ezilinganayo, ithrafikhi ephumayo nengenayo idlula yisathelayithi. Amaphakethe aqondiswe kwiklayenti athunyelwa ngesathelayithi kusetshenziswa ukusakazwa kokusakaza okufaka ithrafikhi evela kumakhasimende ahlukene, kungakhathaliseki ukuthi akuyiphi indawo. Kwakungenzima ukunqanda ithrafikhi enjalo, kodwa ukuvimbela ithrafikhi evela kuklayenti ngesathelayithi kwakungelula kangako.

Ukushintshanisa idatha phakathi kwesathelayithi kanye nomhlinzeki, ukudluliselwa okugxilile kuvame ukusetshenziswa, okudinga ukuthi umhlaseli abe amashumi amaningana amakhilomitha ukusuka kwingqalasizinda yomhlinzeki, futhi asebenzise ububanzi befrikhwensi ehlukile kanye namafomethi wombhalo wekhodi, ukuhlaziya okudinga imishini yomhlinzeki ebizayo. . Kodwa noma ngabe umhlinzeki esebenzisa i-Ku-band evamile, njengomthetho, ama-frequencies ezinkomba ezahlukene ahlukile, okudinga ukusetshenziswa kwesitsha se-satellite sesibili nokuxazulula inkinga yokuvumelanisa ukusakaza ukuze kunqamule kuzo zombili izinkomba.

Kwakucatshangwa ukuthi ukuhlela ukunqanyulwa kokuxhumana ngesathelayithi, kwakudingeka imishini ekhethekile, ebiza amashumi ezinkulungwane zamaRandi, kodwa empeleni ukuhlasela okunjalo kwenziwa kusetshenziswa. i-DVB-S evamile ishuna yethelevishini yesathelayithi (TBS 6983/6903) kanye ne-parabolic antenna. Isamba sezindleko zekhithi yokuhlasela cishe sasilinganiselwa ku-$300. Ukuze ukhombe uthi kumasathelayithi, kwasetshenziswa ulwazi olutholakala esidlangalaleni mayelana nendawo yamasathelayithi, futhi ukuze kutholwe iziteshi zokuxhumana, kwasetshenziswa uhlelo olujwayelekile oluklanyelwe ukucinga iziteshi ze-TV zesathelayithi. I-antenna yakhomba isathelayithi futhi kwaqala inqubo yokuskena Ku-band.

Iziteshi zihlonzwe ngokuhlonza amabanga aphezulu kumafrikhwensi omsakazo abebonakala kumsindo wangemuva. Ngemva kokuhlonza inani eliphakeme, ikhadi le-DVB lalungiswa ukuze litolike futhi lirekhode isignali njengokusakazwa kwevidiyo yedijithali evamile kumabonakude wesathelayithi. Ngosizo lokuhlangana kokuhlola, imvelo yethrafikhi yanqunywa futhi idatha ye-inthanethi yahlukaniswa nomabonakude wedijithali (ukusesha okuvinjelwe kwasetshenziswa endaweni yokulahla idoti elikhishwe ikhadi le-DVB kusetshenziswa imaski ye-“HTTP”, uma itholakele, kwacatshangwa ukuthi ishaneli enedatha ye-inthanethi itholakele).

Ucwaningo lwethrafikhi lubonise ukuthi bonke abahlinzeki be-inthanethi besathelayithi abahlaziyi abakusebenzisi ukubethela ngokuzenzakalelayo, okuvumela ukulalela kwethrafikhi okungaphazanyiswa. Kuyaphawuleka ukuthi izexwayiso mayelana nezinkinga zokuphepha ze-inthanethi zesathelayithi eshicilelwe eminyakeni eyishumi edlule, kodwa kusukela ngaleso sikhathi isimo asishintshile, naphezu kokwethulwa kwezindlela ezintsha zokudlulisa idatha. Ukushintshela kuphrothokholi entsha ye-GSE (Generic Stream Encapsulation) yokuvala ithrafikhi ye-inthanethi kanye nokusetshenziswa kwezinhlelo eziyinkimbinkimbi zokumodulation ezifana nokumodeshiswa kwe-amplitude okuyi-32-dimensional kanye ne-APSK (Phase Shift Keying) akwenzanga ukuhlasela kube nzima kakhulu, kodwa izindleko zemishini yokunqamula. manje lehlile lisuka ku-$50000 laya ku-$300.

Ukuhlehla okubalulekile lapho kuthunyelwa idatha ngeziteshi zokuxhumana ngesathelayithi ukubambezeleka okukhulu kakhulu ekulethweni kwephakethe (~700 ms), okuphindwe kashumi kunokubambezeleka lapho kuthunyelwa amaphakethe ngamashaneli okuxhumana asemhlabeni. Lesi sici sinemithelela emibi emibili ebalulekile ekuvikelekeni: ukuntuleka kokusetshenziswa okubanzi kwama-VPN kanye nokuntuleka kokuvikelwa ekulweni ne-spoofing (ukushintsha iphakethe). Kuyaphawulwa ukuthi ukusetshenziswa kwe-VPN kunciphisa ukudluliselwa cishe ngama-90%, okuthi, kucatshangelwa ukubambezeleka okukhulu ngokwabo, kwenza i-VPN ingasebenzi kahle ngeziteshi zesathelayithi.

Ukuba sengozini kwe-spoofing kuchazwa iqiniso lokuthi umhlaseli angakwazi ukulalela ngokuphelele ithrafikhi eza kulowo ohlukunyeziwe, okwenza kube nokwenzeka ukunquma izinombolo zokulandelana kumaphakethe e-TCP ahlonza ukuxhumana. Lapho uthumela iphakethe lomgunyathi ngesiteshi sasemhlabeni, cishe kuqinisekisiwe ukuthi lifika ngaphambi kwephakethe langempela elisakazwa ngeshaneli yesathelayithi enokubambezeleka okude futhi ngaphezu kwalokho lidlula kumhlinzeki wezokuthutha.

Okuqondiwe okulula kakhulu kokuhlaselwa kwabasebenzisi benethiwekhi yesathelayithi ithrafikhi ye-DNS, i-HTTP engabetheliwe kanye ne-imeyili, okuvamise ukusetshenziswa amaklayenti angabhaliwe. Ku-DNS, kulula ukuhlela ukuthunyelwa kwezimpendulo ze-DNS eziqanjiwe ezixhuma isizinda neseva yomhlaseli (umhlaseli angakhiqiza impendulo engelona iqiniso ngokushesha ngemva kokuzwa isicelo kuthrafikhi, kuyilapho isicelo sangempela kusafanele sidlule kumhlinzeki ohlinzekayo. ukuhamba kwesathelayithi). Ukuhlaziywa kwethrafikhi ye-imeyili kukuvumela ukuthi ubambe imininingwane eyimfihlo, isibonelo, ungaqalisa inqubo yokuthola iphasiwedi kuwebhusayithi futhi uhlole ithrafikhi umlayezo othunyelwe nge-imeyili ngekhodi yokuqinisekisa yomsebenzi.

Ngesikhathi sokuhlolwa, cishe i-4 TB yedatha esakazwa amasathelayithi ayi-18 yabanjwa. Ukulungiselelwa okusetshenzisiwe ezimeni ezithile akuzange kunikeze ukucasuka okuthembekile kokuxhumeka ngenxa yesilinganiso esiphezulu sesignali-kuya-kumsindo kanye nokwamukela amaphakethe angaphelele, kodwa ulwazi oluqoqiwe belanele ekonakaleni. Ezinye izibonelo zalokho okutholwe kudatha ebanjiwe:

• Ulwazi lokuzulazula nenye idatha ye-avionics edluliselwe endizeni iye yabanjwa. Lolu lwazi aluzange ludluliselwe ngaphandle kokubethela, kodwa futhi esiteshini esifanayo nethrafikhi yenethiwekhi evamile ebhodini, lapho abagibeli bethumela khona imeyili futhi baphequlula amawebhusayithi.
• Iseshini ye-Cookie yomlawuli wejeneretha yomoya eningizimu ye-France, oxhume kusistimu yokulawula ngaphandle kokubethela, iye yaphazanyiswa.
• Ukucobelelana ngolwazi mayelana nezinkinga zobuchwepheshe zomkhumbi kawoyela waseGibhithe kwatholakala. Ngaphandle kolwazi lokuthi umkhumbi ngeke ukwazi ukuya olwandle isikhathi esingangenyanga, kutholwe imininingwane mayelana negama nenombolo yepasi kanjiniyela obhekele ukulungisa le nkinga.
• Umkhumbi wawudlulisa ulwazi olubucayi mayelana nenethiwekhi yawo yendawo esekwe ku-Windows, okuhlanganisa nedatha yokuxhumana egcinwe ku-LDAP.
• Ummeli waseSpain uthumele iklayenti incwadi enemininingwane yecala elizayo.
• Ngesikhathi sokunqamuka kwezimoto eziya esikebheni sikasozigidi waseGreece, iphasiwedi yokuthola i-akhawunti ethunyelwe nge-imeyili ezinsizeni ze-Microsoft iye yabanjwa.

Source: opennet.ru