I-VPN noma i-TURN relay: iyiphi ngempela ethwala ucingo lwe-WebRTC?
Umhubhe ushintsha indlela i-ICE eyibonayo; awuhlali lunikeza i-relay futhi awuhlinzeki i-signaling. Qhathanisa lokho okuphuma kwe-VPN kanye neseva ye-TURN okunikezayo.
Ikhasi liyala nge-VPN, kodwa ucingo aluxhumi nanini: amaphutha amabili ahlukene kubha yekheli elilodwa. Umhubhe washintsha indlela esetshenziswa isiphequluli; awuzange ube isevisi ye-signaling, iseva ye-STUN noma i-relay, futhi awunqumi ukuthi iyiphi ipheya yabangeneleli i-ICE ezokhetha. Ukwehlukanisa umsebenzi owenziwa yingxenye ngayinye yikho okuguqula “i-WebRTC ivinjiwe” engacaci ibe iphutha eliqondile.
Imisebenzi emine, umhubhe uthinta eyodwa kuphela
Uhlelo lushintshisana ngolwazi lwesikhathi ngohlelo oluthile lwe-signaling, futhi lowo umsebenzi wokuqala. I-ICE iqoqa amakheli abangeneleli futhi ihlola amapheya kuze kusebenze elilodwa, futhi lowo umsebenzi wesibili. I-STUN ivumela umlingani ukuthi azi ukuthi ithrafikhi yakhe ibonakala kanjani ngaphandle, kanti i-TURN inikeza i-relay ezimweni lapho kungekho indlela eqondile. Lezo zindima ezine zihlukile, futhi i-VPN ithinta amakheli nokuhlunga abahlangabezana nakho esikhundleni sokuhlinzeka noma yikuphi kukho.
Yingakho ukungena okuphumelelayo akusho lutho ngendlela yemidiya. I-signaling ivamise ukuhamba nge-HTTPS efanayo esevele isetshenziswa ikhasi, embobeni engu-443, kuyilapho imidiya ingahamba nge-UDP iye endaweni ehluke ngokuphelele.
Ukukhetha amakheli ayimfihlo kwenza ukudideka kube kubi kakhulu. Ikheli lomhubhe liwusizo kumlingani kuphela lapho lowo mlingani enendlela ebekiwe yokubuyela kulo; ukuba yimfihlo akusona ubufakazi bokufinyeleleka komunye nomunye, futhi iziphequluli azikuthathi kanjalo lapho zilahla abangeneleli abangahlolwa. Umngeneleli obonakala uyindawo yakho kungenzeka ungahlolwa ngakolunye uhlangothi. Kufanele kugwenywe lelo gebe ngaphambi kokuphetha ngokuthi umhubhe ulahla imidiya.
Qhathanisa okuphuma kwe-VPN ne-relay ye-TURN
Kokubili kudlulisela amaphakethe, yingakho kudidaniswa, futhi ithebula lokuqhathanisa elingenhla kufanele lifundwe ngekholomu ngayinye hhayi njengohlu lwezici. Ukunikezwa kwe-relay kuyinto yesikhathi ngasinye eyakhiwe isicelo esiqinisekisiwe; umhubhe uwumzila. Okunye kunemininingwane yokungena ephelelwa yisikhathi, okunye kunekheli lomlingani elifinyelelekayo noma elingafinyeleleki.
| Component | What it contributes | What it needs to work | What it cannot do |
|---|---|---|---|
| VPN exit | Changes the observed mapping and the route packets take | A working tunnel and a policy that permits the media transport | Allocate a relay or supply signaling |
| STUN server | Reports the mapped address a peer appears to use | Reachability from the client, on its configured transport | Carry media when a direct path fails |
| TURN server | Relays media through an authenticated allocation | Valid credentials, an allowed transport and sufficient capacity | Fix a missing ICE policy or an unauthorized client |
| Signaling channel | Carries offers, answers and candidate lists | Both peers reaching the same application endpoint | Establish connectivity by itself |
Izinombolo zamabhubhu zenza umehluko ube sobala. I-TURN ilalela ngokuzenzakalela ku-3478 ye-UDP ne-TCP naku-5349 ye-TLS, futhi inethiwekhi evumela u-443 kodwa ilahle lawo mabhubhu izohluleka ezingcingweni ezidluliswa nge-relay kuyilapho ukuphequlula kuqhubeka ngokujwayelekile. Ukushintsha umbhubhu we-VPN akulungisi lutho kulokho, ngoba imibhubhu ebalulekile ingeyesevisi ye-relay, hhayi umhubhe.
Funda ukuxilonga, bese uhlola ucingo
Iziphequluli ziveza ulwazi oludingayo ngaphandle kokubamba amaphakethe. Vula ikhasi lokuxilonga le-WebRTC lesiphequluli sakho, yenza ucingo, futhi ufunde ipheya yabangeneleli ekhethiwe esikhundleni sohlu oluqoqiwe: yiziphi izinhlobo zabangeneleli basekhaya nabakude ezikhethiwe, ngayiphi indlela yokuthutha nomndeni wamakheli, nokuthi indlela iqondile noma idlula ku-relay.
Kunokufunda okubili okufanele kwaziwe kusenesikhathi. Uma ipheya ekhethiwe iyi-host-to-host kumakheli ayimfihlo, imidiya ihlala endleleni ongacabanga ngayo; uma iyi-relay-to-relay, ucingo lusebenzisa umthamo we-relay futhi luncike ekutholakaleni kwale sevisi. Iphutha elimile ku-“kuyahlolwa” ngaphandle kwepheya ekhethiwe lisho ukuthi abangeneleli baqoqwa kodwa akekho ophumelele izivivinyo zokuxhumana.
Bese uqhathanisa lawo maphetha amabili ocwingweni olulodwa ngokushintsha isimo esisodwa esigunyaziwe kuphela, futhi wamukele umphumela ngemidiya noma idatha yezinhlangothi ezimbili hhayi ngesibonisi esithi “kuxhunyiwe”. Ukuqoqwa kwabangeneleli kuphumelela ezimweni eziningi ezingathwali ngisho ifreyimu eyodwa yomsindo. Phinda ucingo ngakolunye uhlangothi lwenguquko futhi ugcine kokubili ukubanjwa kokuxilonga, ngoba ukuqhathanisa ukugijima okubili kunikeza ulwazi olwengeziwe kunokufunda okukodwa kukodwa. Amaphetha afanayo, i-codec efanayo, ukuguquguquka okukodwa okushintshiwe.
Uhlelo olubeka ngamabomu inqubomgomo yokuthutha ye-ICE ekubeni relay lucela abangeneleli be-relay kuphela. Leso silungiselelo asidali i-relay futhi asilungisi imininingwane yokungena engekho; senza isidingo sicace, okusiza lapho othile esola i-VPN ngenqubomgomo ekhethwe isizindalwazi.
Gcina isimangalo sobumfihlo sincane njengobufakazi
Ukudalulwa kwabangeneleli kuncike enqubomgomo yesiphequluli nohlelo, hhayi esimweni somhubhe kuphela, futhi incazelo ye-W3C yokuxhumana kontanga ithatha ukuphathwa kwe-IP njengendaba yayo. Ngakho i-VPN exhunyiwe iyisisekelo esibuthakathaka sokuthembisa ukuthi ucingo ludalula ikheli elilodwa kuphela elikhethiwe. Ngisho abalingani ababili ngemuva komhubhe ofanayo bangakhetha indlela engashiyi umhlinzeki wendawo, okuyisikhathi esisodwa ukuthuthukiswa kobumfihlo kanye nokuvinjelwa kokuxhumana.
Ongakusho ngokunembile kuncane futhi kuyasiza: iyiphi ipheya yabangeneleli ekhethiwe, yikuphi ukuthutha okuyithwele, nokuthi leyondlela yahlala ngaphakathi komhubhe. Bhala lawo maqiniso amathathu ocwingweni olusebenzayo nolwehlulekile, futhi umehluko uvamise ukusho ingxenye okufanele ilungiswe.
Lapho ukuxhumana kusebenza, hlukanisa ukusebenza nokufinyeleleka. Ukulahlekelwa, ukubambezeleka, umugqa kanye ne-MTU kukhona ngaphansi kwepheya efanele yabangeneleli, futhi ukuthatha ucingo oluphazamukayo njengokwehluleka kokuxhumana kukubuyisela ohlwini lwabangeneleli ngaphandle kwesizathu.