Kungani ucingo lwe-SIP lubhalisa nge-VPN kodwa lungathumeli umsindo
Ukubhalisa nomsindo kuhamba ngezindlela ezihlukene. Landela ucingo olulodwa ngomhubhe ukuze ubone ukuthi i-PBX ingasebenzisa yiphi amakheli nokuthi i-RTP ima kuphi ngempela.
Ukubhalisa okuphumelelayo akusho lutho mayelana nomsindo. I-softphone ingagcina ukuxhumana okusemthethweni ne-PBX yasehhovisi amahora amaningi futhi ithumele ukuthula. Umhubhe uthwala kuphela amaphakethe umuntu awathumela ngamabomu kuwo, futhi ucingo lusebenzisa izindlela ezintathu ezihlukene: ukuxhumana, ukuhlelwa kwengxoxo kanye nokugeleza kwe-RTP. Uma uzehlukanisa, ukwehluleka kuwela endleleni eyodwa hhayi egameni elithi VPN.
Cabanga nge-laptop kwi-Wi-Fi yasekhaya ishayela isandiso sasehhovisi ngomhubhe ogunyaziwe. I-PBX iqinisekisa umsebenzisi, yamukela i-REGISTER, futhi isandiso sibonakala sitholakala, kodwa ucingo luxhuma ngokuthula okuphelele ohlangothini olulodwa.
Ukubhalisa kubopha othintwayo, hhayi indlela yemidiya
Isicelo se-REGISTER sicela umbhalisi ukuthi agcine ukuhlangana phakathi kwekheli lokurekhoda ne-URI eyodwa noma ngaphezulu yokuxhumana. Lokho kuhlangana kuphendula umbuzo omncane wokuthi ingxoxo entsha kufanele ithunyelwe kuphi manje. Akusho lutho ngokuthi imidiya ingena kuphi, futhi ukubhalisa okwamukelwe akufakazeli ukuthi i-INVITE yakamuva ithwala ikheli lemidiya elifinyelelekayo. Ukubhalisa futhi kuphelelwa isikhathi ngesibali sikhathi, ngakho ucingo oluyeka ukuvuselela lulahlekelwa izingcingo ezingenayo kuyilapho umhubhe walo usabonakala uphilile. Qaphela ukuphelelwa isikhathi kothintwayo hhayi isimo somhubhe.
Uma i-softphone ingemuva komhubhe, isihloko sothintwayo singathwala ikheli langasese. I-PBX eyalidlulisela kwelinye iphuzu lokugcina idala ingxoxo eqondile kunethiwekhi umuntu oshayiwe angakwazi ukufinyelela kuyo. Ukusetha i-rewrite_contact=yes endaweni yokugcina ye-PJSIP kwenza i-PBX ishintshe ikheli lomthombo elikubonile, futhi lokho kuvame ukuba umehluko phakathi kokukhala nokuphelelwa isikhathi.
I-INVITE inikela ngani futhi ubani angayisebenzisa
I-INVITE enomzimba we-SDP iphakamisa lapho oshayayo efuna ukuthola khona imidiya: ikheli, imbobo kanye nohlu lwama-codec. Oshayiwe uphendula ngekheli lakhe nembobo yakhe, bese kuthi uhlangothi ngalunye luthumele i-RTP lapho okunye kuphakamise khona. Uma oshayayo ephakamise ikheli elingu-192.168.x.x elikhona kuphela kunethiwekhi yakhe yasekhaya, oshayiwe akanayo indawo yokuthumela umsindo, kungakhathaliseki ukuthi ukusayinda kuhle kangakanani. Ukufihla kuyabhalwa kabusha izihloko ze-IP lapho amaphakethe ephuma kurutha, kodwa akukaze kubhale kabusha umbhalo ongaphakathi komzimba we-SDP.
Leyo gebe ichaza ucingo lwendabuko lwehlangothi elilodwa: ukusayinda kuyasebenza ngoba zombili iziphuzu zokugcina zifinyelela i-PBX, kanti umsindo wehluleka ngoba elinye iphuzu lokugcina latshelwa ukuthi lithumele ekhelini elikhona kuphela ngemuva kwenye i-NAT.
| Path | Who picks the address | Typical failure |
|---|---|---|
| REGISTER | Softphone, rewritten by the registrar if configured | Binding expires or points at a private address |
| INVITE and SDP | Each endpoint in its own offer or answer | Offer names a media address nobody can route to |
| RTP | PBX relay policy or the two endpoints | Port range blocked, or no return path |
Ubani othwala umsindo kuwukuzikhethela kokuhlelwa
Ukusayinda nemidiya kuyimisebenzi ehlukene. I-proxy ingahlala endleleni yokusayinda isikhathi sonke socingo futhi ingalokothi ithinte iphakethe le-RTP elilodwa. Ukuthi i-PBX iba umdluliseli wemidiya kuncike ekuhlelweni, hhayi ekubeni khona komhubhe.
Ngemidiya eqondile iziphuzu zokugcina zishintshana nge-RTP ngokwazo, lokho okusebenza kahle ku-LAN eyodwa futhi kubi lapho uhlangothi olulodwa lungemuva kwebanga elincane lemibobo.
Ukusetha i-direct_media=no kusunduza i-PBX endleleni yemidiya ukuze imilenze yomibili iphelele ekhelini elilawulayo, kushintsha umkhawulo wokudlulisela kanye ne-CPU ukuze kube nekheli elilindelekile. Uma lidlulisa, i-PBX kusafanele limemezele ikheli elifinyelelekayo. Kusibungu esinezixhumanisi eziningi, i-external_media_address ne-external_signaling_address ku-pjsip.conf zinquma okuzovela ku-SDP nakuzihloko ze-Via. Uma uzishiya zingasethiwe, i-PBX ingase inikeze ikheli layo le-LAN kumshayi ofunda ukuphela komhubhe kuphela.
Landela uhlangothi ngalunye ngaphambi kokuthinta izilungiselelo
Qala ngethebula lamasokhethi ku-PBX ngenkathi ucingo lusasebenza: i-ss -uanp | grep -E '5060|10000' ibonisa ukuthi izimbobo ze-RTP ziboshiwe yini nokuthi yiliphi ikheli lasendaweni elilisebenzisayo. Uma kungaboshiwe lutho ebangeni lemidiya, umdluliseli awusebenzi futhi iziphuzu zokugcina zikhuluma ngqo. Bese ubamba ohlangothini lwe-softphone nge-tcpdump -ni any -s0 udp portrange 10000-20000 -w rtp.pcap. Amaphakethe aphumayo angenawo amaphakethe angenayo anciphisa inkinga endleleni yokubuya noma ekhelini okwatshelwa uhlangothi olukude ukuthi lilisebenzise, futhi ukubamba okungenalutho kusho ukuthi imidiya ayikaze ifinyelele isixhumanisi somhubhe. Ukubamba kokusayinda nge-sngrep kuphendula ingxenye enye ngokubonisa umugqa wokuxhumana we-SDP njengoba wathunyelwa.
Qhathanisa ikheli elikulowo mugqa wokuxhumana nekheli uhlangothi olukude olungakwazi ngempela ukuhambisa kulo. Lokho kuqhathanisa okukodwa kuxazulula iningi lemibiko yomsindo wehlangothi elilodwa ngokushesha kunanoma yikuphi ukubuyekezwa kokuhlelwa.
Ukubethela kuma emaphethelweni omhubhe
I-SIP phezu kwe-TLS ivikela ukugxuma kokusayinda eyakhelwe kona, i-SRTP ivikela imidiya lapho iziphetho zombili zivumelana, futhi umhubhe uvikela ukuxhumana phakathi kweziphetho zawo. Akukho kulokhu okunikeza okunye. Ucingo olubethelwe ngaphakathi komhubhe lungaphuma esangweni ngombhalo ocacile lubheke ku-PBX, futhi lokho kusinqumo somklamo hhayi iphutha.
Ngaphambi kokuvala ithikithi, qinisekisa izinto ezintathu ngokulandelana: ukubhalisa kusha, i-SDP ithwala ikheli uhlangothi olukude olungafinyelela kulo, futhi amaphakethe ageleza nhlangothi zombili ezimbobeni zemidiya. Uma okunye kwalokhu kungamanga, umhubhe akusona isizinda senkinga. Lungisa indlela ehlulekile, bese uphinda ugijime ukubamba okufanayo ukuze uqinisekise ushintsho. Ukugcina ukubamba kwangaphambi nangemuva kwenza umbiko olandelayo wehlangothi elilodwa ube ukuhlolwa kwemizuzu emihlanu esikhundleni sentambama yonke.