Me ya sa kiran SIP ke yin rajista a kan VPN amma bai aika sauti ba
Rajista da sauti suna bin hanyoyi daban-daban. Bi kira ɗaya ta cikin ramin don ganin waɗanne adireshi PBX zai iya amfani da su da kuma inda RTP ke tsayawa da gaske.
Rajista mai nasara ba ta faɗi kusan komai game da sauti ba. Wayar software na iya riƙe ingantaccen haɗi da PBX na ofis na sa'o'i kuma har yanzu tana ba da shiru. Ramin yana ɗaukar fakitin da wani ya aika cikinsa da gangan kawai, kuma kira yana amfani da hanyoyi uku daban-daban: haɗi, kafa tattaunawa, da magudanar RTP. Da zarar ka raba waɗannan, gazawar tana kan hanya ɗaya maimakon kalmar VPN.
Ka yi tunanin kwamfutar tafi-da-gidanka a Wi-Fi na gida tana buga tashar ofis ta hanyar rami da aka amince da shi. PBX yana tabbatar da mai amfani, yana karɓar REGISTER, kuma tashar tana bayyana a matsayin akwai, amma duk da haka kiran yana haɗuwa da shiru a gefe ɗaya.
Rajista tana ɗaure lambar sadarwa, ba hanyar watsa labarai ba
Buƙatar REGISTER tana roƙon mai yin rajista ya adana taswira tsakanin adireshin rikodin da ɗaya ko fiye da URI na sadarwa. Wannan taswirar tana amsa ƙaramin tambaya game da inda ya kamata a aika sabon tattaunawa a yanzu. Ba ta faɗi komai game da inda watsa labarai ya kamata ya kasance ba, kuma rajista da aka karɓa ba ta tabbatar da cewa INVITE na gaba yana ɗauke da adireshin watsa labarai da za a iya isa ba. Rajista kuma tana ƙarewa da ƙidayar lokaci, don haka wayar da ta daina sabuntawa tana rasa kira mai shigowa yayin da raminta ke ci gaba da kama da lafiya. Ka lura da ƙarewar sadarwa maimakon yanayin ramin.
Lokacin da wayar software take bayan ramin, kan sadarwa na iya ɗauke da adireshi na sirri. PBX da ke tura shi zuwa wani ƙarshen wuri yana ƙirƙirar tattaunawa da ta nufi hanyar da wanda aka kira ba zai iya isa ba. Sanya rewrite_contact=yes a ƙarshen wurin PJSIP yana sa PBX ya maye gurbin adireshin tushen da ya gani, kuma sau da yawa wannan shine bambanci tsakanin ringi da ƙarewar lokaci.
Abin da INVITE ke bayarwa da wanda zai iya amfani da shi
INVITE mai jikin SDP yana ba da shawara inda mai kira yake son karɓar watsa labarai: adireshi, tashar jiragen ruwa, da jerin codec. Wanda aka kira yana amsawa da adireshinsa da tasharsa, sannan kowane gefe yana aika RTP zuwa abin da ɗayan ya ba da shawara. Idan mai kira ya ba da shawarar adireshin 192.168.x.x wanda ke wanzuwa kawai a cikin hanyar sadarwar gidansa, wanda aka kira ba shi da inda zai aika sauti, komai tsaftar sigina. Masking yana sake rubuta kan IP yayin da fakiti ke barin na'urar tura, amma ba ya sake rubuta rubutun da ke cikin jikin SDP.
Wannan gibin yana bayyana kiran da aka sani na gefe ɗaya: sigina yana aiki saboda dukan ƙarshen biyu suna isa PBX, kuma sauti yana gazawa saboda an gaya wa ƙarshen ɗaya ya aika zuwa adireshin da ke wanzuwa kawai bayan wani 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 |
Wanda ke ɗaukar sauti zaɓi ne na tsari
Sigina da watsa labarai ayyuka ne daban-daban. Proxy na iya kasancewa a kan hanyar sigina duk kiran kuma bai taɓa ko ɗaya fakitin RTP ba. Ko PBX zai zama mai relay na watsa labarai ya dogara da tsarin, ba da kasancewar rami ba.
Da watsa labarai kai tsaye, ƙarshen biyu suna musayar RTP da kansu, wanda ke aiki da kyau a LAN ɗaya kuma mara kyau lokacin da gefe ɗaya ke bayan ƙaramin kewayon tashar jiragen ruwa.
Sanya direct_media=no yana tilasta PBX shiga hanyar watsa labarai don ƙafafu biyu su ƙare a adireshin da yake sarrafawa, yana musayar bandwidth da processor don adireshi da ake iya tsammani. Lokacin da yake relay, PBX dole ne har yanzu ya sanar da adireshin da ake iya isa. A kan mai masaukin cibiyoyin sadarwa da yawa, external_media_address da external_signaling_address a cikin pjsip.conf suna ƙayyade abin da zai bayyana a SDP da kuma a kan hannun Via. Idan ba ka saita su ba, PBX na iya ba da adireshinsa na LAN ga mai kira wanda hanyarsa kaɗai ita ce gefen nesa na ramin.
Bi kowace hanya kafin ka taɓa saituna
Fara da teburin soket a kan PBX yayin da kira ke gudana: ss -uanp | grep -E '5060|10000' yana nuna ko an ɗaure tashoshin RTP da kuma wace adireshin gida suke amfani. Idan babu abin da aka ɗaure a cikin kewayon watsa labarai, relay ɗin ba ya aiki kuma ƙarshen biyu suna magana kai tsaye. Sannan ka yi rikodin a gefen wayar software da tcpdump -ni any -s0 udp portrange 10000-20000 -w rtp.pcap. Fakitin da ke fita ba tare da fakitin da ke shigowa ba suna taƙaita matsalar zuwa hanyar dawowa ko zuwa adireshin da aka gaya wa gefen nesa ya yi amfani da shi, kuma rikodin fanko yana nufin watsa labarai bai taɓa isa fuskar ramin ba kwata-kwata. Rikodin sigina da sngrep yana amsa rabin ɗayan ta hanyar nuna layin haɗin SDP yadda aka aika shi.
Kwatanta adireshin da ke cikin wannan layin haɗin da adireshin da gefen nesa zai iya yi masa hanya da gaske. Wannan kwatancen ɗaya yana warware yawancin rahotannin sauti na gefe ɗaya da sauri fiye da kowane bitar tsari.
Ƙirƙirar sirri tana tsayawa a gefen ramin
SIP a kan TLS yana kare tsallen sigina da aka saita don shi, SRTP yana kare watsa labarai lokacin da ƙarshen biyu suka amince da shi, kuma ramin yana kare zirga-zirga tsakanin ƙarshensa. Babu ɗaya daga cikinsu da ke ba da sauran. Kiran da aka ɓoye a cikin ramin na iya barin ƙofar a cikin rubutu bayyananne zuwa PBX, kuma wannan shawara ce ta ƙira ba lahani ba.
Kafin ka rufe tikitin, tabbatar da abubuwa uku a jere: rajista sabo ne, SDP yana ɗauke da adireshin da gefen nesa zai iya isa, kuma fakiti suna gudana a duka hanyoyi a tashoshin watsa labarai. Idan ɗaya daga cikinsu ƙarya ne, ramin ba shine inda matsalar take ba. Gyara hanyar da ta gaza, sannan ka sake gudanar da wannan rikodin don tabbatar da canjin. Ajiye rikodin na kafin da bayan yana mai da rahoton gefe ɗaya na gaba bincike na minti biyar maimakon dukan yamma.