Bungwe la Public Switched Network Network (PSTN) ndilo kusonkhanitsa kwapakati pazinthu zomwe zimagwiritsidwa ntchito pothandizira kulankhulana kwa voliyumu. PSTN imapereka chipatala chotchedwa Old Plain Old Telephone Service (POTS) - chomwe chimadziwika kuti utumiki wa foni - malo okhala ndi malo ena ambiri. Mbali za PSTN zimagwiritsidwanso ntchito pazinthu zogwirizanitsa Intaneti kuphatikizapo Digital Subscriber Line (DSL) ndi Voice over Internet Protocol (VoIP) .
PSTN ndi imodzi mwa njira zamakono za telephony - electronic voice communication. Ngakhale njira zoyambirira za telephony kuphatikizapo PSTN zonse zogwirizana ndi chizindikiro cha analog, makompyuta amakono a telephony amagwiritsa ntchito chizindikiro cha digito, amagwira ntchito ndi data ya digito, komanso amathandizira pa intaneti. Kutulutsidwa kwa Internet telephony kumapangitsa onse mawu ndi deta kuti agwirizane nawo maofesi omwewo, malonda omwe makampani opanga zamalonda padziko lonse akusuntha (makamaka chifukwa chachuma). Chovuta chachikulu pa intaneti ndi telephony kuti chikhale chodalirika kwambiri komanso chikhalidwe chapamwamba chomwe ma foni a chikhalidwe amakwaniritsa.
Mbiri ya PSTN Technology
Mauthenga a pafoni adakula padziko lonse lapansi m'ma 1900 pamene ma telefoni anakhala ozoloŵera m'nyumba. Ma telefoni akuluakulu amagwiritsidwa ntchito polemba chizindikiro cha analog koma pang'onopang'ono anakonzanso kugwiritsa ntchito zipangizo zamakono. Anthu ambiri amagwirizanitsa PSTN ndi mkuwa wopezeka m'nyumba zambiri ngakhale zipangizo zamakono za PSTN zimagwiritsanso ntchito zipangizo za fiber optic ndipo zimachokera mkuwa wokhayokha womwe umatchedwa "makilomita otsiriza" pakati pakhomo ndi wothandizira telecommunication. PSTN imagwiritsa ntchito SS7 kusonyeza protocol.
Manambala a PSTN am'nyumba amalowetsedwa m'zipinda zam'mwamba zomwe zimayikidwa m'nyumba pogwiritsa ntchito zingwe za telefoni ndi ojambulira RJ11. Malo osakhala nawo nthawi zonse amakhala m'malo oyenera, koma eni nyumba amatha kuika makina awo a telefoni ndi zidziwitso za magetsi.
PSTN imodzi imalumikiza makilogalamu 64 pamphindi (Kbps) yawunduka kwa deta. Mzere wa foni wa PSTN ukhoza kugwiritsidwa ntchito ndi ma modem ovomerezeka ojambula ovomerezeka kuti agwirizane ndi intaneti. M'masiku oyambirira a Webusaiti Yadziko Lonse (WWW) , iyi ndiyo njira yoyamba yopezera intaneti kwapakhomo koma inapangidwa osagwira ntchito ndi mautumiki apakompyuta a pa Intaneti. Kuphatikizana kwa intaneti kwasakanikirana ndi 56 Kbps.
PSTN vs. ISDN
Dongosolo la Integrated Services Network (ISDN) linakhazikitsidwa ngati njira ina yophatikizapo PSTN yomwe imapereka mauthenga a foni komanso chithandizo cha digito. ISDN inayamba kutchuka m'mabizinesi akuluakulu chifukwa cha kuthekera kwake kwothandizira mafoni ambirimbiri okhala ndi ndalama zochepa. Inaperekedwanso kwa ogula monga njira ina yopezera intaneti yomwe ikuthandiza 128 Kbps.
PSTN vs. VoIP
Voice over Internet Protocol (VoIP) , nthawi zina imatchedwanso IP telephony , idakonzedwa kuti idzasinthe maulendo a foni-switched a PSTN ndi a ISDN ndi paketi switched system pogwiritsa ntchito Internet Protocol (IP) . Mibadwo yoyamba ya misonkhano ya VoIP inakhudzidwa ndi kudalirika komanso nkhani zapamwamba koma pang'onopang'ono zakhala zikuyenda bwino.