 rE: Mady
Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or other paket switched network. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.
Internet telephony refers to communications services — voice,
facsimile, and/or voice-messaging applications — that are transported
via the Internet, rather than the public switches telephone network (PSTN). The basic steps involved in originating an Internet telephone
call are conversion of the analog voice signal to digital format and
compression/translation of the signal into internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end.
VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio via an audia stream.
Codec use is varied between different implementations of VoIP (and
often a range of codecs are used); some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs.
Source: http://en.wikipedia.org/wiki/Voice_over_Internet_Protocol
Ager app Pakistan se telephone to telephone calls ki baat kar
rahay hain internationally tou yahan pe ab sastay call rates hain ,1
....100 rupess k telephone card se maximum 1 hour (ya is se bhi zyada)
baat hojati hai kisi bhi country main. jab k mobile se bhi 100 rupess main half hour baat hojati hai internatinal landlines pe.
aur agar app pc to pc call ki baat kar rahay hain tou iske
liyain broadband (cable net) se kisi bhi software k zaryai (i.e, yahoo,
skype, windows live) free baat ki jasakti hai.
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