Sacoin grows with IP Centrex Solution from TELES More and more network operators rely on IP Centrex Systems
Sacoin, communication network solutions provider based in Oering near Hamburg, has opted for an IP Centrex solution from TELES. This solution… →
VoIP closed systems (as opposed to Open Standards (such as SIP, H.323 or MGCP)
AOL, Yahoo, and Apple all offer "voice chat" capability via their instant messaging networks. These systems are closed and for the most part unable to interoperate with other, standards-based products and may use undocumented protocols. However, even where the protocols are known or have been reverse-engineered, the audio codecs are proprietary. It is known that AOL's voice chat uses codecs from Qualcomm, Yahoo's uses TrueSpeech from DSP Group, and Apple's uses PureVoice QCELP.
The popular Skype service is similarly closed. It is known to use three audio codecs: iLBC (Internet Low-Bitrate Codec) and iSAC (Internet Speech and Audio Coder) from GlobalIPSound, and a third as-yet unidentified codec. The Skype protocols have not been reverse-engineered.
VoIP Glossary
