Some key operators providing VoIP facility over internet are Skype, Yahoo voice chat, Google talk etc.
Shortcomings and Solutions
Some problems related with VoIP protocols is that they are not facilitated with the quality assurance of sequential data transfer among the huge traffic of cyber space. To add to the woo, this satellite communication mode may also have some propagation delay and adding to it that, the IP and the input devices must also take care of sharing and security of the packet data being received simultaneously.
So in many cases, the voice transfers include some jitter and disturbances. To get rid of this, normally jitter buffer is implemented in those systems. Various systems having firewall and translator cause problem and delay for voice transfers through IP. In order to overcome these problems VoIP operators adapt technologies like ICE or STUN.
For maintaining and improvising the quality of service of the VoIP in the era of heavy congestion, some tools and protocols are built to support it in that respect such as RTCP, SIP RTCP and MGCP extensions.