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VoIP Technology Explained
VoIP phone services reduce the voice transmission using speech data compression techniques and forward the telephone signals as digital audio over the Internet. VoIP phone services digitize voice into data packets, forward them over the Web and then reconvert them back into voice at their destination. This technology provides several advantages over prior era analog signals and as digital content can be better controlled, compressed, routed and managed. The steps involved in VoIP communication include the following:
1. An analog to digital converter (ADC) converts the analog voice to digital content (usually called signals or bits)
2. The digital content is compressed for speedy transmission. There are several compression formats available, however, SIP is the most common for VoIP transmission (and generally regarded as the industry standard)
3. The digital voice packets are further compressed into data packets using a real-time protocol (such as RTP over UDP).
4. A signal calls the destination user (ITU-T H323 is the most common signaling protocol)
5. Once at the destination user, the packets are disassembled, the content is extracted and the voice signals are converted back to analog and forwarded through a sound card or telephone
At a high level, there are two methods of public switched telephone networks (PSTN) – to – VoIP service types. Direct Inward Dialing (DID) connects callers directly to the VoIP user while Access Numbers require the caller to provide a telephone extension number for the VoIP user. A look and comparison at xxx is presented below. Circuit Switch Technology (PSTN)
The large telecommunications companies have historically used what is referred to as ‘circuit-switched technology’ to transport telephone calls. This technology method creates a fixed or permanent connection between the calling and the receiving parties for the entire duration of their call.
Common problems associated with circuit-switched technology are that it requires significant bandwidth for each call and it can only support telephone to telephone calls. Further, the hardware necessary to run and operate circuit-switched networks is expensive due, in large part, as voice and data transmissions must be carried separately by different wires and thus need separate hardware to accommodate the two traffic types. Higher cost and more complex hardware has resulted in many of the traditional telephone companies using parts of the Internet to connect PSTN calls. You have probably already placed or received a call using VoIP technology multiple times over without even knowing it.
The telephone companies pass along the costs of building and maintaining their circuit-switched networks to the consumer in the form of growing rates for their telephone services. While telecom companies are clearly achieving some efficiencies and cost savings by using publicly available Internet bandwidth, there does not seem to be a clear or logical cost savings past on to the consumer. VoIP Technology
VoIP transmits calls over the Internet (or more technically over an Internet Protocol (IP)). This may imply that the calls are transcending over the Web, or it may mean that the calls are traveling over private data networks that are using IP to transport the calls from one location to another.
With VoIP, voice signals are broken down into a stream of IP packets, compressed, optimized and then sent to their destination by various routes (in contrast to requiring a fixed or permanent route for the duration of the call). Routes are flexible and determined based on several factors including network congestion and bandwidth availability at any point in time.
When the voice packets are received at their destination, they are reassembled, decompressed, and converted back into a voice signals by a combination of software and hardware. Whether the call originated on a computer, traditional telephone, or an Integrated Access Device (IAD), and whether the call is going to be received on a PC, traditional telephone, or IAD, will determine the type of hardware and software necessary to complete the interaction. Broadband telephone companies and other service providers have been steadily improving VoIP software and hardware. Current VoIP voice-quality is quite comparable to the traditional circuit-switched technology and in fact many times the VoIP provider’s quality may be superior. VoIP services and functionality have grown and now support many new and interesting options, such as online user administration, account management, three-way calling, call forwarding, and extra/virtual numbers.
2. The digital content is compressed for speedy transmission. There are several compression formats available, however, SIP is the most common for VoIP transmission (and generally regarded as the industry standard)
3. The digital voice packets are further compressed into data packets using a real-time protocol (such as RTP over UDP).
4. A signal calls the destination user (ITU-T H323 is the most common signaling protocol)
5. Once at the destination user, the packets are disassembled, the content is extracted and the voice signals are converted back to analog and forwarded through a sound card or telephone
At a high level, there are two methods of public switched telephone networks (PSTN) – to – VoIP service types. Direct Inward Dialing (DID) connects callers directly to the VoIP user while Access Numbers require the caller to provide a telephone extension number for the VoIP user. A look and comparison at xxx is presented below. Circuit Switch Technology (PSTN)
The large telecommunications companies have historically used what is referred to as ‘circuit-switched technology’ to transport telephone calls. This technology method creates a fixed or permanent connection between the calling and the receiving parties for the entire duration of their call.
Common problems associated with circuit-switched technology are that it requires significant bandwidth for each call and it can only support telephone to telephone calls. Further, the hardware necessary to run and operate circuit-switched networks is expensive due, in large part, as voice and data transmissions must be carried separately by different wires and thus need separate hardware to accommodate the two traffic types. Higher cost and more complex hardware has resulted in many of the traditional telephone companies using parts of the Internet to connect PSTN calls. You have probably already placed or received a call using VoIP technology multiple times over without even knowing it.
The telephone companies pass along the costs of building and maintaining their circuit-switched networks to the consumer in the form of growing rates for their telephone services. While telecom companies are clearly achieving some efficiencies and cost savings by using publicly available Internet bandwidth, there does not seem to be a clear or logical cost savings past on to the consumer. VoIP Technology
VoIP transmits calls over the Internet (or more technically over an Internet Protocol (IP)). This may imply that the calls are transcending over the Web, or it may mean that the calls are traveling over private data networks that are using IP to transport the calls from one location to another.
With VoIP, voice signals are broken down into a stream of IP packets, compressed, optimized and then sent to their destination by various routes (in contrast to requiring a fixed or permanent route for the duration of the call). Routes are flexible and determined based on several factors including network congestion and bandwidth availability at any point in time.
When the voice packets are received at their destination, they are reassembled, decompressed, and converted back into a voice signals by a combination of software and hardware. Whether the call originated on a computer, traditional telephone, or an Integrated Access Device (IAD), and whether the call is going to be received on a PC, traditional telephone, or IAD, will determine the type of hardware and software necessary to complete the interaction. Broadband telephone companies and other service providers have been steadily improving VoIP software and hardware. Current VoIP voice-quality is quite comparable to the traditional circuit-switched technology and in fact many times the VoIP provider’s quality may be superior. VoIP services and functionality have grown and now support many new and interesting options, such as online user administration, account management, three-way calling, call forwarding, and extra/virtual numbers.
