VoIP (Voice over IP) provides new opportunities for those able to anticipate and act quickly enough to overcome the confusion that surrounds this remarkable technology as used Voice over IP. It is important to know how to use the VoIP (Voice over IP), you basically buy a device that visually is a black box that connects one side to the telephone equipment and the other to the PC ( computer ), but also IP phones are available. Of course you need to install a software for that device works. This device is almost always sold in the same stores that sell computers. There are two connection options:
- One party has VoIP (Voice over IP) and the other not.
- Both parties are VoIP (Voice over IP)
If both parties are VoIP (Voice over IP) call is free, it is called VoIP (Voice over IP) VoIP (Voice over IP), only have to dial the phone number and nothing else. If the caller only has VoIP (Voice over IP), then uses a card that is purchased online (online). The above card is a card of plastic or cardboard such as those sold in stores, rather it is a virtual card you buy and load on the Internet.
The model of Voice over IP consists of three main elements:
- The client - This element establishes and terminates voice calls. Encodes, packages and transmits the output information generated by the user's microphone. It also receives, decodes and reproduces the voice information input by the user's speakers or headphones. Note that the client component is available in two basic forms: the first is a suite of software running on a PC that you control through a graphical user interface (GUI) and the second client may be a "virtual" who resides in the gateway.
- Servers - The second element of Voice over IP is based on servers, which handle a wide range of operations, complex databases, in real time and outside it. These operations include user authentication, appraisal, accounting , pricing, collection, distribution of profits, routing, management 's overall service, charging customers, service control, registration of users and directory services among others.
- Gateways - The third element is formed by the Voice over IP gateways, which provide a communication bridge between users. The role of a main gateway is to provide the interfaces with appropriate traditional telephony, serving as a platform for virtual clients.
These teams also play an important role in access security, accounting, control of quality of service (QoS, Quality of Service) and improve it.
Characteristics of Voice over IP
For its structure provides the following standard features:
- Allows control of network traffic, so less chance of the occurrence of significant declines in the performance of data networks.
- Provides links to the traditional telephone network.
- Being supported on IP technology has the following advantages:
- Is independent of the type of network physics that supports it. Allows integration with existing large IP networks.
- Is independent of the hardware used.
- Lets be implemented in both software and hardware, with the particularity that the hardware would eliminate the initial impact for the common user.
Voice over IP Protocols
Today, there are two protocols for transmitting voice over IP, both define the way in which such devices must communicate with each other, and includes specifications for codecs (coder-decoder) audio to convert an audio signal to a digitized pad and vice versa.
H.323
H.323 is the standard established by the International Telecommunications Union (ITU) which is comprised of a highly complex and extensive protocol, which also include voice over IP, provides specifications for video-conferencing and real-time applications, including other variants.
Session Initiation Protocol (SIP)
Session Initiation Protocol (SIP) was developed by the IETF (Internet Engineering Task Force) specifically for IP telephony, which in turn takes advantage of other existing protocols to handle part of the process of conversion, a situation that applies to H.323 as it defines its own protocols bases.
The Standard Voice over IP
Long, those responsible for communications companies have in mind the possibility of using their data infrastructure for the transport of internal voice traffic the company . However, the emergence of new standards and the improvement and cheapening of voice compression technology, which is ultimately causing its implementation.
Having found that from a PC with elements multimedia , you can make phone calls over the Internet, we believe that IP telephony is little more than a toy, because the quality of voice that we obtain through Internet is very poor . However, if in our company have a data network that has a large enough bandwidth, we can also think of using that network for voice traffic between the various delegations of the company. The advantages we would get to use our network to transmit both voice and data are evident:
- Communications cost savings because calls between the various delegations of the company would go free.
Actually the integration of voice and data in one network is an old idea, have long since emerged solutions from different manufacturers, using multiplexers, WAN networks allow the use of business data (typically point connections to-point and frame-relay) for the transmission of voice traffic. The lack of standards and long-term depreciation of such solutions has not allowed a wide introduction of the same.
Example network connecting PBXs to Cisco routers that have VoIP support
Bookmarks