INTRODUCTION
Since Networking became popular, it has attracted many developers to develop software applications for better communications than offered by plain text. Among these applications are those that support voice communication. In this project we have developed a voice communications application which offers a near real time point-to-point voice service providing virtual duplex voice communication.
Over the network, the two types of protocols available are connection oriented protocols and connectionless protocols. With connection oriented protocol, the network I/O on that connection is always with the same peer process while with the connectionless protocol, every network I/O operation can be with a different process on a different host. Moreover, a connectionless protocol doesn't guarantee that packets will arrive at the destination while connection oriented protocol guarantees a reliable delivery. An example of a connection-oriented protocol among the family of Internet protocols is the Transmission Control Protocol (TCP or TCP/IP).
Despite ensuring a somewhat safe and reliable delivery, a connection oriented protocol requires much higher bandwidth than the connectionless protocol because of the various checksum and parity calculations that it performs on individual packets. This becomes a problem when transmitting speech over the network because speech itself requires at least (8000samples/sec x 8bits/sample) 64Kbits/sec bandwidth uncompressed which is much higher than what most other network applications that uses TCP/IP can provide. Moreover, loosing a few speech packets during transmission will not significantly degrade the speech quality. Because of these reasons, a decision was made to use a connectionless protocol to transmit speech over the network.
Hence, in this application, the speech is transmitted under the User Datagram Protocol (UDP). UDP is a connectionless protocol among the family of the Internet Protocols. Although it is an unreliable protocol, UDP requires less bandwidth to transmit the data than a reliable protocol such as TCP would require and requires less time for handling by the operating system network services. Moreover, losing a few speech packets during transmission does not significantly degrade the SpeakEazy speech quality.
Topics :
MAIN PAGE
ABOUT THE APPLICATION
TOOLS USED
ALGORITHM
MINIMUM SYSTEM REQUIREMENTS
UPGRADATION POSSIBLE
DEVELOPED BY
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