VoIP Network Protocol Support
There are several protocols to support VoIP networks, among others:
Protocol TCP / IP (Transfer Control Protocol / Internet Protocol) are a protocol used on the Internet. This protocol consists of two major parts, namely TCP and IP.
Application layer: The main function of this layer is to transfer files. Transfer files from a system different to other systems require a control system to overcome the mismatch of different file systems – different. This protocol deals with the application. One example application that has been known as HTTP (Hypertext Transfer Protocol) for web, FTP (File Transfer Protocol) to transfer files, and TELNET virtual terminal for long distance.
TCP (Transmission Control Protocol); in the transmit data in two Transport layer protocols are TCP and UDP role. TCP is a connection-oriented protocol which means maintaining reliability communications relationships end-to-end. The basic concept of the workings of TCP is sent and receives segments of length information data vary on an internet datagram. TCP guarantees reliability of communication links for doing repairs to damaged data, lost or send errors. This is done by giving the serial number on every packet sent and requires a positive response signal from the receiver of the ACK signal (acknoledgment). If a signal ACK is not received at a specific time interval, then the data will send back. On the receiving side, the serial number was useful to prevent errors and duplication of data sequence data. TCP also has a mechanism of control in a way follow to include information in the ACK signal on the limited number of data packets that are transmitted in each segment may be received successfully. In the VoIP connection, TCP is used at the time of signaling. TCP is used to guarantee a call to the session setup signaling. TCP is not used for sending voice data in VoIP due to a VoIP data communication handling data that has been delayed more important than the lost packet handling.
User Datagram Protocol (UDP), UDP is one of the main protocols over IP is a transport protocol that is simpler than TCP. UDP is used for situations that are not concerned with reliability mechanisms. UDP header contains only four fields namely source port, destination port, length, and UDP checksum in which the function is similar to TCP, but the facilities at the UDP checksum are optional. UDP on VoIP is used to transmit audio streams are transmitted on a continuous. UDP used on VoIP due to the delivery of streaming audio, which lasted continuously prioritize data transfer speed in order to arrive at the destination regardless of the existence of a lost package even reach 50% of the number of packets sent. (VoIP fundamentals, Davidson Peters, Cisco Systems, 163) Because UDP can transmit streaming data quickly, then the VoIP technology UDP is the one important protocol that is used as a header on besides RTP and IP data delivery. To reduce the number of packets lost during transmission of data (because there is not the retransmission mechanism) then the VoIP technology the data transfer is mostly done on a private network.
Internet Protocol (IP) Internet Protocol communications system designed to interconnect computers in a network packet switched. On TCP / IP network, a computer is identified by an IP address. Each computer has a unique IP address, each different from each other. This is done to prevent errors in data transfer. Finally, protocol access data directly related to the physical media. Generally, the protocol is to handle error detection during data transfer. For data communications, Internet protocol implements two basic functions are addressing and fragmentation. One of the important things in the IP in the delivery of information is a method of addressing sender and receiver. There are currently addressing standards that have been used, IPv4 with the address consists of 32 bits. The number of IPv4 addresses is expected to be made with sufficient IP address is not so in the next few years will be implemented and a new addressing system that uses 128-bit IPv6 addressing system.
