Internet Applications

RTP

Short for Real-Time Transport Protocol, an Internet protocol for transmitting real-time data such as audio and video. RTCP itself does not guarantee real-time delivery of data, but it does provide mechanisms for the sending and receiving applications to support streaming data. Typically, RTCP runs on top of the UDP protocol, although the specification is general enough to support other transport protocols.

UDP

UDP (User Datagram Protocol) is a simple OSI transport layer protocol for client/server network applications based on Internet Protocol (IP). UDP is the main alternative to TCP and one of the oldest network protocols in existence, introduced in 1980.

UDP is often used in videoconferencing applications or computer games specially tuned for real-time performance. To achieve higher performance, the protocol allows individual packets to be dropped (with no retries) and UDP packets to be received in a different order than they were sent as dictated by the application.

RTCP

It’s a companion protocol to RTP – the one used to send and receive most media over IP these days. It gives it a lightweight control mechanism that provides feedback to the sender about the quality of the data it is sending 

RTSP

Real Time Streaming Protocol (RTSP) is an application-level protocol for the transfer of real-time media data. The protocol is used to establish and control media sessions between end points by serving as a network-remote-control for time-synchronized streams of continuous media such as audio and video.

SMTP

Short for Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP. In addition, SMTP is generally used to send messages from a mail client to a mail server.

POP3

POP3, which is an abbreviation for Post Office Protocol 3, is the third version of a widespread method of receiving email. Much like the physical version of a post office clerk, POP3 receives and holds email for an individual until they pick it up. And, much as the post office does not make copies of the mail it receives, in previous versions of POP3, when an individual downloaded email from the server into their email program, there were no more copies of the email on the server; POP automatically deleted them.

IMAP4

IMAP (Internet Message Access Protocol) is richer in functionality than POP and is designed to allow clients to access and manage mailboxes on the server as if they were local. IMAP is a much more complex protocol than POP, with less client support. IMAP4 is the latest implementation of IMAP.

Difference between IMAP4 & POP3

The main difference between IMAP4 and POP3 is that with POP3 the messages are only stored temporarily on the mail server until they are downloaded to the email client where the messages are stored, manipulated, searched etc. With IMAP4 the messages are stored permanently on the server, and they are manipulated, searched etc on the mail server.

This difference means that, whichever computer a user uses to access his or her mail, the mail is always accessible when using IMAP4. With POP3, the user would have to copy the email client mailboxes onto the new PC to have access to their old mail. This makes it easier to have 'hot desking' (people just picking a free desk when they arrive at work) with an IMAP4 server like VPOP3 Enterprise.

References:

RTP. (n.d.). Retrieved from http://www.webopedia.com/TERM/R/RTP.html

Bradley , M. (n.d.). Udp. Retrieved from http://compnetworking.about.com/od/networkprotocolsip/g/udp-user-datagram-protocol.htm

Tsahi, L. (2011, July 14). Why do we need rtcp anyway?. Retrieved from http://blog.radvision.com/voipsurvivor/2011/07/14/why-do-we-need-rtcp-anyway/

Margaret, R. (n.d.). Real time streaming protocol (rtsp). Retrieved from http://searchvirtualdesktop.techtarget.com/definition/Real-Time-Streaming-Protocol-RTSP

SMTP. (n.d.). Retrieved from http://www.webopedia.com/TERM/S/SMTP.html

What is a pop3?. (n.d.). Retrieved from http://whatismyipaddress.com/pop3

What is imap4?. (2002, September 18). Retrieved from http://www.gordano.com/kb.htm?q=1444

What is imap4. (n.d.). Retrieved from http://wiki.pscs.co.uk/what_is;imap4

Done by: Tan Ting Hwee (TT01)