Computer Networks - Multimedia

Multimedia

These are my notes... RAR! If there's any issues give me a buzz because some stuff might not be clear enough.

Most multimedia is transmitted via TCP or UDP. It may also be transmitted via RTP and RTCP, but they're just protocols built on UDP - in fact, sometimes they're classified as being part of the application layer. Anyway, let's find out what all of this means...

Computer Networks - An Introductory Overview

What is a computer network?

To a user - something that allows applications to talk to each other. They have an idea as to what the infrastructure should allow them to do. Email and web browsing should be reliable. Internet banking should also be secure. Internet radio, voice over IP and video streaming should have quality. With VoIP however you also want low latency (delay) too, as opposed to internet radio. The demands of the network depend on what type of application you want to run.

Computer Networks - Applications

Network Applications

Computer networking? There's an app for that.

A network applications is a program that communicates over a network but runs on end systems, not core network devices. You can't install skype on a router!

There are 4 distinct architectures for network apps:

Computer Networks - Switching, Delays and Performance

Switching, Delays and Performance

Switching

A network is a mesh of routers connected, There are 2 basic ways of transferring packets through a network:

• Circuit switching:

Computer Networks – Play-out Delay

Internet Phone: Fixed Play-out Delay

With this, the receiver attempts to play out each chunk of data at exactly qms after the chunk was generated.

• This chunk has a time stamp, t: So the play-out chunk is at t+q
• If the chunk arrives after t+q, then the data arrives too late for play-out – the data is LOST!

Computer Networks - Multimedia

What is Multimedia?

So what exactly is multimedia? well the truth is – nobody knows!! This is because its nothing but binary data – except for audio and video which varies, and is commonly in analogue.