Question about internet network providers

Posted by: cat345 on 06 January 2012

Is it possible that sound quality can differ from the many internet network providers such as vTuner, Shoutcast, Frontier Silicon, etc..

 

Do internet radio streaming go through their own servers before reaching our internet providers?

Posted on: 06 January 2012 by Simon-in-Suffolk

Hi Cat345

No, the ISP   can't affect the sound quality of than the break up completely of the sound through slow data delivery.

Currently on IP4 we use (nearly universally) TCP for streaming as opposed to UDP multicast or unicast. This means that the protocol stacks in the sender and receiver take all the variability out of the network and so as long as there is sufficient throughput the receiver has enough data in its buffer to recover the payload and pass the audio data up the stack to the application.

So called internet radio or web radio is euthermism as it it is not broadcast on IP4, it is a peer session between server and client (te consumer's web radio).Ths is why until IPV6 gets rolled internt radio is relatively limited and low bandwidth. IPV6 supports more effectively multicast, which is data equivalent of data broadcasting across the nternet and so hidef web radio can be broadcast streamed to the masses without consuming vast amounts of capacity from the server.

Simon

 

 

 

Posted on: 06 January 2012 by cat345

Thanks for clarification Simon. I had to read your answer a few times to figure it out  but I understood that currently it is not possible to stream uncompressed hd audio even with a fast internet line but that would be possible in the near future.

 

I observe that sound quality vary from time to time with the few internet stations I listen to on a regular basis. As an example, the UK based Absolute radio can sound very good when heard in the ogg-flac format but SQ vary greatly from one day to another. 

Posted on: 07 January 2012 by Simon-in-Suffolk
Hi, it is possible to stream Hdif audio uncompressed, if the capacity at both ends is upto it, but the capacity required at the server end for more than a few users would become expensive in terms of server requirements and Internet access. With multicast streaming, (that is easier with IPV6) this will not be the case. The bandwidth required at the server end will be the same as for any one of the receivers. Clearly there is greater load through the Internet routing infrastructure. Therefore I am not expecting hidef streaming to become prevalent until ipv6 multicasting is enabled. This is going to take a few years. BT is starting to enable IPV6 (to run along side IPv4) on its networks from mid next year.

Currently  Internet web stations vary hugely in compression and therefore quality varies. Some setups will downgrade the quality ie increase the compression, if there is congestion on the server links to the Internet  or the established link is interrupted because of bandwidth congestion (because they are using TCP, rather UDP multicast).
I hope that makes some sense.
Simon
Posted on: 07 January 2012 by cat345

That is a very thoughtful information. Thanks!