Why Skype Audio quality is better than Asterisk

Hi all,

I just figured out skype audio quality is better than Asterisk. I have a DSL link which is directly connected to Asterisk server. I tried calling people outside who are also using broadband connections. but the audio quality is very poor.
What is the reason for this?
Any suggestions?
Do you think our core network(service provider side) should route voice packets with high priority(using MPLS)?
If yes how skype is doing their own thing?

Thanks all,

Hi…seems like nobody interesting in this posting…anyway anyone got a differnt view on this

there’s no doubt that the call quality on Skype is mostly superb. they do their own thing, use their own codec and keep it closed … especially now eBay own them.

but then i have a 3500/448 DSL connection and have no problems with call quality using G729. no QoS on my SoHo office either, and we regularly do call conferences with up to 6 people.

before you use Skype, go read the EULA, especially the bit where you agree to let the Skype network use your PC and bandwidth to facilitate other people’s calls.

btw, 28 minutes and you think no-one is interested in posting ??? if you want instant (or near-instant) go to the IRC channels.

thanks bacon… :smiley:

If I was a rich man…

I would sponsor lots of $$$ to crack skype. Just to have it cracked :smile:


And you would have to be rich as, I feel ebay have very deep pockets and very good lawyers.

As far as codecs go its ilbc. There are a few white papers about how it works.

few things-

  1. as i recall skype can use 16khz or 32khz audio with some funky iLBC variant. Higher sampling rate = better audio usually.

  2. as for talking to people on * that depends on what codec you and they are using. In my experience using g.711 ulaw everywhere provides excellent quality (at the expense of bandwidth). On my IP system, when I talk to people on a ulaw voice path the quality is easily better than PSTN.


And you would have to be rich as, I feel ebay have very deep pockets and very good lawyers.

As far as codecs go its ilbc. There are a few white papers about how it works.[/quote]

I wouldn’t for the money. I would post the info on annon site and post code to have it work for asterisk so people can add it them selves :smile:

im with dovid. I dislike proprietary protocols and such… and the thing is if Skype opened up it would probably generate a TON of skype new accounts/use…

Personaly I have no problem with proprietary protocols, But then again I have been working in this industry for over 25 years so they are nothing new and coexist very happily . As to skype I dont use it as it has little to offer me .

And finaly as to cracking it, If people wanted to they could. But they havent as there is little point, It also wont matter if it was you who cracked it or just use the cracked version it will be you who ends up in court. Im sure they will licence it, and as it stands you can get a skype channel for asterisk at chanskype.com/ not tried it though.

I dont see how you can end up in court if you do it from the middle east and post the code on the asterisk list. Once its out there its out there :smile:

oh, by the way I must say Skype is peer-to-peer client like Kazaa…,so peers directly connected with each other when comminucating where asterisk in server based one. If u not sure run ethreal and see…how packets are going…

given it was developed by the same developers of Kazaa …

have you also seen the ports it uses to communicate. anything in regular use to get around firewall and network restrictions. and the supernode stuff is a sysadmin nightmare.

that and the licence should be enough to make anyone keep well away.

edit: i should add that i dislike eBay (the company … i still buy there if i can’t get something elsewhere). this is mostly due to the fact that i have a lifetime ban from the forums for exposing a bug that enabled how to collect usernames and email addresses with a single line of javascript.

ya, If Skype cant forward any UDP packets through ur firewall it even uses TCP right…thats y it works with most of port restricted firewalls…But u can ban the user accessing skype login server using a proxy. That is killing the root… :smiley:

Here is the main doc on how it works from a couple of years ago by columbia university.

www1.cs.columbia.edu/~library/TR … 039-04.pdf

Covers most of the basics on how it works.

oh man…i have that document too…btw thanks for infomation :smiley: