voip call quality

shady · 5 Mar 2009 at 10:03

I'm having random problems with call quality on a voip service, mainly with USB phones. Is there a product out there can monitor the performance or highlight where the bottleneck is happening.

antijoke · 5 Mar 2009 at 10:19

What broadband service are you using?

cybergeek · 5 Mar 2009 at 10:22

Are you using Skype, SIP other? Who is your provider?
Are you using torrents or downloading a lot of files?

shady · 5 Mar 2009 at 11:29

The phones are USB but ru n on a sip protocol. Tv provide is voispeed and there are no large downloads in progress during during calls. We has a server in the I'm which connects to our isdn lines and the USB phones connect to pcs on tvlhe same network or over the Internet Ina different country, and these are the ones that are suffering from a drop in quality. We have 2mb adsl connection at the I'm end and a 4mb conn At the other. Pcs are connected to a wireles router.

bigredshark · 5 Mar 2009 at 11:45

shady said:
The phones are USB but ru n on a sip protocol. Tv provide is voispeed and there are no large downloads in progress during during calls. We has a server in the I'm which connects to our isdn lines and the USB phones connect to pcs on tvlhe same network or over the Internet Ina different country, and these are the ones that are suffering from a drop in quality. We have 2mb adsl connection at the I'm end and a 4mb conn At the other. Pcs are connected to a wireles router.

a 2mb ADSL connection with 256k upload? That could well be your problem. Depends on the codecs your using though...

shady · 5 Mar 2009 at 13:00

Sorry about the spelling, i'm on a mobile device

ci_newman · 6 Mar 2009 at 13:21

bigredshark said:
a 2mb ADSL connection with 256k upload? That could well be your problem. Depends on the codecs your using though...

That's almost certainly going to be your issue if it is only a 256k upload line! Depending on your overheads, you're probably only going to get 2 / 3 concurrent calls before maxing out the DSL line. FYI:

Code:

 Codec       BR       NEB
 G.711     64 Kbps  87.2 Kbps
 G.729      8 Kbps  31.2 Kbps
 G.723.1  6.4 Kbps  21.9 Kbps
 G.723.1  5.3 Kbps  20.8 Kbps
 G.726     32 Kbps  55.2 Kbps
 G.726     24 Kbps  47.2 Kbps
 G.728     16 Kbps  31.5 Kbps
 iLBC      15 Kbps  27.7 Kbps

[Edit] Numbers taken from http://www.voip-info.org/wiki-Bandwidth+consumption

shady · 9 Mar 2009 at 10:24

thanks, all replies were really helpful