sundance-communications.com/forum Forums TDM Business Telephone Systems Toshiba Telephones & Systems Remote IP phone users sound "under water"

Rick,

You said that on your remote IP phones you're using G711 as the primary codec. I'd go with G729A for the primary and no secondary. Select voice packet table 2. It's just a lighter codec for use over an internet connection. Unless of course, you've got some kind of crazy fast pipe on both ends. I also agree with TardianTechTexas..we don't even have Diffserv enabled at all where I'm at. Try turning it off.

Do yourself a favour and check the firmware version of the IPU card.
Also, which card is it? BIPU, LIPU, or MIPU?
Also upgrade the firmware on the sets.
Also download pingplotter. Run it for a while when you are having problems. It will show you which router hop is being the bad boy (saved my butt a bunch of times).
I had an LIPU that was causing me grief, I thought it was internet related, ran pingplotter, connection pretty good, upgraded the firmware and presto, problem gone!

Dave

LIPU_02_03D

Thanks for everyone's help. I have disabled diffserv, changed the phones to G729A and none for secondary on the phones and packet table 2 for the phones. I'll see tomorrow how people respond on the other end of the calls.

Canuckvoip, may be a little too much for me to upgrade firmware. We had the system installed 9/07 and in 8/08, the vendor installed the latest lipu card and software, I believe. I don't want to mess with that. We also had Toshiba involved. They blamed it on the internet just like our vendor.

I am deffinately going to try pingplotter, at least the freeware version. I love having a large arsenal of tools. Most are based on some type of ping or traceroute.

It is very common for Toshiba and vendors to say it is the connection. In most cases that is where the problem is at. Sometimes the internet connect just won't support a VoIP calls because of the delays or jitter.

Packet loss of 25% is pretty bad. There is definately a problem there. Sometimes I wll open another window and ping google.com as a baseline to see if the connection problem is closest to the side I am on. You can also ping the remote gateway. Since the system is on it's own internet it sould not be a problem with data traffic fighting for internet, unless you are downloading windows updates at the phone side while trying to talk.

Sometimes updating the firmware will help. The latest LIPU firmaware is 02_05D. It may be a bit much for the end user to update the firmware. That is why it is recommended for a Toshiba dealer to do it. If things go bad then they can call tech supoprt, while you can not.

I am a little puzzled about your Toshiba guy not wanting to disable Difserv. In your setup I see no benefit. If the devices on the network do not support QOS, the header is usually ignored, but there are rare occations where it can cause problems.

This type of troubleshooting is never easy.

So, after 2 years of awful voice quality on our phones, so far so good today and ping to phone has been 20-30ms.

Yesterday's changes include: dedicated cable modem (5/800K) for phones system, disable diffserv and ip phones get - packet table 2, g729a codec and none for secondary codec.

Fingers crossed for future success.

Thanks to all, so far.

What do g711 and g729a represent and what are the differences?

Compression ratio's. g711 is a higher compression,uses more bandwidth and usually gives better voice quality. g729 is a lower compression, uses less bandwidth and in some cases will provide poorer voice quality.

These represent compression levels. G711 requires a lot more bandwidth than G729. If you have the bandwidth available, the using G711 is preferred since there is less compression, thus less room for errors. G729 compresses the data packets more, requiring much less bandwidth per call. If the connection isn't ideal, there is the risk of unsatisfactory voice transmission when using G729.

Crossing paths again with replies. Sorry about that.