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[mikeG]

From day one I have been trying to resolve sound quality.  During some phone calls I receive lots of static or incoming audio breaks up making conversation impossible.  Steps I took trying to resolve my problem.
1. I have switched phone providers from Cavalier to Insight (Louisville, KY area)
2. I have ran separate network runs for all of the telephones (9 runs)
3. I have installed a separate network switch for phone system only.
4. I have added a separate router with out interned to DHCP phone equipment.
5. I have kept up with all of the updates, firmware's and SPs.
Nothing has helped.  It's not all phone calls that have bad quality but a large percentage.  I do't know what to do at this point. 

[broberds]

Is it with internal calls are only calls where one party is on an outside line?

[mikeG]

With outside line calls only, we do not use system for internal calls.  I have also noticed that speaker phone quality seams to be better then the hand set.

[broberds]

A friend of mine who owns a company that does IT services as well as sells new IP Phone systems has said that the D-Link gateway's he's used have consistently had problems with voice quality.  He has told me that once I have my system up and running that if I have quality problems to talk to him about getting an Aastra gateway with which he's had no problems.

Apparently D-Link's gateways have been better with each firmware release but they still do not rival Aastra's voice quality

[bsginc]

getting an Aastra gateway with which he's had no problems.

anyone know about the interoperability between response point hardware manufacturers ?
I'm also having the same issue, its bearable but i do get complaints often about jittery voice and delay.

[lneblett]

We also seem to have the same problem. It never happens on internal calls, only external calls and even then, not consistently. Some calls are just fine while others have significant jitter. We are in the process of going through some of the adjustments to the ATA as suggested in other posts, but not sure how/what it does and seems to be more o***uessing game. If all calls were the same maybe some progress, but when some good and others bad....then what??? Frustrating to say the least as users keep complaining, but I really don't have a solution I can offer.

[PCTechie]

Gentlemen,

Please read the postings in this forum called "Static and Advanced Settings". 

There are line settings for each line on the gateway that need adjusted for each line (basically a volume adjustment).  DLink sets them to a default setting, but it may not be correct for your lines.  Each line will need tested and adjusted accordingly.  It may not even need changed that much...Once I did this it cleared up our issues by 95%...If the volume is set too high on a line it breaks up and gets garbled...to low it does the same thing.

Read the posts in that thread and see how it goes.  Let us know.

[mikeG]

I have tried changing "Static and Advanced Settings" -- NO IMPROVEMENT.

[dsiegel]

I was wondering if anyone on this thread ever tried replacing the Dlink gateways.   I am having lots of trouble with mine and would appreaciate any chance at a solution.  Not only are pstn calls poor in quality on the dlink gateways but the ones I have been wresting with are rebooting several times a day.

[dsiegel]

I found with POTS lines provided by ATT that setting the TX to -10 and the RX to -6 did help the sound quality issue.  I am still not sure that it is perfect but it did reduce the complaints quite a bit.

I had also tried changing the codecs and timing but the default (G.711 ulaw - 20ms) seems to work the best.

If anyone has tried anything else that works please post. 

[Veldud]

In our case, none of those settings help. D-Link tech. suggests us to play around with the codecs priority. We did found G.729 works best for us on 2-way call, not 3-way call. On the 3-way call, it sounds muffle and scratchy.

our current firmware (provided by DLink Network Engineer):
Phone: 1.14.28
DVGs: 1.03.01a
Base: software: 1.21.5017.0
        Platform: 1.02.163403.06.05

[dsiegel]

I wonder...

If you are on a 3 way call with all internal phones how does it sound? 

Did you change the primary codec on each phone or just on the gateway?

[dsiegel]

And on other thing...

It looks to me like you have newer firmware for your DPH-125MS's than what is available on the dLink site.  Do they tell you what is improved in the new release?

[Veldud]

I wonder...

If you are on a 3 way call with all internal phones how does it sound? 

All internal calls sound normal, even 3-way.

Did you change the primary codec on each phone or just on the gateway?

Gateways and phones. The voice cut in/out is still there, but much less noticeable.
I only changed the order of the codecs, nothing taken out. For Example: 1. G.729 2. G.711 ulaw
If I try to remove the G.711 ulaw, no calls can be made.

And on other thing...

It looks to me like you have newer firmware for your DPH-125MS's than what is available on the dLink site.  Do they tell you what is improved in the new release?

No. I didn't ask.

[dsiegel]

The issues seem to point back to gateways being the problem.  If you can have a 3 way call with internal phones and cannot when one call is being handled by the gateway then it is pretty clear where the issue is.   I wish there was another piece of hardware available to test with but I have not found one.  I notice that the firmware you are using on the gateway is also later than what is on the dLink website so it does not appear that further updates will fix the issues.

On the codecs, I had all phones and GW's set to use 729 at one point but dLink asked that I set everything back to factory default for troubleshooting so we are now back to 711 u-law.   I was under the impression that 729 accomplished the same tasks with less network traffic than 711, but honestly I don't think there is much difference in either one.  The audio quality for individual calls appears to be completely dependent on the volume settings in the gateway.  If dLink does make a new box to replace the current gateway hopefully they will include a dsp chip that can help to adjust natural volume inflections on phones calls a bit more in addition to other improvements.

Of course, I have been wrong before and could be this time and it could be that your network is dropping packets.  Can you tell me if you gateways and phones are using DHCP or static addresses?  If you are using DHCP and internal DNS what server are you using?  Do your phones and gateway appear in DNS?