QUESTION Outgoing voice garbled.

[Kimberly]

Kit: Linksys PAP2 ata, USRobotics 5461 router flashed with dd-wrt, RCA DCMA 425 modem. PIAF3 with Incredible PBX 11. ISP is EarthLink through TimeWarner lines; down is up to 15 megs, up is up to 1 meg. As you can see, the hardware is old.

I had this problem in the past with the same hardware. I thought it was the PBX but even with a new box and installation the problem exists. Therefore I am inclined to believe it is the hardware or related to my ISP.

Calls often start off fine with my outgoing voice fine. Very rare my outgoing voice is garble on first making the call. I have no trouble with the incoming voice. Sometimes I can talk for very long periods before my outgoing voice is garbled and other times it is only after a short period. At times I can hear the line go completely silent and then everything is back to normal. Other times the only solution is to disconnect and redial. I have tested without any other computer on the network and it made no difference; it is not some other computer using up the available bandwidth. It happens even when someone dials my DID number directly. It happens on a Google call both in and out.

I can not really afford to just start replacing hardware but would start replacing hardware if I knew a likely source. Are there some diagnostics I can perform to help track down the issue? I have been told on an earlier forum topic dealing with this issue that 1 meg up was enough bandwidth for a VoIP call.

 

[gkuch]

You could try QOS in ddwrt on your router. 1 meg up can work as long as long as no other traffic is eating up your bandwidth. IIRC Google Voice requires usage of 100Kbps bandwidth both ways.

 

[Kimberly]

Exactly, which is why I disconnected everything except the ata, router, and PBX box from the network. There was no way anything else except those devices were using any bandwidth.

 

[randy7376]

Kimberly

Here's one thing you may not have thought of, yet.

If I'm remembering this correctly, the PAP2's Ethernet port runs at 10Mbps/half duplex with no way to change it. If you have a way of checking this, try to verify the port the PAP2 device is connected to is not configured for full-duplex, either manually-configured or auto-detected.

A duplex mismatch could cause problems with voice as packets are dropped due to the mismatch.

 

[Kimberly]

The port was set to auto-negotiate so I set it to half-duplex just to make sure that it did not try to negotiate to full-duplex.

 

[Kimberly]

I will test and see if that was the issue.

 

[Kimberly]

I set both the port and the ip address to Exempt on OoS and I set the port to half duplex and still having problems. I have asked about the problem to those that I speak with and one said it becomes a crackling noise. One said it was like a tick noise. One said garbled voice. I can often wait a bit and it will go away. What could be causing this issue?

 

[atsak]

ISP congestion. It's very rare, but I've seen it once before.

 

[Jake]

I'd try to isolate the network problem. Use a VoIP connection test like this http://myspeed.visualware.com/index.php

Then remove the router and test. Also, if possible try a different modem.

 

[Kimberly]

I got a new router and I have the same problem. I have the PBX connected to the router and the ATA is connected to the router. Probably not the router. I call and often after one word they tell me that they can not hear me but I hear them without any problem. Could it be the wireless phones that are connected to the ATA? I get the same on all four, two sets with two phones each. I have another ATA but it is not a standard ATA so not sure I can get it working; also have an old SunRocket ATA from after their crash and burn.

Suggestions?

 

[tbrummell]

If you suspect the cordless system, try with a hardwired phone.

Did you do the speed test mentioned above? This really sounds like a ISP/upload bandwidth problem.

 

[Kimberly]

If you suspect the cordless system, try with a hardwired phone.

Did you do the speed test mentioned above? This really sounds like a ISP/upload bandwidth problem.

Results:

Test Type: Voice over IP
Downstream Jitter: 1.2 ms
Downstream Loss: 0 %
Downstream Packet Order: 100 %
Upstream Jitter: 1.4 ms
Upstream Loss: 0 %
Upstream Packet Order: 100.0 %
Packet Discards: 0 %
MOS Score: 4.2

 

[MGD4me]

Test Type: Voice over IP
Downstream Jitter: 1.2 ms
Downstream Loss: 0 %
Downstream Packet Order: 100 %
Upstream Jitter: 1.4 ms
Upstream Loss: 0 %
Upstream Packet Order: 100.0 %
Packet Discards: 0 %
MOS Score: 4.2

Hmmm... looks like your network is just fine!! An MOS score of 4.2 is really decent, and look at the packet loss - zero!

Your focus should now be internal. BTW, did you eliminate the cordless phones from the equation?

 

[Kimberly]

I dug out the old SunRocket AC-211 and configured it. Same issue; sometimes the calls will be fine for 20 minutes or so. I thought at first that it was the ATA but then it started doing the same with the AC-211, the caller on the other end could not hear me. Redailing will work for a few minutes and sometimes I can call and just after a few seconds they can not hear me. So, it appears it is not the ATA. I don't understand why it would be the phones; why would I be able to hear the other caller and they not hear me because of the phones?

I am wondering if it is my ISP, Time Warner offers VoIP services at high prices; maybe they are blocking SIP packets at times, or at least the outbound sip packets. Any idea on this?

Could it be the codec? Which codec should I use, I am using G711.

 

[Twilight Sparkle]

im having same issue with sound quality all choppy. but its only INCOMING AUDIO, people over phone say they can hear me fine but i cant hear them fine.

but when i check the recordings of the call both IN & OUT, audio sounds wonderful. so it might be the the codec or something

im also not using any SIP devices just routing the call to external to cell phone xxxxxxxxxx# under follow me.

 

[MGD4me]

Same issue; sometimes the calls will be fine for 20 minutes or so.

That's the really weird part. Works fine for 20 minutes, and then aliens take over! Hmmm...

Well then, that would most likely rule out the ATA, but you didn't confirm that the cordless phone is out of the loop. Could it be that your cordless phone is running low on battery after 20 minutes, or you were walking around and found a dead spot. Also, if the phone is a 2.4 GHz cordless model, it could be suffering from , or causing, interfence with your WiFi. And finally, any nearby microwave oven certainly can, and does, play havoc on the 2.4 GHz band. Just things to ponder.

 

[BeerCan]

Just for info can you run

ip -s link

at you pbx's command line to see if any errors pop out?

 

[Twilight Sparkle]

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
RX: bytes packets errors dropped overrun mcast
3450131 50910 0 0 0 0
TX: bytes packets errors dropped carrier collsns
3450131 50910 0 0 0 0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
link/ether 04:01:2f:13:c0:01 brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped overrun mcast
11578737 42621 0 0 0 0
TX: bytes packets errors dropped carrier collsns
13391124 38552 0 0 0 0