Call Delay gets worse and worse with length of call.

[Ralph]

Good afternoon,

I am having a rather odd problem with delay.

Calls start out ok with a delay of less then 1/2 second.
The delay begins getting worse and worse as the call continues till after 5 minutes of conversation you have a 6 second delay and after 10 minutes of conversation you have an 11 second delay. The delay is both directions.

It goes like this:

Start of call: Caller1<---less than 1/2 second delay--->Caller2
5 minutes later: Caller1<---6 second delay--->Caller2
10 minutes later: Caller2<---11 second delay--->Caller2

Needless to say this is a major problem for us. Really hasn't been an issue until now most likely because we just switched to VoIP and hadn't made any lengthy calls until now.

I have implemented QOS and it hasn't seemed to make any difference.

Logs from one of the calls are below:

11:54:22.805 StratLink:nHangUp [CM104001] Call(1): Ext.201 hung up call; cause: BYE; from IP:XXX.XXX.XXX.XXX
11:42:29.993 CallLegImpl:nConnected [CM103001] Call(1): Created audio channel for Ln:10001@BroadVoice 2 (147.135.12.247:19448) with Media Server (XXX.XXX.XXX.XXX:9000)
11:42:29.983 StratInOut:nConnected [CM104005] Call(1): Setup completed for call from Ext.201 to Ln:10001@BroadVoice 2
11:42:29.983 CallLegImpl:nConnected [CM103001] Call(1): Created audio channel for Ext.201 (XXX.XXX.XXX.XXX:2230) with Media Server (XXX.XXX.XXX.XXX:7000)
11:42:23.104 CallConf:nProvisional [CM103003] Call(1): Ln:10001@BroadVoice 2 is ringing
11:42:18.802 CallConf:nIncoming [CM103002] Call(1): Incoming call from 201 (Ext.201) to sip:[email protected]

Any help is greatly appreciated.

Thanks again

 

[Ralph]

Wierder still

I have done a bit of testing.

If I establish a call and then have the call remain active for several minutes with normal or little traffic the delay gets progressively worse.

If I establish a call and then put it on hold with music on hold playing the delay does not get any worse when I resume it several minutes later.

I also noticed that on a couple occassions when a call that has had no traffic had conversation resume the delay got progressively better with increased voice traffic.

Does 3CX put calls into hibernation or lower their priority somehow if there is very little or no voice traffic? If so how do I disable this feature?

Do VoIP providers do this?

Thanks again

 

[RobLloyd]

Do your phones have silence suppression turned on? Some of them can tell when they hear nothing do not push out any data packets to help keep the calls static free (or something to that effect). Maybe that's what's happening and the delay is caused by it turning on and off.

Does this happen with all your phones and a softphone?

Just my .02 worth.....

 

[SY]

It is like a "theory of relativity" - time is different for different (VoIP) systems .

Currently MediaServer don't like system where time is faster then on PBX host. (in theory of relativity has speed less than 3CX PBX . Next version will be more tolerant even in this case because we investigate relativity more careful ).

Do you run PBX on stand alone host or use Virtual Machine?

 

[Ralph]

Problem solved !!! and then some !!!

Good morning,

I have been doing some more testing and harassment of tech support at a variety of our providers :lol:

I was going through the 3CX management console for the millionth time when I read the following under "Edit VoIP Provider":

Specify additional options. More > Enable the "PBX delivers Audio" setting to use the Media Server to deliver Audio. This option is recommended to resolve firewall and transfer issues.

It then occurred to me that we have no need to resolve firewall or transfer issues since we use a static public IP and that the delay we were experiencing might be due to additional steps or spooling on the PBX as it delivers audio in addition to everything else.

So I unchecked the "PBX delivers audio" option for all our lines and voila our call quality jumped 100% (no static at all) and delay completely disappeared

I have been testing this on a variety of calls ranging in length from 20 - 70 minutes so far and the excellent call quality and absence of delay are consistent.

Take care,

 

[SY]

Re: Problem solved !!! and then some !!!

Good morning,

I have been doing some more testing and harassment of tech support at a variety of our providers :lol:

I was going through the 3CX management console for the millionth time when I read the following under "Edit VoIP Provider":

Specify additional options. More > Enable the "PBX delivers Audio" setting to use the Media Server to deliver Audio. This option is recommended to resolve firewall and transfer issues.

It then occurred to me that we have no need to resolve firewall or transfer issues since we use a static public IP and that the delay we were experiencing might be due to additional steps or spooling on the PBX as it delivers audio in addition to everything else.

So I unchecked the "PBX delivers audio" option for all our lines and voila our call quality jumped 100% (no static at all) and delay completely disappeared

I have been testing this on a variety of calls ranging in length from 20 - 70 minutes so far and the excellent call quality and absence of delay are consistent.

Take care,

Good evening
Yes it is a case! As far as your have good environment, could you please help me to perform some tests ?

Thanks

 

[Ralph]

Hi Sy

Good afternoon Sy,

I am running 3CX (Free Edition) on a Stand Alone, Windows Server 2003 virtual server. The Virtual Server has 1 Gig of RAM allocated to it and a 40 Gig virtual hard drive.

It also has its own static public IP.

So far calls up to 1hour and 30 minutes in length have been fine since implementing the fix above.

 

[Ralph]

3 Hours and all is well

Well I finished a 3 hour conference call (Tech Support) :roll:

The system worked great, no static, no delay.

So far so good

 

[liberars]

Re: Problem solved !!! and then some !!!

Good morning,

I have been doing some more testing and harassment of tech support at a variety of our providers :lol:

I was going through the 3CX management console for the millionth time when I read the following under "Edit VoIP Provider":

Specify additional options. More > Enable the "PBX delivers Audio" setting to use the Media Server to deliver Audio. This option is recommended to resolve firewall and transfer issues.

It then occurred to me that we have no need to resolve firewall or transfer issues since we use a static public IP and that the delay we were experiencing might be due to additional steps or spooling on the PBX as it delivers audio in addition to everything else.

So I unchecked the "PBX delivers audio" option for all our lines and voila our call quality jumped 100% (no static at all) and delay completely disappeared

I have been testing this on a variety of calls ranging in length from 20 - 70 minutes so far and the excellent call quality and absence of delay are consistent.

Take care,

Good evening
Yes it is a case! As far as your have good environment, could you please help me to perform some tests ?

Thanks

I have had same problem, and resolved with the same method. Best regards

 

[liberars]

Can 3cx PBX interacted with external scripts

Hi,
I' m Developer,
I would have the necessity to execute script on call in.
Currently I make this from my client voip (start exe application on DTMF tone, record call in, etc.)
In the future can 3cx PBX interacted with external scripts?

Best regard

Gianfranco

 

[SY]

So... Do you use VMWare or (other)"virtual machine" software to start PBX or not?

Thanks

 

[liberars]

Hi, I not use VMware.
My configuration is:
PIV 3000
2Gb ram
Hd SATA
PBX run on the other HD.

I've Test PBX also on the
PIII 1000
512 Mb ram
HD 40 IDE

Same problem, resolved in the same way.

Regards

Gianfranco

 

[liberars]

Hi, I not use VMware.
My configuration is:
PIV 3000
2Gb ram
Hd SATA
PBX run on the other HD.

I've Test PBX also on the
PIII 1000
512 Mb ram
HD 40 IDE

Same problem, resolved in the same way.

Regards

Gianfranco

S.O. XP pro

 

[SY]

Hi, I not use VMware.
My configuration is:
PIV 3000
2Gb ram
Hd SATA
PBX run on the other HD.

I've Test PBX also on the
PIII 1000
512 Mb ram
HD 40 IDE

Same problem, resolved in the same way.

Regards

Gianfranco

Please specify maximum delay you reached and for what time.

Thanks

 

[liberars]

Hi, I not use VMware.
My configuration is:
PIV 3000
2Gb ram
Hd SATA
PBX run on the other HD.

I've Test PBX also on the
PIII 1000
512 Mb ram
HD 40 IDE

Same problem, resolved in the same way.

Regards

Gianfranco

Please specify maximum delay you reached and for what time.

Thanks

- call in

- first minute of conversation no delay

- Between first and second minute of conversation 2 or 3 second of delay

- After the third minute of conversation the delay it remains stable 5 or 7 second

Without the flag the delay less than 1 second

P.S.
The test has been made a lot accurately more times
The delay is in in and out

 

[SY]

Gianfranco,

Thanks a lot for your information.
We are investigating reasons of this situation.

Anybody has a comments?

Thanks

 

[liberars]

Hi, SY
You can explain me exactly what makes the flag PBX delivers audio?

Regards
Gianfranco

 

[SY]

RTP proxy

 

[liberars]

It seems strange that the audio is succeeded to feel

 

[liberars]

Hi, I am making of the tests the PBX.
I have noticed that if a client is closed without to carry out the logoff, the call remains hung and remains like bottom of the called new.
Is normal?

Regards
Gianfranco