Voice Delay Problem somtimes



The problem I’m having is that if

  • I call an extension from a phone to another extension voice come after 5 second after
  • the call is answered and then it takes 5-10 seconds for the sound to be carried over (be heard) - customers are confused and hang up or they do not hear us greet them,(Out side calling)

i have google search that voice delay comes because of jitter and packet loss
so i captured packet after enabling PBX SETTING-------> jitter setting then also packet loss showing in wireshark RTP Stream

i m not much familiar with wireshark to troubleshoot problem only i have identify from google is that packet loss problem it is
Packet capure.zip (8.8 MB)


Does the problem also arise between conversations between local phones?
first of all, it eliminates superfluous codecs.


Two things:

  1. Can you explain the number that you are dialing?
    SIP to address: sip**:917978423043**@

I am of the impression that you want to reach another extension connected to the same UCM and all are on the same local network. Should I also assume that the delay is only seen on extension to extension calls and not external calls? I am wondering why you are simply not dialing “298”.

  1. You apparently have allow unsolicited refer set in the phone. Until we understand more about how and why you simply don’t just dial the extension number, I am not sure what to recommend.


Yes between local phones


If the delay is also between local phones I would start to seriously worry


yes want to reach another extension connected to same UCM andit is on same local network … delay is for extension to extension calls and external calls also.


Sorry, but that did not answer my first question -

  1. Can you explain the number that you are dialing?
    SIP to address: sip** :917978423043 **@


Yes this number external number we are dialing and and tested on internal number also
what it is showing packet lost but i dont know for what reason


Ok, there is a communications problem in how you are explaining the issues.

You indicated - “I call an extension from a phone to another extension”, but what the trace showed is not an extension to extension call, but rather that you dialed some number other than extension 298. You ended at 298, but it was not a direct call apparently but from a REFER.

As you can see from the below:

There is no RTP stream being sent to the originating extension 200 or any device for that matter.

I am trying to understand the exact steps that were taken by extension 200 when trying to reach 298, so that I can understand the “REFER” (transfer of some type?), that is sent by extension 200 some 5 seconds after the UCM ack’ed the call. I would also like to know if the connection method by the provider is PRI given the 6510 and if not, what type?.

First, in all the extensions and trunks, determine what the provider needs to see. In your locale the standard is typically g711a and/or g729. Whatever it is that your provider wants to see, eliminate all the others from the codec settings so that only those that are needed are being used.

I really do not care about the other capture showing packet loss yet as I need to understand the setup first, but it does show that various extensions are using different codecs.


exactly, as I wrote above you have to delete all those codecs, there is an endless list of codecs, which only waste time in the “negotiation”


i dont know what is cause of delay in voice so i capture more file after restarting UCM and Jitter buffer setting enable i m not expert in wireshark so may be you can help me out .

one more thing is it possible voice delay because of cisco small business poe switch??

please download capure file from external link it is not allowing to upload big file

Capture file


to remove network doubts do so, take 2 phones and connect them directly to the UCM (thus skipping any network switch and the network itself), if the problem between the 2 phones also occurs by connecting them directly to the UCM will mean that it is a problem of settings on UCM or setting the phones themselves.
If doing so, the problem “disappears” there are network problems.

n.b.: I have already written you above 2 times to delete ALL codecs and try with only one -> PCMA/PCMU


Sorry, but I cannot help you unless you answer the questions that have been posed. I know nothing about your setup nor do I know why your are dialing what appears to be an external number to reach an internal extension, if your are using PRI or other of if your simply dial 298 if the delay is still present. Looking at the traces for the jitter buffers is pointless as there are no calls between 200 and 298 and you did not tell us what calls are the ones we should be looking at if not 200 and 298. As Damiano points out, you also did not remove the unneeded codecs that he suggested first and I as well afterwards.

If you are able to dial extension 298 directly from extension 200 without dialing an external number, then the issue is not the local network with regard to the switches. That is all I can offer at this point.

Good luck.


yes i can able to dial 298 from extension 200 without dialing external number and yes i also think issue with cisco switch


when you dial 298 from 290…is the delay still present?


yes that is main problem internnal call delay…and it will delay radomly like when i try to dial 3 to 4 times thn suddenly one time come … means randomly delay comes not everytime.


Please show a wireshark capture of the internal calling from extension to extension with the delay.


did you have to do what I wrote on it?