Voice Quality issue - Question to PCAP

[DanH]

Hi there,

I do have a problem with voice quality on a T-46G on a remote location.
I figured I could do a PCAP trace and then analyze that with Wireshark.
Unfortunately, the trace seems to be limited in size. I only get about the last 15 seconds of a call.
Is there a way to increase the PCAP buffer so that I can trace a full call with setup and hangup? I need about 2 minutes talking time to catch that voice quality issues.
I do not have any other possibility to make a trace onsite, unfortunately.
(kind of miss a snom phone with which that would not be an issue... PCAP buffer is much bigger there).

Thanks
Dan

[Yealink Support]

Hi DanH,


Sorry. It is limitted by the memory for about 500K in the PCAP buffer.

Do you get a possibility to make trace in the T46G with wireshark? Just need to connect a PC to the phone and runing a wireshark to trace calls.

[zs6rsw]

I assume that the same applies to the Yealink T42G, on which I'm having the same issue and is what brought me to this topic. Having a 500k buffer is not much use, as it doesn't really enable serious fault finding. This particularly if the problem is on a remote phone which one cannot physically get to. Is there no possibility of being able to increase the buffer size?

[Coco_Yealink]

Hi all,

It is confined by phone memory.So it may be impossible to increase the PCAP buffer.
But you can try another method to span the trace to your PC.
1.Install the Wireshark on your PC.
1.Connect the cable of PC to the PC port which is on the back of IP phones
2.Enable the Span to PC ,which path is:Network--Advanced--Span to PC
3.Run the wireshark and then reproduce your issue.
4.After you reproducing your issue,stop the wireshark.

Thx

[DanH]

Attaching a PC on the phone's switch port ist the most pragmatic way to do this, I understand that. Yet, if you are not onsite and the phone in question is 1h by car away, that is not really a good solution.

Perhaps the folks from Yealink could introduce some kind of "remote PCAP"?

For example, if I need to do a remote capture on a linux box and display in Wireshark on my machine, I would do something like this:
ssh someuser@192.168.1.50 sudo tcpdump -iany -U -s0 -w - 'not port 22' | wireshark-gtk -k -i -

Would be nice if yealink phones would allow something similar. Of course those phones might not (yet) have tcpdump installed and make it available via ssh pipe.. On the other hand, why not make the PCAP output available as a stream on a port, instead just write to a local file?

Another way is shown on AVM Routers. When I do a PCAP trace there (i.e. http://fritz.box/html/capture.html), the file is directly written to the local disk of the machine I am connecting from with the browser. So, no disk space is used on the router. I guess that might be even more simple to program into the phone firmware..

Dan

[justingoldberg]

There is an enhanced capture that begins downloading the file straight from the disk to thecomputer connected to it's gui. So theoretically your could allow your ip and port forward through the firewall into the phones web interface to do this, but not all models or former supports the enhanced capture.
I'm personally trying to read this pcap in real-time using the Linux she'll tools and pipe it to tshark to decide in real-time. What too should I use? I basically need to tail the binary file.

[DanH]

(10-12-2019 12:06 PM)justingoldberg Wrote:  There is an enhanced capture that begins downloading the file straight from the disk to thecomputer connected to it's gui.

Interesting. Which yealink phones do support that?

(10-12-2019 12:06 PM)justingoldberg Wrote:  I'm personally trying to read this pcap in real-time using the Linux she'll tools and pipe it to tshark to decide in real-time. What too should I use? I basically need to tail the binary file.

Not sure if I understand you. Do you say that yealink phones have ssh access?

We are talking here about the PCAP trace feature of yealink phones....

Dan