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T42G - slow incoming audio - Printable Version

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T42G - slow incoming audio - stevem - 11-10-2016 02:09 AM

Hi,

I have a customer with 4 T42G phones in their office.
Their ADSL connection was poor due to bad copper lines in the area and that wont be resolved for another 2 years when fibre is installed in the area.
They are trialling an alternative broadband delvery - 4G wireless broadband - and it seems to have improved the speed and reliability of the internet.

The problem is that now the phones are having problems.
The phones ring in, but when the call is answered, there is a delay before audio arrives each time. This is around 4 seconds, but can be longer (in testing it has been utpo 40 seconds).
I have upgarded the phone to the latest firmware, changed the jitter buffer settings, forced to lowest possible Codec, but nothing has improved.

Can anyone help with why this could be occuring.??

I have attached a pcap trace.

many thanks,

Steve


RE: T42G - slow incoming audio - celito - 11-10-2016 03:09 PM

Keeping in mind that a 4G wireless broadband card has to wirelessly go back and forth from a tower, what kind of ping time is your client getting between their network and the carrier?

Higher throughput (faster speeds) doesn't mean lower latency (lower ping time). DSL has very low latency while an aircard can have very high latency. This would have the effect of faster download speeds on something like a computer, but longer delays in audio on something like voip.


RE: T42G - slow incoming audio - stevem - 11-10-2016 07:15 PM

Hi Brent, thanks for responding.

I just ran 500 pings to the service provider.
Average is 50ms, best 34ms, worst 307ms - 0% loss.

This doesn't seem too bad to me...?

Steve

(11-10-2016 03:09 PM)brentn Wrote:  Keeping in mind that a 4G wireless broadband card has to wirelessly go back and forth from a tower, what kind of ping time is your client getting between their network and the carrier?

Higher throughput (faster speeds) doesn't mean lower latency (lower ping time). DSL has very low latency while an aircard can have very high latency. This would have the effect of faster download speeds on something like a computer, but longer delays in audio on something like voip.



RE: T42G - slow incoming audio - Travis_Yealink - 11-28-2016 12:42 AM

(11-10-2016 02:09 AM)stevem Wrote:  Hi,

I have a customer with 4 T42G phones in their office.
Their ADSL connection was poor due to bad copper lines in the area and that wont be resolved for another 2 years when fibre is installed in the area.
They are trialling an alternative broadband delvery - 4G wireless broadband - and it seems to have improved the speed and reliability of the internet.

The problem is that now the phones are having problems.
The phones ring in, but when the call is answered, there is a delay before audio arrives each time. This is around 4 seconds, but can be longer (in testing it has been utpo 40 seconds).
I have upgarded the phone to the latest firmware, changed the jitter buffer settings, forced to lowest possible Codec, but nothing has improved.

Can anyone help with why this could be occuring.??

I have attached a pcap trace.

many thanks,

Steve

Hi Steve,

For this issue, did you factory reset the phone after firmware upgrading?
Suggest you test the IP direct call, this test will help us find out if the server side issue. for how to do it, please refer below FAQ:
http://support.yealink.com/faq/faqInfo?id=223

if the issue still exist, please kindly provide THREE trace files together:
a. Level 6 syslog
b. PCAP trace
c. Config.bin
You can get the guide from this link to see how to export the issue data:
http://support.yealink.com/faq/faqInfo?id=311

BR
Travis