SIP-T21P_E2 Issue

[ajerez]

Hello support;

We have installed several SIP-T21P_E2 with the latest firmware 52.81.0.15

When we monitore the client traffic we are facing the next issue:

Randomly the phone rejects the call without even ring, if you search in the missed calls menu for example the call appears as a missed call

In the asterisk log we have the following message:
Got SIP response 486 "Busy Here" back from 192.168.100.74

It's look like the phone itself reject the call, I enclose the SIP-T21P_E2.pcap file which is a trace get directly form our server, in this file filtering with "VOIP CALLS" you can see a REJECT message

I enclose too two more files:
the 52.81.0.15_9_36_52.pcap file which is generated with the phone pcap utility
the 001565a1c9f5-sys.log.txt file which is the syslog phone file, in that you car filter using the callerid phone number "23367954"

We are 100 % sure that the agent is not rejecting the call on purpose because, as the phones gets the configuration form provisioning all the phones has all the DND options disabled

We have been working a lot with Yealink phones specially with T20 P models and as long as we know this scenario hasn't been reported

This issue causes that agents complains because lot of missed calls that's actually didn't ring at all

If there any thing else that we can send to debug this issue please inform

Thanks in advance
Best Regards

[Karl_Yealink]

Please confirm do you enable DND or Forward feature?
Would you please also export the config.bin files when the problem happen, we can check configuration from this file.

1. How many phones have this problem?
2. How often the problem will happen?

[Alvaro]

I enclose a config.bin file

Answering mentioned points

Please confirm do you enable DND or Forward feature?
R: DNS and Forward feature are both disabled by provisioning


1. How many phones have this problem?
R: More than 10
2. How often the problem will happen?
R: Every day but randomly

[Alvaro]

Hello support

Any news about this issue ?

Thanks in advance

[Karl_Yealink]

We find you disable the call waiting feature.
So when you during a call, and there is an new incoming call.
The phone will reject the incoming call. Please try to enable call waiting feature then test again.

[Alvaro]

Hello

Thanks for you respond

The phones are in a call center environment so they always receive one call at a time as the are ina call center queue
When the REJECT message is shown there is no other call established

[Alvaro]

Hello support

Any news about this issue ?
Could you find something in the provided logs and traces ?

Thanks in advance

[Karl_Yealink]

(12-21-2016 12:16 PM)Alvaro Wrote:  Hello support

Any news about this issue ?
Could you find something in the provided logs and traces ?

Thanks in advance

Do you enable the call waiting feature then test again?

[Alvaro]

Hello,

The thing is that the call waiting, as they are in a call center environment it is not in use
Besides this call rejecting took place while the phone is available, not during a call

[Karl_Yealink]

(12-22-2016 12:11 PM)Alvaro Wrote:  Hello,

The thing is that the call waiting, as they are in a call center environment it is not in use
Besides this call rejecting took place while the phone is available, not during a call

The new incoming calls will be reject cause the phone don't enable the call waiting feature during the phones in calling.

That's the problem, if you don't want the phone reject the incoming calls, one way is enable the call waiting, another way is the call center server won't arrange new call for the phones which still in calling.

Normally, the call center will arrange new calls automatic and won't arrange new calls for the phones still in calling.