Phone unreachable after a transfer

[CedricB]

Hi everybody,

We have a problem with our phones :

- When a call is received from outside, an operator answers the call and attempts to transfer the call to an internal number. Sometimes, this transfer does not work, the recipient phone is unreachable. After that the phone does not work for 5 or 10 minutes (impossible to call this phone from anywhere). Or, if the unreachable phone makes a new call, the phone operate again just after. I precise everything was well before, this is a very strange issue and we cannot reproduce it all times.

Details if I am not clear :

0. Everything is OK.
1. 014844241XX is calling my company with the number 014844241YY.
2. 4 internal numbers are ringing (200 to 204) and the number 202 answers.
3. The 202 transfers this call to the internal number 205, but this is impossible because 205 seems unreachable (nothing happens).
4a. After that, the number 205 is unreachable between 5 or 10 minutes.
4b. After that, the number 205 is unreachable but if the number 205 tries to make a new call, it will work again.

We had a look to the network and we did not find any relevant information (errors, drops, etc), we tried in a busy hour and in a quiet hour : this is the same. Everything else with the network seems OK.

With the Wireshark capture, we see some ICMP "242 Destination unreachable (port unreachable)" and TCP Retransmission or DUP ACK, I am looking for something with that.


Do you have any ideas about that ?


Phone :
Platform : 6865i
Firmware Version 4.2.0.2023
Firmware Release Code SIP
Boot Version Boot2 1.0.0.D Jun 16 2016 01:28
Server MITEL MiVoice Office 400


Thank you and have a good day !

Cédric

 

[sarond]

Is the phone being provision by the MiVO 400?
Is it on the same network/subnet?

 

[CedricB]

Hello,

Yes, the phone is provisioned and on the same subnet/VLAN.
Do you think that could be related to the network or the MiVO 400 ?

Thanks

 

[sarond]

I'm wondering if there is some sort of timeout, like a SIP registration.

 

[CedricB]

Hello,

What I can check in your opinion about that ? Maybe something about port configuration ?

Regarding the SIP registration I have the default parameters.

Somebody told me to turn off ICMP on the router to see what will happen, I will do a test this evening I will let you know.
But if you have another idea, do not hesitate ;-D

Thank you

 

[CedricB]

Hello,

We tried yesterday and unfortunately we was not able to reproduce the transfer problem with the ICMP and without the ICMP.

However, we noticed when we have the ICMP active : 12 "ICMP destination unreachable (port unreachable)", between the both phone, then 1 or 2 "ICMP destination unreachable (port unreachable)" between the phone recipient and the Server (EIP slot 1-1).
The ICMP seems not work in any case for this transfer, but the transfer was working this time (we tried more than 10 times)

I don't know if this is an interesting information, I am still investigating.

Thanks

 

[CedricB]

Hi,

We have found something interesting I think :

Our server is configured with :
Main address : 192.168.17.10
EIP slot 1-1 : 192.168.17.11

We have reproduced a problem and we have seen some packets received or answered with 17.10 or 17.11, this looks random. We got some malformed or collision packets in the same time, so probably something is wrong with that, but at the moment I don't know why...

Still on it, thanks !

 

[CedricB]

Hi,

After the intervention of an external company on the problem, we did not found the cause. Below their description if someone has an idea ?

"At about 11:00 one of the phones stopped responding to web browsing. This phone belonged to XX who is based behind the switch 06. The issue with the phone is that whilst it responds to pings the device itself becomes unresponsive. We are not able to logon to the phone interface, pull down captures, change settings. At the same time, the phone becomes unstable when trying to make calls, change the settings, retrieve call lists, etc. Its almost as if the phone freezes.

After a few moments the phones becomes normal again. This time can vary and also, any previous changes or operations on the phone then activate. For example, if a user tries to call someone a few time whilst frozen, the phone will try and call that person. This prevents the phone from being used, whilst also locking out the recipient's phone until the call is cleared. The only way to clear the issues is to reboot the caller's phone and wait for the issues to leave the recipients phone.

We then concentrated on 3 users who were all then starting to have issues. These users are based in the recipient office and the production office (again, not on the same network switch as the phone system). After an hour were we are able to produce some captures of the phones and the issues they were having."

"This was a call from on of the users on the network. The IP address ending .11 is the EIP card which handles call resources."


Thank you for your help,

Cédric