Mitel IP phone screens blank with backlight on

[tsame]

Hello. I am administering a Mitel 3300 ICP. On some days, the screens of some of the Mitel IP phones, on the network, go blank with the backlight on (i.e. they are powered on and dialing these extensions from a working IP phone shows the "OUT OF SERVICE" message. I checked the computers which are connected to these affected IP phones and the network connection of these computers are working fine e.g. they can access the internet.

I have also noticed that the switches, which the affected IP phones connect to, show solid LEDs when this problem is experienced. This is temporarily fixed by restarting the switches, where the LEDs start flashing again and the screens of the affected IP phones are not blank anymore (they correctly show the "LOGGED OUT" message for ACD extensions and the date and time for non ACD extensions).

What could be causing some of the IP phones' screens to go blank? I would like to find the source of the problem so that it can be permanently fixed.

 

[Wishforall]

Hi tsame,

There could be a number of problem. Please give me some more information.

Software level?
Type of phones?
Network setup?
Static or DHCP?
Model of switches?
Are the switches managed?

Regards,
Wishforall.

 

[tsame]

Software level?

Mitel 3300 ICP is running release level 7.0 SP1.​

Type of phones?

[ul]
[li]Mitel 5312 IP phones[/li]
[li]Mitel 5224 IP phones[/li]
[li]Mitel 5212 IP phones[/li]
[/ul]

Network setup?

Two VLANs are being used: VLAN 1 for data and VLAN 2 for voice. VLAN 2 voice traffic is prioritized over VLAN 1 data traffic.
Spanning tree protocol and loop protect are configured on all switches to prevent layer 2 loops.​

Static or DHCP?

VLAN 1 (data):
[ul]
[li]Computers receive automatic settings via a DHCP server.[/li]
[li]Servers and a few end user computers use static settings.[/li]
[/ul]

VLAN 2 (voice) IP phones receive automatic settings via the Mitel 3300 ICP DHCP server.
​

Model of switches?
[ul]
[li]HP J9625A[/li]
[li]HP ProCurve J9087A[/li]
[li]HP J9089A[/li]
[li]HP J9627A[/li]
[li]HP J9145A[/li]
[/ul]

Are the switches managed?

Yes, all switches are managed.​

 

[wireman50]

Possibly PoE problems as in not the power budget of the switch has been exceeded. This can produce some odd faults like this. I even had one where a PoE WAP was plugged in and that consumed most of the power leaving phones in various states of disarray....

 

[VinceWhirlwind]

Does it affect phones on *all* those switches, or just some of them?

 

[tsame]

Possibly PoE problems as in not the power budget of the switch has been exceeded. This can produce some odd faults like this. I even had one where a PoE WAP was plugged in and that consumed most of the power leaving phones in various states of disarray....

During the time that the phone screens were blank, I checked the POE power utilization of each switch via the command line. It turned out the switches had more than enough power remaining (the switch with the maximum power remaining was 393 W and the switch with the minimum power remaining was 310 W). I also monitored the POE consumption of 3 switch ports where the connected phones had a blank screen, and the power remaining on the 3 switch ports were: 14.2 W, 13.9 W and 14.3 W. So it seems that the problem is not related to POE issues.​

Does it affect phones on *all* those switches, or just some of them?

It affects all switches, but only some phones are affected. The interesting thing is that whenever the blank phone screen problem occurs, the same phones are always affected.​

 

[wireman50]

Possibly faulty phones? try replacing one to see if the problem still occurs.

Solid lights on keys usually indicate that it has lost contact with the 3300 or has started a reboot sequence that has failed (borne out to some extent by your restart of switch port curing problem). Have you tried rebooting the phone to do the same?



How many phones on the system

3300 type, system software level would maybe help along with phone type and level of software on an unafected phone and an affected phone.

 

[TLDuk]

I know this is an old thread but i had this same problem today, with some wireshark traces i found 3 mac addresses on the network generating ipv6 multicast storms, after some research links below, the customer had dell optiplex PCs with the same network adapter listed in these articles, after physically turned off the offending PCs the phones booted right up and are now working ok.

http://packetpushers.net/good-nics-bad-things-blast-ipv6-multicast-listener-discovery-queries/

https://communities.intel.com/thread/70393

Looks like these Dell PCs with a particular network adapter need the bios and network drivers updating.


If its not broke tweak it..

 

[Billz66]

yes we also had an issue with a customer rolling out new Dell PC's , they were causing broadcast storms ,we chased it with Mitel for weeks beforethey fessed up that the issue only started when the pc rollout began.
once they disbaled IPv6 and updated the NIC drivers the problem went away

If I never did anything I'd never done before , I'd never do anything.....