Comware

I have about 400 Mitel 6900 series VoIP phones across 6 different buildings on our campus. Our switches are set up to use LLDP-MED to tag the Voice VLAN when a phone boots up.  All is working fine, but occasionally we have an overnight "event", and when we return in the morning about 10% of the phones in each building are now connected to the untagged VLAN of their port instead of the tagged Voice VLAN.  The offending phones are connected to different switches in the same building, and across all 6 buildings.  When we power cycle the phones, they correctly renegotiate LLDP-MED and join the Voice VLAN as normal.  Looking at the uptime, we can confirm that the switches did not power cycle.  Its as if something caused the LLDP-MED to renegotiate but fail, and the he phone now assume there is no tagged Voice VLAN and so they just join the untagged VLAN.  Any ideas what might be triggering this?

Hello joes@digitalbackoffice.com,

You may start by checking if the issue appears when the phone DHCP lease exires and check if this is the problem.
You may check if there is port security and if the phones are losing their session on port.
There are no much details such as what are the switches, their software version and configuration of the ports. But since it may need a lot more details and possibly capture of the traffic from the phone you may need to open a ticket with TAC.

Hope this helps!

EDIT: I would check also Mitel if there could be any firmware update needed

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-Alex-
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Original Message:
Sent: Oct 26, 2022 02:37 PM
From: Joseph Sauer
Subject: VoIP Phones Randomly Drop Off Voice VLAN

I have about 400 Mitel 6900 series VoIP phones across 6 different buildings on our campus. Our switches are set up to use LLDP-MED to tag the Voice VLAN when a phone boots up.  All is working fine, but occasionally we have an overnight "event", and when we return in the morning about 10% of the phones in each building are now connected to the untagged VLAN of their port instead of the tagged Voice VLAN.  The offending phones are connected to different switches in the same building, and across all 6 buildings.  When we power cycle the phones, they correctly renegotiate LLDP-MED and join the Voice VLAN as normal.  Looking at the uptime, we can confirm that the switches did not power cycle.  Its as if something caused the LLDP-MED to renegotiate but fail, and the he phone now assume there is no tagged Voice VLAN and so they just join the untagged VLAN.  Any ideas what might be triggering this?

Hi, i have no experience of exactly this scenario but we have a huge amount of dumb IoT that in different scenarios will not transmit and frame. They are always pingable and if you point them constantly then all is well. If there is an event that causes a break in this then they will drop to the unauth vlan. When here they never transmit so remain in jail.

Unlikely your scenario but worth checking if the event you get is where the phone goes to sleep and does the same. One test would be to set up something that pinged all phones in one building. Or check interface stats while on the failed state.

In our case we arp scan the unauth vlan for every auth subnet once every 10 mins. This brings all devices back because they transmit an therefore get MAC authed.
Original Message:
Sent: Oct 26, 2022 02:37 PM
From: Joseph Sauer
Subject: VoIP Phones Randomly Drop Off Voice VLAN

I have about 400 Mitel 6900 series VoIP phones across 6 different buildings on our campus. Our switches are set up to use LLDP-MED to tag the Voice VLAN when a phone boots up.  All is working fine, but occasionally we have an overnight "event", and when we return in the morning about 10% of the phones in each building are now connected to the untagged VLAN of their port instead of the tagged Voice VLAN.  The offending phones are connected to different switches in the same building, and across all 6 buildings.  When we power cycle the phones, they correctly renegotiate LLDP-MED and join the Voice VLAN as normal.  Looking at the uptime, we can confirm that the switches did not power cycle.  Its as if something caused the LLDP-MED to renegotiate but fail, and the he phone now assume there is no tagged Voice VLAN and so they just join the untagged VLAN.  Any ideas what might be triggering this?