Cisco IP Phones on Alcatel Switch

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Cisco IP Phones on Alcatel Switch

Post by philip123 » 07 Jun 2017 23:35


One of my customers has encountered an issue, will like to seek out any opinions to solve it.

They are using Cisco IP Phone, connected via OS6450 as edge switches and OS6900 as core switches

Laptop (Cascade with IP Phone) <-> Cisco IP Phone <-> OS6450 <-> OS6900 <-> WAN <-> Cisco Call Mananger

They are experiencing the phones suddenly rebooting and get stuck in the "Configuring" stage.

The edge switches are configured with 802.1x with Clearpass, with phones as MAC authentication. It's an L2 setup on the edge and core, with a static route pointing towards the WAN gateway.

During the issue state, what we see is that the phones are in the correct VLAN assigned and that the core has learned the correct mac table. B/W Utilization seems fine, and no critical logs are showing. The thing is we suspect it's the call manager having the issue, however, the CCM logs point back to the network issue, where the phone is unable to reach the call manager and thus timeout happened.

To resolve the problem the users had to unplug and replug the phones again, which is very interruptive as it happens randomly daily.

Any idea on how to go about finding the root cause?

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Re: Cisco IP Phones on Alcatel Switch

Post by dryhouse » 06 Mar 2018 06:35


In our customer happen something similar.

A4018 SIP mode and swichts Cisco with 802.1x and ClearPass. The phones loss signaling with the server and reboot, but port doesn´t shutdown . The swicht doesn´t detect any shutdown and not send re-authenticafication to ClearPass so there is no traffic.Port is blocked

may the force be with you....

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