Phones lose configuration

[Andre Castro]

Dear friends,

We have a customer with a newly installed site where phones from time to time lose their registration.

They get stuck in the "Registering" state seen on their screens and only can get back working by manually resetting its configurations.

The CUCM runs in Mixed Mode, version 10.5.2.

Any suggestion is appreciated.

Thank you!

[Nithin Eluvathingal]

What exactly you mean by loosing phone configurations. The phones are DUMP devices and they pull configuration from CUCM. What you mean by manually resetting the phone configurations ?

Could you kindly share the phone status messages.  Is there a firewall in between ?

2.12.0.0

[Andre Castro]

Hi Nithin

I got the proper info from the customer and have edited the topic.

The phones acutally get stuck and cannot register back, unless they have their config reset, e.g. erase the certificates and network properties.

Most likely there is firewalls in between, but I guess it would not explain the current resolution to the problem - temporarily, because they get back losing their registration from time to time.

[Nithin Eluvathingal · Accepted solution]

If you have firewall in between you must disable the Sip inspection on firewall for the ip phone traffic.

Instead of erasing the certificates and network properties, see the status messages on the phone and collect events logs from CUCM.

2.12.0.0

[Andre Castro]

Hi Nitin

Just a heads up as we solved the issue indeed by disabling SCCP inspection in their firewall. Some older phones can indeed be affected by this feature.

We could confirm it was being rejected, without a clear reason:

15824518.001 |14:21:12.388 |AppInfo  |StationD:    (0055533) registrationError sent StationOutputRegisterReject 

15824519.000 |14:21:12.390 |AppInfo  |-->RISCMAccess::DeviceTransientConnection(...)

15824520.000 |14:21:12.390 |AppInfo  |Device Transient deviceName : SEP2C3ECF7B0BE0, IPAddress : 10.9.27.73, IPv6Address : not shown, IPv4Attribute :3, IPv6Attribute :0, Protocol : 1

15824521.000 |14:21:12.390 |AppInfo  |DebugMsg deviceName : SEP2C3ECF7B0BE0, DeviceType : 495, risClass: 1

15824522.000 |14:21:12.390 |AppInfo  |<--RISCMAccess::DeviceTransientConnection(...)

15824518.002 |14:21:12.391 |AppInfo  |EndPointTransientConnection - An endpoint attempted to register but did not complete registration Connecting Port:2000 Device name:SEP2C3ECF7B0BE0 Device IP address:10.9.27.73 Device type:495 Reason Code:27 Protocol:SCCP Device MAC address:2C3ECF7B0BE0 IPAddressAttributes:3 LastSignalReceived:StationResponseTimerType StationState:wait_capabilities App ID:Cisco CallManager Cluster ID:CCMP-New-Cluster Node ID:CUCMSUB1

15818620.004 |14:14:46.995 |AppInfo  |StationD:    (0055530) RegisterReject text=''.

After some research we found some posts here in the cisco forums matching your suspection. They have a Juniper firewall and it exactly matched the issue. We then disabled SCCP ALG and it started working again.

Thank you!