External number shows "Unknown number" on IP phone display

[amorguettat]

Dear all,

We have an Cisco systems 2800 series.

The following "About the System" of "Cisco systems 2800 series":

About the System
Cisco Unified CallManager Express
OS Description Cisco Internetwork Operating System
Cisco IOS (tm) C2801
Cisco IOS Software C2801-SPSERVICESK9-M
Software Version 15.1(3)T3 / CME 8.5
Feature Package IP|FIREWALL|VOICE|PLUS|SSH|3DE

GUI Version 4.2.0.0 (Compatible with IOS 12.4(11)XW1)

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Copyright (c) 1986-2004 by Cisco Systems, Inc.

I getting Unknown number on display for all the incoming external calls. Display is working fine for all Internal calls.

Please see attached picture.

Waiting for your valuable response.
Best Regards,

[Mohammed Khan]

Hi amorguettat,

Can you confirm the call flow

Do you have FXO in call flow?

Regards,

Mohammed Noor

[amorguettat]

Dear Mohammed ,

Please see attached picture for our Cisco systems 2800 series.

Best Regards,

[Mohammed Khan · Accepted solution]

Hi amorguettat,

Make sure you have configured correct cptone and below config on the FXO port

voice-port x/y/z
cptone ?
caller-id enable
caller-id alerting dsp-pre-allocate
caller-id alerting ring 2
shut
no shut

Regards,

Mohammed Noor