SNR calls on the remote phone but doesn't answer

Question

Heloo
When i call to the ip phone with DID from external phone it rings both on the desk phone and remote phone but it doesn’t connect when it is picked from the remot phone and it continues ringing on the desk phone. While it works for calls that are internal.
In addition to this the caller id doesn’t appear in the remote phone instead of the caller id the office number appears.
withe regured
Addisu

Answer 1

Speaking of PSTN connection, note that only circuits with out-of-band signaling are supported. In other words, no analog or T1 CAS circuits as CUCM needs answer supervision from the gateway.
Secondly, the Answer too Soon/Too Late timers become quite important here. CUCM must not see the CONNECT event (or 200 OK if SIP) outside of this window. If it does, CUCM will assume that voicemail answered instead of the user and drop the Remote Destination from consideration. This means the desk phone would start ringing even though the cell stops. Turn up a few debugs to see what the PSTN circuit is telling the gateway and CUCM. When does the call technically connect?
As for caller ID: what does CUCM send as the ANI of the outbound call? If it passes the correct value and you don't see it on the cell phone, the carrier is filtering your ANI. This is common with RBOCs/ILECs with legacy Class5 switches: they only allow you to set a caller ID value to a DID that you own. You may need to ask your carrier how to override this. Some carriers won't let you, others will if you add RDNIS/Diversion header.
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