Hello Anamika,
If you are able to pull the SIP pcap, you can check and see why the calls are failing. You can find more info in the following article from the Resource Center:
https://help.mypurecloud.com/articles/sip-diagnostics/
For your CallerID question, you might want to review this article and make some more adjustments to the trunk configuration.
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Jason Kleitz
Genesys - Employees
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