how can I check logs from Avaya cloud office

edit

Avaya Cloud Office sounds as if it's "VOIP Centrex", i.e. only the user terminals or whatever the Official Phone Term is for phones are at the user premises, and they communicate over the Internet with a phone switch in the cloud.

If so, then, if by "logs" you mean network packet captures (if not, this isn't a job for Wireshark), your network traffic for a call from one soft phone to another will consist of packets sent between each of the phones and a switch on the Internet, so you may not see any traffic from one phone's IP address to the other phone's IP address. Instead, you'll need to capture traffic between the phones and the switch-in-the-cloud.