VoIP

Homer is work on Web browser.It able to showing lists of CDRs and displaying SIP flow for each call.And you can see raw SIP packet for each call from browser.

IP-PBX that communicates with SIP may use UDP or may be encrypted with TCP/TLS.If it's encrypted, you can't see it with Wireshark.You can see decrypted SIP packets with importing key to Wireshark.