I am new to Fail2ban.  
I have Asterisk VoIP Server running in my lab, and wish to configure fail2ban to block the source IP + source Port, instead of just source IP address alone. 

I have a reason to do this.  If there are multiple IP phones behind a firewall, all of them use same source iP address. 
Assume some phones have right credentials, and can register with Asterisk in first shot, and at least one phone with a bad password. 
Fail2ban can block entire iP based on the bad IP phone. This causes entire IP to be blocked though there are good phones out there.

I appreciate your help.