How to verify if IAX2 trunk is properly encrypting

I added encryption to my IAX2 trunk connecting two Asterisk PBXs over the internet.
How do I verify if the encryption is actually happening? Anything to look for in IAX2 debug?

forceencryption=yes
encryption=yes
auth=md5

iax2 show peers will have a ā€˜eā€™ and if you do a pcap capture in wire shark you wont be able to listen to the call

Ian