[Asterisk-Users] determining if a call to a SIP extensions is from a queue

[Damon Estep]

I am using agentcallbacklogin for queues

I have a desire to modify the call behavior to the agents extension if
the call is from a queue (opposed to from a PRI or another extension).

Is there a channel variable that can be read that would indicate the
source channel waiting to be bridged is an agent/queue call?