"Support 'Replaces' header" and "Supports Re-Invite?

[pacpac]

Hi, I have connected PAP2T ATA to 3CX. On the extension, do I need to check or un-check "Support 'Replaces' header" and "Supports Re-Invite"?

 

[ITWorks]

I implement these with both checked.

Mark

 

[pacpac]

Hi, with these two boxes check (also only 'Supports Re-Invite') I am not able to get audio when calling extension to extension. Ref my other post; http://www.3cx.com/forums/no-audio-ext-ext-dialing-25718.html