[Freeswitch-users] Where do I find the ANI in SIP packets?

I have a couple of carriers that terminate calls for me. Most send my ANI and it shows up, for instance, if I call my cell. However, some carriers are telling me that I am not sending ANI and on those calls I am seeing unknown numbers on my cell. How can I verify I am actually sending ANI and where would I find the ANI in the SIP packets? --Don