When PIX is using nat for H.323, PIX changes source IP address of packet header in order to send it to the host in the internet.
But H.323 protocol has source ip address in the data portion of incoming packet to PIX. And the destination host in the internet uses the ip address in the data portion in order to send back to the client in the intranet.
I am wondering how PIX can handle ip address mismatch between ip address of packet and that of data portion.