For setup a ZigBee Network , it needs XB24-XXX or XBP24-XXX , such as XB24-B and XBP24-ZB. " Is that true? Are there different XBee versions for P-to-P and ZigBee?
and 802.15.4(XB24) are different protocols. They are not compatible with each other.
Refer the following link, http://www.digi.com/wiki/developer/index.php/XBee_Product_Codes#DD_upper_word_:_Module_Type which helps you to understand the xbee product codes.