Originally Posted by joginder
I think better explaination could be:
a GSM phone will have IMEI which in trun will only with with a SIM card
a CDMA/iDEN will have ESN and will not have any IMEI on it and will not take SIM card.
8830 Worl phone from Verizon has GSM band but its CDMA phone so it has ESN only.
I'd hardly consider this a "better explanation" since most of your post is incorrect.
An iDEN phone does not have an ESN. iDEN uses SIM cards.
The 8830 is a CDMA/GSM hybrid and has both an ESN and IMEI.