The two settings above are identical. Basically what you are doing by typing in the numbers, is bypassing the need for DNS to function. DNS is what a system uses to translate the friendly URL (aka - mms.sprintpcs.com) into the real URL (which in this case is 63.215.195.152)
Open up command prompt on your PC and type in "ping mms.sprintpcs.com" without the quotes and you will see the above number displayed.
