Gateway IP Address for MMS Using SIM900

I am wanting to use a SIM900 GPRS module for sending MMS.

The module will not accept an alphanumeric IP address such as "wireless.cingular.com."  This is for the "AT+CMMSPROTO=" command.

Is there an address in the numeric/dot format that I can use?  I have tried "066.209.11.32" with Port 80 and several variations of this I found on the Internet without success. 

And if  so, does it need the "WAP@CINGULARGPRS.COM"  user name and "CINGULAR1" password?

Thanks.