Error while connecting to DB through Public IP

While connecting to the DB through a public IP from my system i'm getting an SQL Server does not exist or access denied.But while using localhost its working fine.DB setting in the web.config file.The Code is

<!-- application specific settings -->
 <appSettings>
 <!-- <add key="connString" value="data source=10.1.1.228;initial catalog=ACE;password=XXXX;persist security info=True;user id=sa;packet size=4096" />-->
 <add key="connString" value="packet size=4096;user id=sa;data source=EBIZ;persist security info=True;initial catalog=ACE;password=password" />
 </appSettings>

What to do for this error.Did you try following the connection string advice athttp://www.connectionstrings.com?

Terri