You have that difference because the public OLI, i'm speaking for EMEA, have 10 digits, you have to change the OLI when you have a DID feature active from your carrier.
So, for example, my number is 022441xxxx where 022441 is the fixed part of the number, the rest is for the DID selection.
The system have a parameter in the Telephony -> Dialing Plan -> Public Network called PUBLIC NETWORK CODE, in there you have to fit the fixed part of the number (in my example 022441), doing so the system compose the OLI number in this way [PUBLIC NETWORK CODE] + [PUBLIC OLI NUMBER] (the value you have setted in the specific DN.
In this way you don't need to set the public received number lenght to 10 (or other values), just configure properly the parameter on your BCM.
Hope this will be useful.
Bye ^^