FM /Calss to find The RFC Destination(Dynamically) of an ERP system that is connected to Current CRM system

HI Experats,

Need to find the RFC Destination of the ERP Sytem that is connected to thew current CRM system.(We are doing some functionality in CRM at thae same time we need to peform same functinality in ERP System that si connected to Current CRM system )

For that we need to find RFC Destination of Corresponding ERP system we found one class and function module

Class Details: CL_CRM_BUPA_SEPA_FIAR~IF_CRM_BUPA_SEPA_ERP~GET_RFC_DESTINATION

Function Module: SMOF0_READ_SITESELECT

Both returning expected result but we need to know what is the difference which one is the best one to use.

Thanks in advance for your valuable inputs.

Best Regards,

Harsha