During the very late 1990s there was an initiative to drive
VHE/OSA – Virtual Home Environment and Open Service Architecture.
At that time IN – Intelligent Network – Services were proving popular and there was a need to see if these Services (Charging/Prepaid, VPN,
Number Translation, etc..) can be used in the VPLMN. To help, Network Features were standardised by 3GPP for CAMEL – Customised Application Mobile Enhanced Logic. This led to MAP V3 (and onwards)and CAP V2 (and onwards up to CAP V4). This allowed the home gsmSCF tobe used by the VLPMN. As CAMEL is standardised it promotes interoperability
between different gsmSSF, gprsSSF, gsmSCF, gsmSCF, IP, etc..
If the gsmSCF and the Networks are from the same vendor
then it is possible to triger to different SCPs based on if they are in the HPLMN or the VPLMN