RFC 3398, ISUP to SIP Mapping (S): [RFC3398] defines how to do protocol mapping from the SS7 ISDN User Part (ISUP) signaling to SIP. It is widely used in SS7 to SIP gateways and is part of the SIP-T framework.
The Open IMS Core is an implementation of IMS Call Session Control Functions (CSCFs) and a lightweight Home Subscriber Server (HSS), which together form the core elements of all IMS/NGN architectures as specified today within 3GPP, 3GPP2, ETSI TISPAN and