This memo defines a protocol for supporting the transport of any SS7 MTP3-User signalling (e.g.@ ISUP and SCCP messages) over IP using the services of the Stream Control Transmission Protocol. Also@ provision is made for protocol elements that enable a seamless operation of the MTP3-User peers in the SS7 and IP domains. This protocol would be used between a Signalling Gateway (SG) and a Media Gateway Controller (MGC) or IP-resident Database@ or between two IPbased applications. It is assumed that the SG receives SS7 signalling over a standard SS7 interface using the SS7 Message Transfer Part (MTP) to provide transport. This document obsoletes RFC 3332.