A Signalling Interworking Solution for Heterogeneous Networking

IP based networking is seen to take the major role in the ongoing network and service converge process. However, a number of other networking solutions exist and it is anticipated that the future services will be carried to users over a diverse set of networks. This implies the need for interworking between the different network concepts and especially interworking between different signalling systems. This paper introduces a signalling interworking solution that integrates IP routing with cell and circuit switching. A previously developed multiprotocol switching platform, which integrates PSTN, ISDN and ATM switching, has been expanded to include IP routing as well. Interworking between IP and ATM networks is based on an MPLS approach and a SIP based solution is used in implementing IP interworking with PSTN and narrowband ISDN. MPLS is used in creating a bridge between IP and ATM networks by mapping IP routing to the link level MPLS labels. In the narrowband solution, SIP is used to provide the means to implement a gateway from an IP network to a connection-oriented narrowband network.