320 V7122 GatewayUser GuideFigure 98 M2UA ArchitectureFigure 99 M2TN ArchitectureMTP2 Tunneling TechnologyThe SS7 tunneling technology is based on a pairing of remote and central gateways, asshown in Figure 100. The remote gateways are configured to backhaul MTP layer 2 signalingover the IP network using standard M2UA protocol (over SCTP protocol). The function of theM2TN entity is to transmit traffic and handle all management events between MTP2 on theTDM side and M2UA's MGC (Media Gateway Controller) entity on the IP side. Only theactual SS7 MSU (Message Signaling Unit) data is sent. Management of the SS7 link isperformed using M2UA without transporting the MTP2 LSSU (Link Status Signaling Unit) andFISU (Fill in Signaling Unit) messages over IP. These messages, in addition to MTP2 timing,are terminated and supported, respectively, by the remote and central sides. Therefore, theMTP2 connections are not affected by the fact that they are transported over IP.
