the mtp 3 modules 72 74 are responsible for routing distribution and management of traffic from to the sep 18 fig2 through the signaling links 60 62 terminating on the sep 18 this includes load sharing traffic across available links 60 62 as well as rerouting traffic away from failed links or signaling nodes to perform their functions in compliance with the various national and international ss7 standards the mtp 3 modules 72 74 are configured to maintain state information regarding the status of all signaling links terminating at the sep 18 as well as the status of other network nodes with which the mtp 3 modules 72 74 are concerned the mtp 3 link state includes information regarding whether the link is disabled inactive but not disabled or active whether traffic is inhibited for management reasons locally remotely both or neither and whether a local processor outage condition is indicated locally remotely both or neither this state information is replicated across both boards 40 42 to help ensure that the sep 18 operates in accordance with those standards in the event of a failure of one of the ss7 interface boards 40 42 the mtp 3 layers 72 74 are configured to initialize their internal states to default states indicating that all links are active and all destinations are available the isup modules 80 82 are configured to handle call setup supervision and tear down for circuit switched calls under control of the service applications 44 45 the isup modules 80.