Network traffic between signaling points may be routed via a packet switch called an STP . An STP routes each incoming message to an outgoing signaling link based on routing information contained in the SS7 message. Because it acts as a network hub, an STP provides improved utilization of the SS7 network by eliminating the need for direct links between signaling points. Because the SS7 network is critical to call processing, SCPs and STPs are usually deployed in mated pair configurations in separate physical locations to ensure network-wide service in the event of an isolated failure. Links between signaling points are also provisioned in pairs.
Traffic is shared across all links in the linkset.
If one of the links fails, the signaling traffic is rerouted over another link in the linkset . The SS7 protocol provides both error correction and retransmission capabilities to allow continued service in the event of signaling point or link failures. STP pair in a quad-link configuration.