1. An SS7 signaling message routing node comprising: (a) a signaling link interface module for sending and receiving SS7 signaling messages; (b) a routing rule data structure associated with the signaling link interface module, the routing rule data structure including a first routing rule component having SS7 signaling message routing rule entries based on SS7 destination address information and a second routing rule component having at least one default SS7 signaling message routing rule entry that is not based on destination address information; and (c) a message routing function associated with the routing rule data structure for using SS7 destination information in a received SS7 message to initially search for a matching entry in the first routing rule component, and, in response to failing to locate a matching entry in the first routing rule component, for searching the second routing rule component for a matching entry.