Patent ID: 7184538
Filing Date: 2007-02-27
Classification: H04L,H04M,H04Q

Abstract:
1. A communication network, comprising: (A) local communication links, (B) a plurality of separately located central office switching systems interconnected via trunk circuits for selectively providing switched call connections between at least two of the local communication links in response to predetermined control data messages, (C) a signaling communication system for two-way communications of said control data messages between at least said central office switching systems, said signaling communication system interconnecting the central office switching systems; (D) a signaling gateway, separate from the central office switching systems and connected to said signaling communications system, said signaling gateway including an interface connected to a remote communications network and configured to exchange said control data messages between said remote communication network and said central office switching systems by way of said signaling communication system, and (E) a signaling system security monitor, separate from the central office switching systems, said signaling system security monitor including a plurality of message templates corresponding to approved individual ones of said control data messages, sequences of such control data messages and informational relationships between the data contents of such data messages, said signaling system security monitor being responsive to said message templates to perform syntax and content dependent screening of said control data messages, said content dependent screening including checking appropriateness of said control data messages in context of (i) a state of the communications network and (ii) prior related messages.