Application of Bloom Filter for GTP Stateful Inspection in Network Processor

The 3rd generation network rely on a key protocol-the GPRS tunneling protocol (GTP). However, GTP itself is not designed to be secure. So it is necessary to inspect the legal GTP channels and protect the backbone. Because a great deal of GTP-U packets transferring in the channels and the 3G firewall is required to check ten thousand GTP channels which needs mass bytes, so a fast and saving space algorithm is needed. A bloom filter algorithm is used to inspect the GTP-U flows. This method takes advantages of multi-threads and hash units of network processor. The analyses prove that the method only store some bit vectors and corresponding counters which needs less space. The experiments show this method can inspect of 1Gbps flow in the GTP channel.