| 摘要 |
In a communication protocol wherein state machines maintained by protocol peer nodes transition state only in response to their current state and the state of the peer node, a packet filter engine (33) on a network node (30) is operative to inspect received protocol packets, and filter out redundant packets. The packet filter engine (33) retrieves a current state of a protocol state machine running on a remote node from a protocol packet, and the current state of the local node from a current state table (40). The two states are used to determine the next state of the local node (30). If the current state of the local node (30) and the next state of the local node (30) are the same, the local state machine will not transition states, and the packet is discarded. If the current state of the local node (30) and the next state of the local node (30) are different, the protocol packet is passed to a processor (44) for updating the local state machine and other processing. The processor (44) updates the current state table (40). In this manner, protocol packets including remote node state information, which will not result in a local state transition, are filtered from the processor (44), relieving its computational load. |
| 主权项 |
1. A method of filtering protocol packets at a first communication network node participating in a communication protocol with a second node, wherein both nodes run state machines defined by the same protocol and wherein the first node protocol state machine transitions in response to its current state and the current state of the second node protocol state machine, the method comprising:
receiving a protocol packet from the second node, the packet including an indication of the current state of the second node protocol state machine; retrieving the current state of the first node protocol state machine; determining, based on the current state of the first and second node protocol state machines, the next state of the first node protocol state machine; comparing the determined next state with the current state of the first node protocol state machine; and if the determined next state differs from the current state, passing the received protocol packet to a processor at the first node; and if the determined next state is the same as the current state, discarding the received protocol packet. |
