Patent ID: 7684382
Filing Date: 2010-03-23
Classification: H04L

Abstract:
1. A provider network which includes a plurality of edge routers arranged in a boundary between user networks and provides layer 2 connection services between the user networks, at least one of the plurality of edge routers comprising: a transfer unit to receive a packet transmitted between the user networks and transfer the packet; an obtaining unit to obtain information in the packet transferred by the transfer unit; a creating unit to create a flow list in which flow information indicating a flow of a packet which is transferred from a user network side to a provider network side and information indicating whether a traffic state of the flow is normal are registered based on the information in the packet obtained by the obtaining unit; a monitoring unit to monitor a traffic state of the flow of the packet registered in the flow list based on information in a packet which is transferred from the provider network side to the user network side and registering information indicating whether the traffic state of the flow is normal in the flow list, obtained by the obtaining unit; and an output unit to output information indicating whether the flow traffic state of the packet registered in the flow list is normal, to an outside, wherein the monitoring unit includes a searching unit to search for the flow information in the flow list corresponding to the information in the packet transferred from the provider network side to the user network side, and judges a flow traffic state of the packet indicated by the flow information to be normal when the flow information is retrieved.