Patent ID: 7848339

Claim:
A transmission apparatus for participating in a virtual network constructed on a physical IP network, said transmission apparatus comprising: a node link monitoring unit configured to search an in-subnetwork node, which is a virtual network node existing within a first IP subnetwork that the transmission apparatus belongs to; a gatenode link monitoring unit configured to search an in-subnetwork gatenode, which is a virtual network gatenode existing within the IP subnetwork, wherein the in-subnetwork gatenode is linked to an out-subnetwork node that exists within a second IP subnetwork different from the first IP subnetwork; a detecting unit configured to detect a number of in-subnetwork gatenodes that exist within the first IP subnetwork; and a node link processing unit configured to determine whether a node linked to the transmission apparatus is an out-subnetwork gatenode based on the number of in-subnetwork gatenodes existing within the first IP subnetwork; and a gatenode determining unit configured to determine a predetermined number of in-subnetwork gatenodes by multiplying a number of in-subnetwork nodes with a predetermined ratio.