A plug of a connector includes plug-side electrode terminals arranged therein, the plug having a first engagement part on one end side in a direction of arrangement of the plug-side electrode terminals and a second engagement part on the other end side. The refractive index of the Ag layer 115a is sufficiently smaller than the refractive index of the semiconductor material used for the semiconductor layer group of the layers 108 through 114. For such traffic that is being transported over a plurality of Network Based Tunnels, this manipulation can be performed by manipulation equipment that may reside in the access server provider’s network between an Access Gateway and a Border Gateway.