Modeling the Internet from the scratch: Link-layer, LAN, Switch - Code snippet: Network Adapter

comm.go

package na

// Card is abstracted network adapter part to simulate bytes transport on
// physical cable. Node's interface uses this interface to send frame
// between nodes.
type Card interface {
    Send(buf []byte, addr string) (time.Time, error)
    Recv() <-chan *FrameData
}