関連ワード:  physical layer and data link layer    physical layer and data link layer in computer network    difference between physical layer and data link layer    services of physical layer and data link layer    function of physical layer and data link layer    physical layer vs data link layer    describe functions of physical layer and data link layer of osi model    explain the functions of physical layer and data link layer in brief    physical layer coding violations in data link layer    nic is both a physical layer and a data link layer device