関連ワード:  define data link layer in osi model    what is data link layer in osi model    explain data link layer in osi model    what is data link layer in osi model with example    what is the data link layer in osi model responsible for    data link layer in osi model function    what is the role of data link layer in osi model    what is the work of data link layer in osi model    what is the use of data link layer in osi model    what is the purpose of data link layer in osi model