Unformatted text preview: a CRC. Which is done ﬁrst by the sender: bit stuﬃng or the CRC? Explain. 3. Why is there an address ﬁeld in the HDLC header? After all, the HDLC is a point-to-point protocol. 4. Give three examples of unnumbered control frames in HDLC. Why are they called ”unnumbered”? 5. What is the purpose of the protocol ﬁeld in PPP? 1...
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- Fall '09
- Frame, English-language films, HDLC, 128K bits-per-second link, unnumbered control frames, data-link layer protocol