3 votes 3 votes In the Ethernet, which field is actually added at the physical layer and is not part of the frame. Preamble CRC Address Location Computer Networks isro2013 computer-networks ethernet + – makhdoom ghaya asked Apr 27, 2016 makhdoom ghaya 6.0k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 10 votes 10 votes preamble and SFD use as physical layer header Prateek kumar answered Jan 24, 2017 • selected Mar 10, 2017 by vamsi2376 Prateek kumar comment Share Follow See all 3 Comments See all 3 3 Comments reply AnilGoudar commented Jul 21, 2017 reply Follow Share Simple doubt, Please help me to understand this, We know Ethernet operates at Data Link Layer, so an Ethernet frame will be formed completely at Data Link Layer itself, then how Physical Layer header is part of Ethernet? Iam confused here, please correct me if i am wrong. 0 votes 0 votes Angkit commented Jun 18, 2018 reply Follow Share Physical layer header is not part of the frame. 0 votes 0 votes JashanArora commented Dec 2, 2019 reply Follow Share AnilGoudar The layers work in order. Any message received by a host will pass through like this: $PL\rightarrow DLL\rightarrow NL\rightarrow TL\rightarrow AL$ Ethernet frame is not "formed" at DLL, but rather DLL attaches some stuff to the bit-streams arriving through PL and calls that a frame. 0 votes 0 votes Please log in or register to add a comment.
9 votes 9 votes The first field(Preamble) of 802.3 frame contains 7 bytes of alternating 0s and 1s that alerts the receiving system to the coming frame and enables it to synchronize its input timing. Preamble is added at the physical layer and is not part of the frame. Nishant Arora answered Apr 27, 2016 Nishant Arora comment Share Follow See all 0 reply Please log in or register to add a comment.
3 votes 3 votes Preamble. It only serves as a header at physical layer but not actually a part of frame and is used for synchronization of input. Ashwani Kumar 2 answered Apr 30, 2016 Ashwani Kumar 2 comment Share Follow See all 0 reply Please log in or register to add a comment.