2 votes 2 votes according to standards of ethernet minimum data size in LAN is 64bytes in some question by solving L=2Tp*B, i got L value as 60bytes. now answer for this question shud be 60bytes according to the answer or 64 bytes according to standards? Computer Networks ethernet + – Anusha Motamarri asked Jan 25, 2017 edited Jan 25, 2017 by Anusha Motamarri Anusha Motamarri 1.1k views answer comment Share Follow See all 19 Comments See all 19 19 Comments reply sudsho commented Jan 25, 2017 reply Follow Share L means data length right....its from 46 to 1500 B frame length is from 64 to 1518 B 1 votes 1 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share yes correct! now edited. please see 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share ohkk now 46 bytes will be the answer 1 votes 1 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share @sudsho L doesnt include DLL header? we also transmit DLL header rt? 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share no data doesnt include DLL header from DA till CRC we say frame preamble and SFD are not included in DLL frame 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share preamble(7) SFD(1) DA(6) SA(6) length(2) data CRC(4) data should be between 46 to 1500 B DLL header here is DA+SA+length DLL tail is CRC frame is from DA to CRC 0 votes 0 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share yea, but we transmit the complete frame isnt L/B time taken to transmit the entire packet along with all headers? 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share yes but except data everything is fixed...to detect collision in ethernet we need data to be atleast 46 bytes..then frame automatically will become 64 bytes... 0 votes 0 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share i agree that data shud be between 46 to 1500 but here L what we are calculating is the complete frame ryt? example: https://gateoverflow.in/3834/gate2005-it-71 https://gateoverflow.in/3376/gate2008-it-65 https://gateoverflow.in/39589/gate-2016-2-53 if they asked min data size, it would have been L-18 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share in all these questions they have asked minimum frame size..then obviously u'll add header and tail also...depends on question what they have given..generally they will say packet...then it means frame only..if they only say data is this then what will be the minimum data to detect collision then take data into consideration....so depends 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share u send the complete ether net frame...L/B L means packet length or frame length...but if given only data length then take that only 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share ok means ur doubt is whther it should be 46 or 64B right..in the original question u asked? 0 votes 0 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share yeah exactly. :) ..it shud be 64 nly ryt? 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share yes if question says what is the minimum frame size if they ask what is the minimum data size then 46 but they ask frame size only so 64 is right 0 votes 0 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share yes :) 1 votes 1 votes sudsho commented Jan 25, 2017 reply Follow Share one such question was there regading jam bit in previous year paper...answer was coming 464 something...but we should pad 48 bits to make it 512 or 64B for collison detection.. 0 votes 0 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share yes i got this doubt from that question nly :) 0 votes 0 votes sudsho commented Jan 25, 2017 reply Follow Share ok :) frame size should be 64 bytes only else pad same with IPV4 header also...if they say it is between 5-15 bytes means scaling has been done if between 16 to 19 bytes do padding and make 20B else they will give between 20-60B only 1 votes 1 votes Anusha Motamarri commented Jan 25, 2017 reply Follow Share thank you sudsho 1 votes 1 votes Please log in or register to add a comment.