Question

Need help on these question please!!!

8. How many bytes of overhead are there in an Ethernet frame? Include the header and trailer,

but do not include the preamble in the frame. You will need to look up the length of the

header and trailer.

8a. An Ethernet frame contains 500 bytes of payload data, which is an encapsulated IP packet

from layer 3. Calculate the percentage of the frame that is overhead (do not include the

preamble in the frame). (You will need to use the number of overhead bytes calculated in

the problem above.)

Answer 1

Please find the answers in the attached image

  

8. How many bytes of overhead are there in an Ethernet frame? According to the Ethernet (IEEE 802.3) frame format Ethernet Frames can range in size from 64 bytes (512 bits) up to 1518 bytes (12144 bits) in size The data length is from 46 to 1500 bytes (Without including the header, trailer, and preamble) Preamble SFD (7 Bytes) (1 Byte) Destination Address (6 Bytes) Source Address (6 Bytes) Length (2 Bytes) Data (46 to 1500 Bytes) CRC (4 Bytes) • • Preamble indicates the receiver that frame is coming and allow the receiver to lock onto the data stream before the actual frame begins SFD is the Start of Frame Delimiter and it indicates that the upcoming bits are the starting of the frame, which is the destination address The Ethernet Header contains both Source and Destination Addresses CRC is the Cyclic Redundancy Check • • 8a. Overhead is the additional data that is used in order to send the payload (data inside a packet). That is, we use the following formulae to calculate the overhead percentage (header x 100) Overhead %= -- (payload - header) ------------ The Payload is calculated by the following formulae Payload = Total packet size - header However, need more information about the Total Packet Size, which is missing in the problem.