Question

How many headers and trailers added in transport layer of tcp/ip?

Answer 1

Headers and trailers are the concepts of OSI model.
Headers are information structures which identifies the information that follows, such as a block of bytes in communication.
Trailer is the information which occupies several bytes at the end of the block of the data being transmitted.They contain error-checking data which is useful for confirming the accuracy and status of the transmission.

During communication of data the sender appends the header and passes it to the lower layer while the receiver removes header and passes it to upper layer. Headers are added at layer 6,5,4,3 & 2 while Trailer is added at layer 2.

Answer 2

Answer:

1 header and no trailer are added in added in transport layer of tcp/ip

Explanation:

The header is a minimum of 20 bytes, but can be as large as 60 bytes. The extra bytes are in the data field (this is a data field in the header - not to be confused with the actual data being transmitted). There is another field that specifies how big the header is to account for the fact that they can be different sizes.

There are 10 + 1 fields in the header. The first 10 are:

1. Source TCP port number (2 bytes)
2. Destination TCP port number (2 bytes)
3. Sequence number (4 bytes)
4. Acknowledgment number (4 bytes)
5. TCP data offset (4 bits)
6. this is the field that specifies the overall size of the header depending on how much data there is in the data field
7. Reserved for future use (3 bits)
8. currently these three bits should be set to zero and not used
9. Control flags (9 bits)
10. Window size (2 bytes)
11. TCP checksum (2 bytes)
12. Urgent pointer (2 bytes)

The eleventh and last field is optional and it is the data field already mentioned above. It might be used for special parameters used by proprietary hardware (etc.)