TCP option 2, Maximum Segment Size

Description:

This option can be used to specify the maximum segment size that the receiver should use.


MAC header IP header TCP header TCP option  Data

TCP Option 2:

00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
Kind Length
Maximum Segment Size

Kind. 8 bits. Set to 2.

Length. 8 bits. Set to 4.

Maximum Segment Size. 16 bits.
This field must only be sent in the initial connection request (i.e., in segments with the SYN control bit set). If this option is not used, any segment size is allowed.


Glossary:


RFCs:

[RFC 793] Transmission Control Protocol.