TCP option 2, Maximum Segment Size

Description Glossary RFCs Publications Obsolete RFCs


Protocol suite: TCP/IP.
Protocol type:Transport layer protocol.
Option length:4 bytes.
Host implementation:
Router implementation:
Links: IANA: TCP option numbers.

The TCP Maximum Segment Size option can be used to specify the maximum segment size that the receiver should use.

MAC header IP header TCP header TCP option 2 Data

TCP Option 2:

0001020304050607 0809101112131415 1617181920212223 2425262728293031
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.



[RFC 793] Transmission Control Protocol.


Obsolete RFCs:

Description Glossary RFCs Publications Obsolete RFCs