Maximum segment size
The maximum segment size (MSS) is a parameter of the TCP protocol that specifies the largest amount of data, specified in octets, that a computer or communications device can receive in a single TCP segment. It does not count the TCP header or the IP header. The IP datagram containing a TCP segment may be self-contained within a single packet, or it may be reconstructed from several fragmented pieces; either way, the MSS limit applies to the total amount of data contained in the final, reconstructed TCP segment.
The maximum segment size to avoid fragmentation is equal to the largest datagram size that any host is required to be able to reassemble minus the IP header size and TCP header sizes. Therefore IPv4 hosts are required to be able to handle an MSS of 536 octets (= 576 - 20 - 20) and IPv6 hosts are required to be able to handle an MSS of 1220 octets (= 1280 - 40 - 20).
- Comer, Douglas E. (2006). Internetworking with TCP/IP. Vol. 1 (5/E ed.). Upper Saddle River, NJ, USA: Prentice Hall.
- Kozierok, Charles M. (2005-09-20). The TCP/IP Guide (3.0 ed.). Retrieved 2011-09-08.
- RFC 879, page 2, Section 3, "The MSS counts only data octets in the segment, it does not count the TCP header or the IP header."
- RFC 2460, page 28, Section 8.3
- RFC 879, page 1, Section 1
- RFC 2460, page 24, Section 5
- The TCP/IP Guide, TCP Maximum Segment Size (MSS) and Relationship to IP Datagram Size
|This computer networking article is a stub. You can help Wikipedia by expanding it.|