RFC 2018: TCP Selective Acknowledgment Options

TitleRFC 2018: TCP Selective Acknowledgment Options
Publication TypeRFC
Year of Publication1996
AuthorsMathis, M., Mahdavi J., Floyd S., & Romanow A.
Publication Languageeng
Other Numbers1620

TCP may experience poor performance when multiple packets are lost from one window of data. With the limited information available from cumulative acknowledgments, a TCP sender can only learn about a single lost packet per round trip time. An aggressive sender could choose to retransmit packets early, but such retransmitted segments may have already been successfully received. A Selective Acknowledgment (SACK) mechanism, combined with a selective repeat retransmission policy, can help to overcome these limitations. The receiving TCP sends back SACK packets to the sender informing the sender of data that has been received. The sender can then retransmit only the missing data segments.

Bibliographic Notes

RFC 2018, Proposed Standard

Abbreviated Authors

M. Mathis, J. Mahdavi, S. Floyd, and A. Romanow

ICSI Research Group

Networking and Security

ICSI Publication Type


Citation Key3356