We have proposed five new TCP options for scaled windows, selective acknowledgments, and round-trip timing, in order to provide efficient operation over large-bandwidth*delay-product paths. These extensions are designed to provide compatible interworking with TCP's that do not implement the extensions. The Window Scale option was originally suggested by Mike St. Johns of USAF/DCA. The present form of the option was suggested by Mike Karels of UC Berkeley in response to a more cumbersome scheme proposed by Van Jacobson. Gerd Beling of FGAN (West Germany) contributed the initial definition of the SACK option.
All three options have evolved through discussion with the End-to-End Task Force, and the authors are grateful to the other members of the Task Force for their advice and encouragement.