Effects of Ensemble-TCP

Effects of Ensemble-TCP

Eggert, Lars and Heidemann, John and Touch, Joe
USC/Information Sciences Institute

Lars Eggert, John Heidemann and Joe Touch 2000. Effects of Ensemble-TCP. ACM Computer Communication Review. 30, 1 (Jan. 2000), 15–29.


TCP currently recalculates the state of each connection from a fixed set of initial parameters; this recalculation occurs over several round trips, during which the con-nection can be less than efficient. TCP control block sharing is a technique for reusing information among connections in series and aggregating it among connec-tions in parallel. This paper explores the design space of a modified TCP stack that utilizes these two ideas, and one possible design (E-TCP) is presented in detail. E-TCP has been designed so that the network transmission behavior of group of parallel E-TCP connections closely resembles that of a single TCP/Reno connection. Simulated web accesses using HTTP/1.0 over E-TCP show a significant performance improvement compared to TCP/Reno connection bundles. This paper is first to evaluate performance using four different intra-ensem-ble schedulers for different workloads. In one scenario simulating a common case, E-TCP is 4-75% faster than Reno for transmitting the HTML parts of various pages, and 17-61% faster transmitting the whole pages. In the same scenario, reusing cached state speeds up repeated E-TCP page accesses by 17-53% for the HTML parts and 10-28% for the whole pages, compared to the initial access. E-TCP can also be integrated with other pro-posed TCP extensions (such as TCP/Vegas or TCP/SACK), to further improve performance.


  author = {Eggert, Lars and Heidemann, John and Touch, Joe},
  title = {Effects of Ensemble-TCP},
  journal = {ACM Computer Communication Review},
  year = {2000},
  sortdate = {2000-01-01},
  project = {ant, lsam},
  jsubject = {www},
  volume = {30},
  number = {1},
  month = jan,
  pages = {15--29},
  location = {johnh: folder: lsam},
  keywords = {ensemble-tcp, tcp batching},
  url = {http://www.isi.edu/%7ejohnh/PAPERS/Eggert00a.html},
  psurl = {http://www.isi.edu/%7ejohnh/PAPERS/Eggert00a.ps.gz},
  pdfurl = {http://www.isi.edu/%7ejohnh/PAPERS/Eggert00a.pdf},
  myorganization = {USC/Information Sciences Institute},
  copyrightholder = {author}