Fast retransmit

Fast retransmit

Fast Retransmit is an enhancement to TCP which reduces the time a sender waits before retransmitting a lost segment.

A TCP sender uses timers to recognize lost segments. If an acknowledgement is not received for a particular segment within a specified time (a function of the estimated Round-trip delay time), the sender will assume the segment was lost in the network, and will retransmit the segment.

The fast retransmit enhancement works as follows: if a TCP sender receives three duplicate acknowledgements with the same acknowledge number (that is, a total of four acknowledgements with the same acknowledgement number), the sender can be reasonably confident that the segment with the next higher sequence number was dropped, and will not arrive out of order. The sender will then retransmit the packet that was presumed dropped before waiting for its timeout.

External links

* [http://www.ietf.org/rfc/rfc2001.txt RFC2001 ] Documenting Slow Start, Congestion Avoidance, Fast Retransmit & Fast Recovery
* [http://www.ietf.org/rfc/rfc2582.txt RFC2582 ] The NewReno modification to TCP's Fast Recovery Algorithm
* [http://www.eventhelix.com/RealtimeMantra/Networking/TCP_Fast_Retransmit_and_Recovery.pdf TCP Fast Retransmit and Recovery Explained via a Sequence Diagram]


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Slow Start — TCP (Transmission Control Protocol) Familie: Internetprotokollfamilie Einsatzgebiet: Zuverlässiger bidirektionaler Datentransport TCP im TCP/IP‑Protokollstapel: Anwendung HTTP SMTP … Transport …   Deutsch Wikipedia

  • TCP-Header — TCP (Transmission Control Protocol) Familie: Internetprotokollfamilie Einsatzgebiet: Zuverlässiger bidirektionaler Datentransport TCP im TCP/IP‑Protokollstapel: Anwendung HTTP SMTP … Transport …   Deutsch Wikipedia

  • Transmission Control Protocol — TCP (Transmission Control Protocol) Familie: Internetprotokollfamilie Einsatzgebiet: Zuverlässiger bidirektionaler Datentransport TCP im TCP/IP‑Protokollstapel: Anwendung HTTP SMTP …   Deutsch Wikipedia

  • Implementaciones de TCP — Este artículo o sección sobre tecnología necesita ser wikificado con un formato acorde a las convenciones de estilo. Por favor, edítalo para que las cumpla. Mientras tanto, no elimines este aviso puesto el 2 de abril de 2011. También puedes… …   Wikipedia Español

  • Network congestion — In data networking and queueing theory, network congestion occurs when a link or node is carrying so much data that its quality of service deteriorates. Typical effects include queueing delay, packet loss or the blocking of new connections. A… …   Wikipedia

  • Port TCP — Transmission Control Protocol Pour les articles homonymes, voir TCP. Pile de protocoles 7 • Application 6 • …   Wikipédia en Français

  • Tcp — Transmission Control Protocol Pour les articles homonymes, voir TCP. Pile de protocoles 7 • Application 6 • …   Wikipédia en Français

  • Transmission Control Protocol — Pour les articles homonymes, voir TCP. Pile de protocoles 7.  Application 6.  …   Wikipédia en Français

  • Transmission control protocol — Pour les articles homonymes, voir TCP. Pile de protocoles 7 • Application 6 • …   Wikipédia en Français

  • TCP congestion avoidance algorithm — The TCP uses a network congestion avoidance algorithm that includes various aspects of an additive increase multiplicative decrease (AIMD) scheme, with other schemes such as slow start in order to achieve congestion avoidance. TCP Tahoe and Reno… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”