The Eifel Response Algorithm for TCP

Document Type Expired Internet-Draft (individual)
Authors Ludwig Reiner  , Andrei Gurtov 
Last updated 2002-07-24
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Expired & archived
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The Eifel response algorithm uses the Eifel detection algorithm to detect a posteriori whether the TCP sender has entered loss recovery unnecessarily. In response to a spurious timeout it avoids the go-back-N retransmits that would otherwise be sent, and reinitializes the RTT estimators to avoid further spurious timeouts. Likewise, it adapts the duplicate acknowledgement threshold in response to a spurious fast retransmit. In both cases, the Eifel response algorithm restores the congestion control state in way that avoids packet bursts.


Ludwig Reiner (
Andrei Gurtov (

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