Ericsson Research Sonera Corporation 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.