[tcpm] Variable "recover" in F-RTO

[Alexander Zimmermann <alexander.zimmermann at nets.rwth-aachen.de>]

Dear all,

I have an understanding problem with aforementioned variable "recover"
in the current version (http://www.tools.ietf.org/html/draft-ietf-tcpm-rfc4138bis-04 
)
of the F-RTO Algorithm.

Section 2.1 The Algorithm (F-RTO, Reno/NewReno Case)

Step 2): When the first ACK after RTO rexmit arrives at the TCP Sender,
we store the highest sequence number transmitted so far in the variable
"recover".

then

Step 2a) Check if the ACK from Step 2) is a DUPACK OR the ACK covers
"recover" but not more than "recover"...


Why is the check like this? IMHO we can only get an ACK that cover  
exactly "recover"
(Lost Retransmission - SIGCOM Paper Section 4.2) or an ACK that cover  
less than
"recover", but we cannot get ACK that cover more than "recover".

Alex


//
// Dipl.-Inform. Alexander Zimmermann
// Department of Computer Science, Informatik 4
// RWTH Aachen University
// Ahornstr. 55, 52056 Aachen, Germany
// phone: (49-241) 80-21422, fax: (49-241) 80-22220
// email: zimmermann at cs.rwth-aachen.de
// web: http://www.umic-mesh.net
//

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