[dccp] Question: definition of a window of data packet

[maillist ifiaas <maillist.ifiaas at gmail.com>]

Dear Friends,
While reading the paper "Designing DCCP: Congestion Control Without Reliability", I was confused by CCID2.
In page 7, section 4.2, paragraph 4, line 6~7.
It says: "If the sender did not hear from the receiver that all of the packets in a window of data were received, 
..... "
What does the term "packets of a window of data" means? 
Does it means the sequence of packets that are sent out every time " int(cwnd_) - pipe_ > 0"?
Say if current cwnd_ == 4.35, and pipe_ == 3, "packets of a window of data" is acctually 1 packet. Am I right?

So, in order to tell whether two lost packet is in the same window or not, the sender has to keep some 
"packet seqno <-> window seqno" mappping in mind after sending out the packets?

Please kindly let me know the error if above statement is problemetic.
Thank you very much!

Regards,
Ma Lin

School of Computing,
National University of Singapore