Subject: [tcpm] RFC 2581 Clarification

From: "Leino, Tammy" <[email-masked]>
Date: Wed, 1 Apr 2009 14:29:06 -0600

Hello All,

Can someone please clarify what is meant by "a segment" in step 4 of
section 3.2 when discussing Fast Recovery:

   4.  Transmit a segment, if allowed by the new value of cwnd and the
       receiver's advertised window.

Specifically, could this "segment" be data on the retransmission queue
that has not been ACKed (or retransmitted by Fast Retransmit) or is this
"segment" only new data that has not yet been queued for retransmission?

I had always interpreted this as new data that has not been queued for
retransmission, but in reading RFC 2018 regarding SACK, it seems that
data on the retransmission queue is expected to be retransmitted in Fast
Recovery as this section is outside the scope of the retransmission
timer:

   After the SACKed bit is turned on (as the result of processing a
   received SACK option), the data sender will skip that segment during
   any later retransmission. 

Your insight is greatly appreciated.

Best Regards,
Tammy Leino

---

From: Yoshifumi Nishida <[email-masked]>
Date: Fri, 03 Apr 2009 07:51:10 +0900 (JST)

Hello Leino,

I think you had better refer rfc3517 instead of rfc2581 for this.

Thanks,
--
Yoshifumi Nishida
[email-masked]

From: "Leino, Tammy" <[email-masked]>
Subject: [tcpm] RFC 2581 Clarification
Date: Wed, 1 Apr 2009 14:29:06 -0600
Message-ID: <[email-masked]>