How to Quicken TCP Re-transmission?

[mag at intron.ac]

     Thank you for your reminder. Actually, I understand you and
RFC 2018. What I really concern is how wide support (and being enabled
by default) SACK has obtained. For we do not always transfer data
between hosts running FreeBSD and maintained by network expert.

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                                                From Beijing, China
Mark Allman wrote:

> 
>>      Actually, TCP is a single sliding window protocol, which limits its
>> performance on seriously lossy and long delay transmission media.
>>      We assume that a sender has sent packets [A] [B] [C] [D] [E] while
>> the receiver has received packets [A] [C] [E]. With TCP the receiver can
>> only tell the sender that [A] has reached. If the receiver can notify
>> the sender that both [B] and [D] should be re-sent, the performance will
>> be better.
> 
> One more time: see RFC2018.
> 
> If you actually take a look at that you will see that it provides a way
> for the receiver to indicate that it has received all packets through
> [A] (via the cumulative acknowledgment field) and also that it has
> received [C] and [E] (using selective acknowledgments).  (Knowing that
> [C] and [E] have arrived is basically the same as knowing that [B] and
> [D] didn't.)
> 
> allman
> 
> 
>