TTCP/RFC1644 problem

[Andre Oppermann]

Danny Braniss wrote:
> hi,
> 	im running some experiments, and it seems to me that
> setting net.inet.tcp.rfc1644 has the reverse effect.
> with sysctl net.inet.tcp.rfc1644 = 0, the transaction uses only 6 packets
> and it's less than 1 sec, setting net.inet.tcp.rfc1644 to 1 uses
> 8 packets and takes more than 1 sec.

The first tcp session in an TTCP connection doesn't gain anything, only
subsequent session can go faster.

You see in the second case that it tries to send data in the packet which
is not ACKed for the first connection and has to be retransmitted.

You should check out the second and third connection to the server and
look how they behave.

Did you enable rfc1644 on server and client?

-- 
Andre


> with net.inet.tcp.rfc1644 = 0:
>     No. Time        Source                Destination           Protocol Info
>       1 0.000000    132.65.80.32          132.65.16.103         TCP      4105 >
>  255 [SYN] Seq=3300562868 Ack=0 Win=57920 Len=0
>       2 0.000038    132.65.16.103         132.65.80.32          TCP      255 > 
> 4105 [SYN, ACK] Seq=3867169834 Ack=3300562869 Win=57344 Len=0
>       3 0.003137    132.65.80.32          132.65.16.103         TCP      4105 >
>  255 [FIN, PSH, ACK] Seq=3300562869 Ack=3867169835 Win=57920 Len=25
>       4 0.003215    132.65.16.103         132.65.80.32          TCP      255 > 
> 4105 [ACK] Seq=3867169835 Ack=3300562895 Win=57895 Len=0
>       5 0.035350    132.65.16.103         132.65.80.32          TCP      255 > 
> 4105 [FIN, PSH, ACK] Seq=3867169835 Ack=3300562895 Win=57920 Len=4
>       6 0.038110    132.65.80.32          132.65.16.103         TCP      4105 >
>  255 [ACK] Seq=3300562895 Ack=3867169840 Win=57916 Len=0
> 
> 
> with net.inet.tcp.rfc1644 = 1:
>     No. Time        Source                Destination           Protocol Info
>       1 0.000000    132.65.80.32          132.65.16.103         TCP      4108 >
>  255 [FIN, SYN, PSH] Seq=967743282 Ack=0 Win=57600 Len=25
>       2 0.000036    132.65.16.103         132.65.80.32          TCP      255 > 
> 4108 [SYN, ACK] Seq=99082279 Ack=967743283 Win=57344 Len=0
>       3 0.002622    132.65.80.32          132.65.16.103         TCP      4108 >
>  255 [FIN, ACK] Seq=967743308 Ack=99082280 Win=57920 Len=0
>       4 0.002671    132.65.16.103         132.65.80.32          TCP      255 > 
> 4108 [ACK] Seq=99082280 Ack=967743283 Win=57920 Len=0
>       5 1.201556    132.65.80.32          132.65.16.103         TCP      4108 >
>  255 [FIN, PSH, ACK] Seq=967743283 Ack=99082280 Win=57920 Len=25
>       6 1.201609    132.65.16.103         132.65.80.32          TCP      255 > 
> 4108 [ACK] Seq=99082280 Ack=967743309 Win=57895 Len=0
>       7 1.227906    132.65.16.103         132.65.80.32          TCP      255 > 
> 4108 [FIN, PSH, ACK] Seq=99082280 Ack=967743309 Win=57920 Len=4
>       8 1.230653    132.65.80.32          132.65.16.103         TCP      4108 >
>  255 [ACK] Seq=967743309 Ack=99082285 Win=57916 Len=0
> 
> 
> 
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