[lwip-users] RTO calculated to 0 msec ???

[Bonny Gijzen]

Hi to all,

 

 

I have been logging my client (using lwIP) for some time and I noticed a problem in my log.

It seems the RTO value (receive timeout) has been calculated to 0 msec at some point,

which causes the segment to be retransmitted instantly:

 

ack timeout @ 0 msec
pcb->sa=12
pcb->sv=-1
pcb->nrtx=0
new timeout=0 msec
rexmit()

 

The next timeout again occurs at 0 msec, so I get a continous serie of retransmissions.

Can anybody explain what the values ->sa and ->sv mean?

And how are they calculated?

 

I have the feeling the ->sv=-1 is the one causing the problem (i.e. causing RTO to be 0)

 

 

Thanks in advance for your insights

Bonny,