[lwip-devel] [bug #27771] Silly-window-avoidance shrinks window unnecessarily

[Simon Goldschmidt]

Follow-up Comment #1, bug #27771 (project lwip):

The reason seems to be that tcp_update_rcv_ann_wnd() shrinks the window when
called from tcp_receive(), but does not grow it when called from tcp_recved().
The reason is this line:

if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + pcb->mss)) {

together with the line

if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD) 

in tcp_recved(), this looks like the condition to not send updates is
doubled: the first time we prevent growing the window at all, the second time
we prevent sending a direct ACK. I wonder if we have to remove the ' +
pcb->mss' in the first line or if we only have to call
tcp_update_rcv_ann_wnd() only once per received packet instead of multiple
times (i.e. call it after the recv callback is called)?

    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/bugs/?27771>

_______________________________________________
  Nachricht geschickt von/durch Savannah
  http://savannah.nongnu.org/