Subject: Re: Strange (?) tcp_cwm behavior
To: venkat venkatsubra <>
From: Doug Donsbach <>
List: tech-net
Date: 11/22/2002 16:45:07
venkat venkatsubra wrote:
> Doug,
> On AIX the ACKs are triggered by application's
> reading of the data. An NFS client sets MSG_WAITALL
> recv() flag. Which means the data is not delivered to the
> apps till the full 32K arrives.  Without the application's
> read delayed ACK kicks in which is upto 200 millisecs.
> And the sender is waiting for the ACK for the cwnd to
> increase to send more.
> We have done changes to this MSG_WAITALL behavior
> and if you use one of the recent releases (AIX 5.1 for example)
> you will not see this problem.
> Venkat

Thank you, Venkat, for your suggestion.

Doug Donsbach -