That is kinda what I figured. Thanks for the assistance
and reference.
On Jul 25, 2008, at 12:10 PM, Troy Tate wrote:
> I have an application where all packets seem to have
the PSH/ACK flags
> set (from both sides of the conversation). This is a
barcode
> application. Is this a typical behavior for these
types of
> applications? The user is reporting slow
performance, but I am not
> seeing any network issues other than these flags set
in every packet.
Guy Harris guy@xxxxxxxxxxxx
wrote:
> It is typical behavior for the type of application
called "TCP-based application" to have ACK set on all but
> some of the initial packets; to quote RFC 793:
> Acknowledgment Number: 32 bits
> If the ACK control bit is set this field
contains the value of the next sequence number the sender of
> the segment is expecting to receive. Once a
connection is established this is always sent.
> Whether PSH is set depends on whether the TCP
implementation sets it; that's probably not application-
> specific. In Mac OS X, for example, there's nothing
the application can do to explicitly request PSH; looking
> at the versions of the {Free,Net,Open}BSD TCP code I
had handy, the same is true there. I don't have the
> Linux or Solaris code handy so I don't know whether
they can explicitly force a push, and I don't know what
> other UN*Xes or Windows do.
