How Net manage tx&rx buffers

Hi:
Does anyone know how QNX net manager manage the tx and rx buffers? For
example, when user is browsing on the net, user may make another request
while net is still receiving data from the previous request.

  1. How does Net know when to flush out the buffered received data?
  2. I am trying to implement the PPPoE on QNX4. When browser is trying to
    download an image file, the data I convert to PPP frame data size will be
    biger then 1516, so I make it into several buffers and feed them to pppd.
    But pppd or browser seems would make the same request again before it
    receives all the data. (My own guess.) I am not sure why the image file
    can’t be display on the voyager browser. The pppd will keep trying to
    transmit out the request and it does get some responses back from the web.
    But after a while, the pppd won’t get any response back from the net even
    though it keep transmitting out the request.

Any idea?

Thanks,
Jackie

On Wed, 18 Apr 2001 19:51:26 -0700, “Jackie” <jackie@neontech.com>
wrote:

Hi:
Does anyone know how QNX net manager manage the tx and rx buffers? For
example, when user is browsing on the net, user may make another request
while net is still receiving data from the previous request.

  1. How does Net know when to flush out the buffered received data?
  2. I am trying to implement the PPPoE on QNX4. When browser is trying to
    download an image file, the data I convert to PPP frame data size will be
    biger then 1516, so I make it into several buffers and feed them to pppd.
    But pppd or browser seems would make the same request again before it
    receives all the data. (My own guess.) I am not sure why the image file
    can’t be display on the voyager browser. The pppd will keep trying to
    transmit out the request and it does get some responses back from the web.
    But after a while, the pppd won’t get any response back from the net even
    though it keep transmitting out the request.

Any idea?

Net “simply” dumps data it receives into the rx buffers you provided
and transmit tx buffer that you fill it. It’s almost that simple.

Net is limited in it’s amount of tx buffer that are shared between
FLEET, TCP/IP and netraw application. You should make sure you don’t
have to many outstanding tx buffer ( I’v always limit it to 10).

I’m don’t clearly understand how you indent on acheiving PPPoE
support, but you’re problem may have more to do with the interface to
pppd then with netraw. I was told at one point that ppp is not only
handle by pppd deamon but also by Socket, at this level this has
nothing to do with Net buffers.



Thanks,
Jackie