Network Write Delay using PPPD

[Mike Siers]

Hi Thomas,
I am currently using the i386/pc586 BSP which does not use 
task driven termios.  Why does PPP require a task driven 
serial driver?  How hard is it to convert an interrupt
serial driver to be task driven?

Thanks for you help
Mike Siers


-----Original Message-----
From: Thomas Doerfler [mailto:Thomas.Doerfler at imd-systems.de]
Sent: Saturday, June 23, 2001 12:43 PM
To: Mike Siers
Cc: rtems-users at OARcorp.com
Subject: Re: Network Write Delay using PPPD


Hello Mike,

I just had another thought concerning your PPP problem: What kind of 
serial driver do you use? The serial device driver used for PPP 
connections MUST (!) use the new "task-driven" termios interface, and 
currently only few BSPs (if any) support this model. So check the 
device driver, if it uses termios polled or interrupt-driven mode, 
problems are to be expected...

Bye,
	Thomas.


> 
> Hi,
> I am using the i386/pc586 BSP with the latest snapshot.  My code
> is using the standard pppd task to establish a network connection.
> The ppp connection gets established and I can create a socket and 
> connect to my server test application.  
> 
> The RTEMS client code will write a block of data every time it 
> receives some data over the socket.  The problem that I am seeing 
> is that the client write seems to be getting delayed.  And the
> delay keeps getting longer after each successive write.  After four 
> writes, the delay is about 90 seconds!  I have turned off the pppd
> compression options.
> 
> I added some debug statements to the pppd code.  Basically it looks
> like the pppoutput function is getting called immediately but the
> modem_sendpacket function call gets delayed.
> 
> Has anyone seen this problem before?  Any thoughts or suggestions
> would be greatly appreciated.
> 
> Thanks
> Mike Siers


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