From mboxrd@z Thu Jan 1 00:00:00 1970 From: cathrynham Subject: Re: standard_window_size. Date: Tue, 02 Dec 2008 16:59:14 -0800 Message-ID: <4935D9E2.7000306@junglevision.com> References: <90EE0427-2E1B-4C07-9966-B2D79D3F399B@gmail.com> <2e19719f0812021350y2855cd0fh4eec6280b8b4f1a8@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-hams-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Cc: 'Linux-Hams' Bob Donnell wrote: > > As a more advanced option for serial-port-interfaced TNC's is that I know > that some TNC's can be configured to provide CD information, usually on the > CD line. That information could be used by the AX.25 driver to pause > timers, as an alternate AX.25 driver attachment option. > This sounds like a good idea. If CD is available we only queue the packets when CD transitions from 1 to 0, indicating that the sending station is done transmitting and only after the stack has processed its entire receive queue. Maybe not ideal, I was thinking the ax25 code could wait for 'nothing has been received for XX time' as a way to hackily detect the 'end of transmission' on a half-duplex channel. I'm not sure how you get that 'CD' bit all the way from the TNC up to the Linux ax25 stack. It would be a hideous hack, but could we just write a file to '/proc/net/ax25/ax0/CD and set that to 0 or 1?