From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30210 invoked by alias); 12 Jun 2007 16:08:02 -0000 Received: (qmail 30200 invoked by uid 22791); 12 Jun 2007 16:08:01 -0000 X-Spam-Check-By: sourceware.org Received: from londo.lunn.ch (HELO londo.lunn.ch) (80.238.139.98) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 12 Jun 2007 16:07:57 +0000 Received: from lunn by londo.lunn.ch with local (Exim 3.36 #1 (Debian)) id 1Hy8uP-0002B7-00; Tue, 12 Jun 2007 18:07:53 +0200 Date: Tue, 12 Jun 2007 22:12:00 -0000 To: J?rgen Lambrecht Cc: eCos Discussion , J?rgen Lambrecht Message-ID: <20070612160753.GP26816@lunn.ch> Mail-Followup-To: J?rgen Lambrecht , eCos Discussion , J?rgen Lambrecht References: <466EC08A.8090704@televic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <466EC08A.8090704@televic.com> User-Agent: Mutt/1.5.13 (2006-08-11) From: Andrew Lunn X-IsSubscribed: yes Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: Re: [ECOS] max IP packet size = 9216 B. Why? X-SW-Source: 2007-06/txt/msg00131.txt.bz2 On Tue, Jun 12, 2007 at 05:49:30PM +0200, J?rgen Lambrecht wrote: > Hello, > > I found out that the maximum IP packet size = 9216 B (0x2400). > I implemented an echo program, both udp and tcp. > My ecos applic can receive more that 9216B, but not send back more than > that. > > Has anybody a clue how to solve this? > I need to support the maximum IP packet size of 65535 B (IP_MAXPACKET). Interesting. What network technology do you have underneath this. Something reliable i presume since even small packet error rates are going to cause big delay and inefficiencies with retries. > I don't know if this is a bug in ecos, or a (hidden?) limitation of an > embedded OS. I don't know of anybody else using nearly jumbo packets. So you might be running into bugs, or configuration tweaks might be needed. > I'm busy tracing this back in the source > This comes from the socket that is allocated statically in > /io/fileio/.../fd.cxx and socket is part of a cyg_file (cyg_file is > defined by file in file.h). In cyg_file there is a member f_data, which > is the socket. > I'm continuing my search in the code at this point.... Do you get a crash, or does write/sendto return an error code? Andrew -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss