On Wed, Sep 21, 2011 at 11:37:47AM -0700, Ryan Crowder wrote: > I'm installing it this afternoon. I'll report back if I notice any > problems. > > -----Original Message----- > From: asterisk-ss7-bounces at lists.digium.com > [mailto:asterisk-ss7-bounces at lists.digium.com] On Behalf Of Shaun > Ruffell > Sent: Wednesday, September 21, 2011 11:35 AM > To: asterisk-ss7 at lists.digium.com > Subject: Re: [asterisk-ss7] Poor dahdi_test results > > On Tue, Sep 20, 2011 at 01:13:34PM -0700, Ryan Crowder wrote: > > # chrt -f 99 dahdi_test -v -c 5 > > Opened pseudo dahdi interface, measuring accuracy... > > > > 8192 samples in 8159.824 system clock sample intervals (99.607%) > > 8192 samples in 8239.544 system clock sample intervals (100.580%) > > 8192 samples in 8159.856 system clock sample intervals (99.608%) > > 8192 samples in 8159.833 system clock sample intervals (99.607%) > > 8192 samples in 8239.856 system clock sample intervals (100.584%) > > --- Results after 5 passes --- > > Best: 99.608 -- Worst: 99.416 -- Average: 99.531525, Difference: > > 99.997346 > > Still strange. Although, since the overall result is 99.9x% range I > do not believe you will have any problems in this configuration. > Data is not being dropped, it is just that there is a delay when > it's being delivered to user space or the clock on your system is > jumping around slightly. Ryan, This is a heads up for you. I was looking into something else recently that I think explains what you were seeing in this thread. dahdi-linux 2.5.0.1 has a regression where, for digital cards, a master span may not be selected on initial configuration. If this is the case, even though you have a card installed / configured, the core timer would process your timers and they run somewhere between a 4ms and 10ms interval depending on the HZ setting in the kernel. http://svnview.digium.com/svn/dahdi?view=revision&revision=10205 I bet if you checkout the current 2.5 branch of DAHDI-linux and test with that, you will see more precision in the dahdi_test results. You could also verify this is what you were seeing by putting the span in loopback and then taking it out to have the driver rescan for a master span. For what it's worth, Shaun -- Shaun Ruffell Digium, Inc. | Linux Kernel Developer 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at: www.digium.com & www.asterisk.org
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