[asterisk-users] Dahdi for meetme on AMD64 arch?

[Shaun Ruffell]

On Wed, Jan 18, 2012 at 12:58:31PM -0600, Kevin P. Fleming wrote:
> On 01/18/2012 12:15 PM, Johan Wilfer wrote:
> >2012-01-18 17:50, Shaun Ruffell skrev:
> >>
> >> One question first though, is your new server able to keep accurate
> >> time with nt, or is the clock drifting or experiencing heavy jitter?
> >
> > The clock is accurate by ntp sync. It uses the vanilla debian config you
> > get if you "apt-get install ntp".
> > Was it nt(p) you meant above? The clock drifts a lot if it is not synced
> > by ntp. I've noticed most of my hp 360/380 servers to drift up to 10
> > minutes per week, including this server. But ntp fixes this right?
> 
> That's pretty severe, and could certainly cause problems for DAHDI
> trying to use the kernel as a timing source. NTP will correct the
> drift, but the drift is still happening and it's not corrected on
> every tick. If the ticks are not happening at the rate they are
> supposed to, then DAHDI will not be operating at the clock rate it
> is supposed to.

Kevin, this looks like a good candidate for using the "monotonic"
interface in the kernel that we were talking about last week or the
week before. The specific function call escapes me at the moment.

Johan, I can't do it right this second, but I'll prepare an issue /
patch against a 2.6.32 kernel that should make dahdi less prone to
clock skew from NTP (although you probably want to get that fixed
somehow) if you would be willing to test it for me on your server.

Another thing you can try in the meantime is switch to DAHDI 2.5.0.2
and edit drivers/dahdi/Kbuild to enable dahdi_dummy which will use
the (relatively inefficient for the purposes of conferencing)
highres timers when loaded by default on recent kernels (if
compiled in).

Cheers,
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