[asterisk-dev] Re: Kernel modules => mainline kernel

[Matthew Fredrickson]

On Feb 14, 2007, at 3:21 AM, Oron Peled wrote:

> On Wednesday, 14 בFebruary 2007 10:01, Khelik Mikhail wrote:
>> Actually to make it feasible all TDM devices in system should be
>> synchronized by TDM bus, because all devices use a clock generators
>> with different parameters, so you'll experience regular slips or skips
>> without true hardware synchronization.
>
> Sure, but zaptel can get the master sync from *one* of
> the low-level drivers (e.g: a PRI card) and than it
> would be hardware based.
>
> Actually, that's exactly how zaptel works today.
> The problem is that this sync is only used to synchronize
> asterisk and not the other low-level drivers.
> [there are some other minor problems. E.g: zaptel does not save
>  the 'prefered' master parameter to zt_register() and so there
>  is no predefined policy about sync master preference (e.g:
>  PRI before FXS)]

Yes, but like Khelik said, unless you synchronize at the driver level, 
or better at the TDM bus level, you have a much greater chance of 
loosing TDM data.  Then you see problems relating to data loss, like 
fax errors, modem errors, etc.

Matthew Fredrickson