[Asterisk-Users] RED ALARM on PRI channel takes Asterisk DOWN

[steve at daviesfam.org]

On Thu, 5 May 2005, Peter Svensson wrote:

> On Thu, 5 May 2005, Vikram Rangnekar wrote:
> 
> > what i noticed is that when i pull any one end of the E1 (breaking the E1
> > connection) I get multiple RED ALARMS on the zap channels I understand this
> > is ok and should happen if the E1 link breaks but my problem is that asterisk
> > stops doing a lot of other things too like i have extensions configured to
> > meetme, voicemail and other aplications they all stop working i get no
> > sound but when i call one hardphone to another it works i guess thats cause
> > the rtp streams go from phone to phone directly. but why does asterisk stop
> > passing anything through itself. Also if anyone else has experience this is
> > this only with sangoma or does it happen with asterisk too. I have a digium
> > card but its a single port and i dont have a real E1 link to test with. )
> 
> All the things mentioned above that stop working when the E1 is 
> disconnected require zaptel clocking. Zaptel clocking is normally derived 
> from the E1 clock, or may be generated internally by a zaptel card. 
> 
> My guess is that the Sangoma card does not switch to internal clocking 
> when the external clocking is lost, thus depriving Asterisk of the zaptel 
> clock source that drives a lot of the internal transmissions. 


Hi,

I've seen exactly the same behaviour with the Sangoma and agree with your 
diagnosis of the cause.

It needs to be raised with Sangoma - the board says its switched to 
internal clocking but /dev/zap/pseudo is still silent in this situation.

Steve