[Asterisk-Users] Should PRI running over t100p be able to survive short yellow alarms?

[Eric Wieling aka ManxPower]

Kris Boutilier wrote:
> I have a PRI connection between Asterisk and a PBX. The connection passes through a hardware echo canceller which includes some monitoring facilities. Occasionally the T1 has gone yellow for short periods (<2 seconds) and when this occurs Asterisk seems to immediately tear down any in-progress calls. Is this expected behavior or should the established B-channels stay up (sans audio) until the T1 either goes red or a longer period of time (say > 10 seconds) passes?
> 
> I appreciate the best solution would be to fix the cause of the intermittant yellow alarms, however I am curious...

Check your Zaptel card timing setting.  i.e. span=1,1,0,esf,b8zs in 
/etc/zaptel.conf.  The second "1" on the line says "get timing for T-1 
frames FOR THIS CARD from the other end of the T-1"

I have a problem where I have two T-1s from our provider and I'm getting 
the frame timeing from T-1 #1.  T-1 #2 every once in a while goes into 
yellow alarm for a very short time.  There's nothing I can do about it 
because I'm using a 4-port Digium card and there's only one timing 
source per card.