[c-nsp] Another weird problem ...

[Garry]

Hi *

had another weird problem I can't really understand ...

OK, we have a customer site hooked up via dual E1 links - two links 
going through two different carriers. I combined the two using a vanilla 
MLPPP, which worked fine for a while.

Then I noticed network performance drop, as well as errors on the 
physical interface of one of the links, which seemed to be caused by the 
carrier connection, so we opened a ticket.

Carrier checked the circuit, located some problems, but I couldn't get 
the line protocol on it anymore, not even a loop configured on the 
digital side (behind the X21-E1 converter) was visible from our end, 
though a link on the customer E1 interface was visible to me.

After trying just about everything short of replacing the hardware 
(customer isn't located at our city, 1h drive), we decided I would drive 
there today and replace either the converter or the WIC-1T.

Out of curiosity, I went in and configured the not working link not to 
use PPP anymore on both sides - and it came up instantaneously... WTF? 
No errors, link seems fine. So I went ahead and configured an additional 
transfer net, as well as the appropriate routes, so no I'm running fine 
with a dual E1, though not w/MLPPP ...

So, any idea what could be causing this??? As I said, the configuration 
was working for a good month or so ...

Tnx, -garry