Hi Steve,

This might not be helpful but I'll throw it out there.  On customers that are 
delivered over an NNI to ourselves we monitor for a "significant traffic drop" 
in observium which looks for the following:-

ANY / OR
ifInOctets_rate         le      2
ifOutOctets_rate        le      2
ifInUcastPkts_rate      equals  0

Delay 3

This works for us but ymmv.  This will alert us to issues including single 
direction which are normally the case.

Best Regards, 
 
James Greig

-----Original Message-----
From: Steven Maddox <[email protected]> 
Sent: 28 March 2023 08:31
To: [email protected]
Subject: Monitoring if leased lines are down via an NNI

Lo,     
        
We use Juniper MX series routers, and take various NNI services from operators 
like TalkTalk, BT Wholesale, etc... Essentially each VLAN they present on the 
same particular Juniper interface is a different leased 
line.   
        
But if a leased line goes down, that subinterface (a Juniper 'unit' with a 
vlan-id on it) doesn't go down.  So a) we don't get any alerts, and b) if the 
customer has a backup leased line, our systems don't know to 
automatically swap to that.     
        
After checking with people like BT Wholesale, it would seem they do get OAM-CFM 
from Openreach, but then neglect to actually pass that upstream to us.  How 
common is this likely to be with other suppliers?  does anyone know if there is 
something stopping BT Wholesale (or others?) 
from passing back this information?     
        
We know we could supply our own hardware to the customer.  But that would mean 
the customer would have the Openreach ADVA NTU, plus their own router (of their 
choosing), *and* a third box from us (sitting in between the other two) acting 
as another NTU... just for this one 
purpose of generating our own OAM-CFM.  
        
Although we deal with Openreach directly for exchanges we've opened up locally 
(so locally we don't have this issue)... if we're providing leased lines 
further afield (e.g. sold via BT Wholesale, TalkTalk,
etc...) then we can't guarantee a timely replacement of such an extra NTU (that 
we've supplied) should it fail, as we don't have engineers 
that far out.   
        
One thought was to monitor a thing that the customer was likely to have. 
  This might be to poll for ICMP or listen for BFD polls from their router, and 
then if it stops... to have the Juniper disconnect what that unit is connected 
to (e.g. a psuedowire across our MPLS core to where IP or VPLS services are 
delivered) but continue to listen on the unit to see if it comes back.  But 
there doesn't seem to be any elegant 
configuration to do this, that we're aware of.  
        
Just wondering if anyone had encountered this scenario before and what 
might be best practice? 
        
Thanks  
        
--      
Steven Maddox   
Business Systems Engineer       
Internet Central Limited        
        
Registered in England & Wales number 03079542 at Ivy House Foundry, 
Stoke-on-Trent, ST1 3NR.  VAT registration number GB278923705.  Read our 
disclaimer at http://ic.uk/legal before acting on this e-mail.  
        

Reply via email to