cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
646
Views
0
Helpful
2
Replies
bsciarra1
Beginner

Router latency during the night

Good evening.  I've had a strange problem for about a week.  My router is a 3745 with a 9mb multilink circuit.  This is used to route for our mpls WAN links between our branches.  AT&T is our mpls provider. 

During the day when everyone is at work my router runs fine.  At night when there is no load on the router I get latency, average in the 150 msecs.  In the morning when people come to work everything runs well. 

I know about the latency because my NMS sends me emails when the average ping time exceeds a certain amount of msec for a certain amount of time.  And I've been getting these emails all night long.  I know there is barely no traffic because I view my netflow collector for the overnight hours and there is basically nothing going on except snmp requests from my NMS and night time backups.

AT&T says nothing is going on on their end.

It almost seems like when the router has very little traffic it runs bad, then when people show up to work and traffic picks up it runs more efficiently.  Does this behavior make any sense?  Has anyone seen or heard of this before and know what this behavior may be indicative of?

Let me know, thanks...

2 REPLIES 2
paolo bevilacqua
Hall of Fame Master

Session in router at night and check on things first hand.

Maybe some PC backup is being made.

Joseph W. Doherty
Hall of Fame Expert

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Well you described just one router, your 3745 with 6 (?) bundled T1s.  (MLPPP or ATM IMA?)  What's the other side?  Since you also mention MPLS, and branches (plural), can the combination oversubscribe your 9 Mbps?  You also mention "night time backups", do you use any QoS configurations, uses any of AT&T's supported MPLS QoS models, or do you treat all traffic alike?