SNMP - monitoring large number of devices

Tue Sep 29 20:26:06 UTC 2015

Pavel,

AFAIK there are no frameworks that solve, or even come close to solving,
this problem.  The first thing to learn is how to do asynchronous SNMP
calls that will let you send out requests without having to wait for the
response.  How you do those will vary by the language that you're using.
Next, figure out to scale the processing and persisting of the returns and
try and learn (without causing an impact) how many simultaneous SNMP
requests your CMTSs will deal with while at the same time handling their
normal load from customer traffic.  BULKGETS are very handy, but they will
also cause problems because some platforms limit the max size of the SNMP
return.

>From my experience building your server side programming to do 50,000
modems in <5 minutes is very doable, but unless your dealing with more than
10 CMTSs you probably can't do it in production without impacting
performance.  Cisco 10Ks still have absolute caps on the amount of SNMP
they will allow and other manufacturers and models do different things that
limit what you can do.

Scott Helms
Vice President of Technology
ZCorum
(678) 507-5000
--------------------------------
http://twitter.com/kscotthelms
--------------------------------

On Tue, Sep 29, 2015 at 4:20 PM, Pavel Dimow <paveldimow at gmail.com> wrote:

> Hi all,
>
> recently I have been tasked with a NMS project. The idea is to pool about
> 20 OID's from 50k cable modems in less then 5 minutes (yes, I know it's a
> one million OID's). Before you say check out some very professional and
> expensive solutions I would like to know are there any alternatives like
> open source "snmp framework"? To be more descriptive many of you knows how
> big is the mess with snmp on cable modem. You always first perform snmp
> walk in order to discover interfaces and then read the values for those
> interfaces. As cable modem can bundle more DS channels, one time you can
> have one and other time you can have N+1 DS channels = interfaces. All in
> all I don't believe that there is something perfect out there when it comes
> to tracking huge number of cable modems so I would like to know is there
> any "snmp framework" that can be exteded and how did you (or would you)
> solve this problem.
>
> Thank you.
>