[j-nsp] Juniper RPM Monitoring

[Keegan Holley]

2011/8/25 Saku Ytti <saku at ytti.fi>

> On (2011-08-25 10:36 +0100), Danny Vernals wrote:
>
> > Using it to monitor availability worked fine but if you're planning on
> > monitoring latency and jitter then my findings were to do this you'd
> > need an MS-DPC.  With an MS-DPC the service can use two-way time
> > stamping, without one you can only do one-way timestamping and you're
> > reliant on the RE so results are subject to variance when the router
> > is busy with RPD etc.  There was a significant difference between
> > latency / jitter measured on external probes compared to results based
> > on RPM.
>
> I'd really want to see RPM timestamping implemented in trio. With accurate
> clock source to the router and hardware timestamping RPM could be produce
> much
> better than millisecond accurate measurements regardless of RE related
> latencies.
>
> I recall hearing prior to EX launch that they would timestamp RPM in
> hardware,
> but later someone I know who I know suspected this not to be true due to
> results he was seeing.
>
>
According to the 10.0 release notes RPM timestamping in hardware can be
enabled with a specific command.  I'm checking to make sure this is on all
cards and not just the Trio stuff.  I'll post whatever answers I get.
 Thanks everyone for responding.

■ RPM timestamping extension (MX Series routers)—Adds support for
timestamping of RPM probes in the Packet Forwarding Engine host processer.
On MX Series routers only, you can enable this feature by including the
hardware-timestamp statement at the [edit services rpm probe probe-name
test test-name] hierarchy level.



■ Failure of the Packet Forwarding Engine-based RPM feature with stateful
firewall rules—The Packet Forwarding Engine-based RPM feature does not
support any stateful firewall configurations. If you need to combine RPM
timestamping with stateful firewall, you should use the interface-based RPM
timestamping service. Multiservices DPCs support stateful firewall
processing as well as RPM timestamping.


Keegan