[j-nsp] m7i performance

[michael.firth at bt.com]

-----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
sthaug at nethelp.no
> Sent: 21 May 2007 21:05
> To: kanagaraj at aims.com.my
> Cc: juniper-nsp at puck.nether.net
> Subject: Re: [j-nsp] m7i performance
> 
> > - With a RE (512Mb) and CFEB (128Mb), how many eBGP upstream
sessions 
> > (each receiving full routes from provider) can a box take?
> 
> Difficult to give an exact number. However, I would strongly recommend
upgrading your RE-5.0 to the maximum amount of memory, i.e. 768 Mbyte.
> 
I think at some point there is a CFEB RAM upgrade recommended too, but I
guess the need for that will depend on the size of the actual forwarding
table you are pushing down to FEB, rather than the number of different
routes being selected from.

The other RE option to consider is the RE-800, if you can afford it.
This gives more CPU grunt than the old RE-5.0, and also comes with 1.5GB
of RAM by default.

> > - From performance view, how much does a M10i differ from m7i?
> 
> M7i is 3.2 Gbps full duplex for its 4 PIC slots, plus up to 1 Gbps
full duplex for the FIC (onboard) slot. So up to 4.2 Gbps, plus whatever
you can push through the builtin tunnel PIC.
> 
> M10i is 6.4 Gbps full duplex for its 8 PIC slots. If you need a tunnel
PIC, it counts against these 6.4 Gbps.
> 

While this may be the theory, I'm not convinced of this in practice. The
M7i has exactly the same CFEB board as the M10i, and the REs available
are the same, so I think that the actual performance should be pretty
similar. 

The difference, of course, is that in the M7i you can only ever occupy a
maximum of 6 of the 8 available PIC slots. It is slightly annoying that
when you pay to have the optional ASM module installed that Juniper
chose to have this over-ride the built in tunnel PIC, where they could
presumably have had it in addition to the tunnel PIC relatively easily. 
Though there aren't many applications for an M7i where you'd need more
than 800Mbit/s of tunnel PIC capabilities, I'm sure there are ones where
having 800Mbit/s of IPSEC capability and 800Mbit/s of tunnel PIC
capacity would be helpful.

The M10i's main advantage is its redundancy - there is a lot of peace of
mind to be had from having 2 REs and 2 CFEBs available in critical
systems.

> > - One my boxes has 2 eBGP upstream sessions (full routes) and the 
> > memory utilization on RE is constantly around 95%. Is it normal?
> 
> Juniper changed the way memory utilization was calculated, see
> 
> http://marc2.theaimsgroup.com/?l=juniper-nsp&m=116448795729031&w=2
> 
> So RE memory utilization constantly around 95% is pretty normal.
> 
Only, of course, on REs with a relatively limited amount of RAM. On an
M320 or M120 RE (which come with 2GB or 4GB of RAM) the utilisation is
still often only around 20%.

> 
All this is MHO, and nothing to do with my employer, of course.

Regards

Michael

------------------------------------------------------------------------
----
Michael Firth
Video Communication Solutions
BT Exact
* +44 1473 645306
* +44 1473 641333
* michael.firth at bt.com
------------------------------------------------------------------------
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