[j-nsp] MX960 with 3 RE's?

[Niall Donaghy]

That's correct. On MX960 you can have 3 SCBs running 2+1 redundancy or 3+0 performance mode.
With 2 SCBs you run 2+0, ie: without redundancy. In the case of 1 failing, you are 1+0 and on reduced capacity, AFAIK I don't think it's terminal -- just very very suboptimal. :)

With SCBE fabric, here are the Gbps per slot rates:
Redundant mode              2+1        160 Gbps
Performance mode          3+0        240 Gbps

With SCB2E fabric:                          According to JNPR latest figures
Redundant mode              2+1        360 Gbps
Performance mode          3+0        480 Gbps

If you have SCBE fabric and MPC4E cards, then in 2+1 mode you have 280Gbps of ports but only 160Gbps on the slot. In 3+0 mode you have 40 Gbps of oversubscription if you fully load it, etc.
With MPC3E cards, you can only push 137Gbps even though the slot supports 160 Gbps.

We have SCB2E cards on the shelf awaiting rollout to our estate and I'm curious to see what kind of throughput we actually get on MPC4E.

Finally about the REs, you can physically house a spare RE in the dual purpose SCB2 / MPC6 slot but I believe it lacks the additional backplane connections to enable the RE to work, hence it lies there dead.

Kind regards,
Niall

> -----Original Message-----
> From: juniper-nsp [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
> joel jaeggli
> Sent: 13 January 2016 17:07
> To: Colton Conor; Mark Tinka
> Cc: Juniper List
> Subject: Re: [j-nsp] MX960 with 3 RE's?
> 
> On 1/13/16 8:59 AM, Colton Conor wrote:
> > Just to confirm though, its the extra RE that is different and not
> > supported in this config right? The MX960 can use 3 SCB's at once, but
> > only
> > 2 REs? Or do I have the wrong too?
> 
> An mx960 has a full fabric with two SCBs. it is n+1 redundant with 3.
> e.g. at that point you can swap one without cutting the fabric bandwidth in half.
> 
> NSR/GRES uses two REs. a third RE in the chassis is cold and dead. iI's probably
> an acceptable place to store a spare.
> 
> >
> >
> >
> > On Wed, Jan 13, 2016 at 8:16 AM, Mark Tinka <mark.tinka at seacom.mu>
> wrote:
> >
> >>
> >>
> >> On 13/Jan/16 12:42, Jérôme Nicolle wrote:
> >>
> >>> Looks like the broker had a few spare SCB and REs and no functionnal
> >>> chassis to slap them in, so he invented a bundle and didn't fully
> >>> test
> >> it.
> >>
> >> If the price is right, I'd take the extra RE and SCB as backup, in
> >> case not including them does not yield any significant saving.
> >>
> >> Mark.
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