[j-nsp] PIC hotswappable?

[Richard A Steenbergen]

On Thu, Jul 15, 2004 at 09:58:09PM +0300, Hank Nussbacher wrote:
> > I think it's just a physical problem, not an electrical one, as the
> > PICs are the same, and probably the FPC bus electronics as well.
> > Just the ejector is missing.
> 
> I was told by the same Juniper SE that M20 PICs can be placed in an M40e -
> but no higher, whereas M40e PICs can go up to the M320, so obviously there
> must be some difference between M20 and M40 PICs.

Ok, I guess its time for the quarterly review of all the PIC combinations 
you can achieve with Juniper.

There are four classes of PICs currently being sold by Juniper:

P	The first PIC Juniper produced, for classic M20/M40. FPC1 only.
PE	The P series PIC, with a physical ejector handle added. FPC1 only.
PB	Denoted by screws on the front, for M160. Can be FPC1 or FPC2.
PC	For T-series FPC3

Electrically, all FPC-type PICs are exactly the same. The FPCs themselves 
are different across different platforms (M5/M10, M20/M40, M160, etc), but 
an FPC1 PIC in an M5 is exactly the same as an FPC1 PIC in an M160.

On the PB class of products, the PIC can be for either FPC1 or FPC2. The
FPC2 PICs are physically larger than the FPC1 PICs, so the PB FPC1 PICs
are just ordinary P/PE PICs with plastic expansion rails screwed onto
them. Low speed PICs (less than 1 Gbps total capacity, in the same
configuration as the cards sole for M5-M40) are for FPC1, and will not 
work in an FPC2. High speed PICs (things like 2x or 4x GE, 4xOC12, OC-48, 
etc) are FPC2, and will not work in FPC1. It's just that simple. :)

M5/M7i/M10/M10i:

* Designed to use PE class cards, with an ejector handle. The FPC is 
  built into the chassis, requiring that the PICs be removable. Comes 
  with a per-PIC offline button.
* Can use P class cards, but with the caveats that alignment is difficult 
  (since there are no plastic guides), and removal is even more difficult 
  (especially if you want to put 4 PICs in a single FPC :P).
* Can use PB FPC1 PICs if you a) remove the plastic rails, and b) remove 
  the metal faceplate or cut the screw ears off of it.


M20/M40:

* Designed to use the P class cards, which have no ejector handle. The 
  FPC is removable, and the design calls for FPC-only hot-swapping and 
  for the PICs to be screwed down to the FPC (al la Cisco VIP style).
* Can use PE cards with no modifications required.
* Can use PB FPC1 PICs if you a) remove the plastic rails, and b) remove 
  the metal faceplate or cut the screw ears off of it.
* Can hot-swap if you a) offline the PIC in question through the CLI 
  first, b) have a physical way to pull the old card out without much 
  grip, and c) are very careful when you insert the card (since there are
  no guides).

M40e:

* In actuality just an M160 on depressants. Takes M160 style FPC1, FPC2,
  and both types of PICs. All other M160 rules apply, except for switching
  capacity.

M160:
* Designed to use PB class cards, which are hot swappable by pulling on 
  the external screws.
* FPC1 style PB cards support PIC hot-swapping through the use of a 
  "little black button" added onto the M160 FPC1.
* FPC2 style PB cards support PIC hot-swapping through the use of a
  "little pinhole button" on the front of the PIC.
* Prevents you from inserting the wrong type of PIC into the wrong type 
  of FPC through the use of mis-aligned screws.
* Can use P or PE style PICs in FPC1 only, if you a) remove the faceplate,
  or screw on an M160 FPC1 style faceplate, and b) screw on the little 
  plastic guide rails from an M160 FPC1.

Maybe I should put up a website with this junk so people don't have to ask 
on mailing lists? :)

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)