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Re: Juniper M5/M10 Midplane problems ??
- From: John L Lee
- Date: Mon Jan 06 11:13:25 2003
While I/we have tested the M5/M10 series from Juniper we did not role them
out in the field. The Mid plane design
is / was a standard design to seperate packet, cell, or tdm processing from
the electrical or optical interfaces. You would have to
replace the interface card and cables more often than the processing modules
and you can have the same processing module
drive one or more interface cards.
Usually the mid plane is passive or only has passive (resistor, capacitor,
etc..) components on it for signal enhancement. If the board insertion and
extraction hardware works than bent pins are supposed to be eliminated or
at least minimized. Some designs allow you to insert the board and then when
the pins are lined up apply pressure to positively hold them together. I
am not as familiar with the "new" high denisty board interconnect hardware
but since tolorances are tighter they have to address alighment, insertion
and extraction issues to a greater degree.
In the lab enviroment we swapped cards many more times than you would in
an operational system and did not have a
problem. I presume that the cards are hot swappable ( we tested alot of hardware)
and if that is the case then there needs to be hardware to ground before
circuit contact to not allow floating voltages to destroy the cards cmos
and other static sensitive electronics.
>From a Service perspective I would reccomend one or more spare chassis and
or fully loaded and configured systems for maintenance. The diagnostics usually
allow you to trouble shoot to the board level or power supply level and replace
the FRU (field replaceable unit), but to improve mean time to repair I would
swap out and I would not do a major repair like a midplane replacement in
a POP without space and proper test equipment.
john (I Still Don't kNow) lee
Been looking at a M5/M10 box and have noticed its
not real easy (unless I'm blind) to replace the
Thus I'm wondering what people in the field have
experienced with respect to mid-plane failures.
1. Bent or broken pins on the PIC side
2. Circuit failures
My eval of this product is for a client and their
Other bits of learned wisdom also excepted and