Been looking at a M5/M10 box and have noticed its
not real easy (unless I'm blind) to replace the
mid-plane.
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
infrastructure needs.
Other bits of learned wisdom also excepted and
encouraged 
Thanks
john brown
Hi John,
Been looking at a M5/M10 box and have noticed its
not real easy (unless I'm blind) to replace the
mid-plane.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
infrastructure needs.Other bits of learned wisdom also excepted and
encouraged
First off I think it is good to have a look at the Juniper product line
and consider matching your needs to the right product in the M Series
product line.
In example, if you consider bent or broken pins (which in my opinion is
a serious hardware problem) something you should be able to survive in
case it happens, you should look at a product which gives you
redundancy, or in case of the bigger Junipers, replacable FPC's.
Same goes for the circuit failures. This goes for all routing hardware.
If you want to be able to fix problems in that category, without taking out
the entire box, you should buy one which does enable you to do so, if
in the end you don't want to rule out hardware failure to the midplane.
Although this does not exactly answers your question when it comes to
the M5 platform, I do think this is the proper way to address your
availabilty needs.
Regards,
Dave Aaldering
ISP-Services
john,
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
wrote:
Morning all,
Is anyone else seeing MSN messenger issues? I had verification from a few people that they started seeing problems this morning. At first the messages seemed to be of a server not found message, now it's server error. I didnt see anything on MSN's site.
Does anyone know of a maint page they have?
Thought this also might be helpful to any ISPs with a large amount of users.
David