juniper mx80 vs cisco asr 1000

Mark Tinka mtinka at
Sat Jan 28 05:38:57 UTC 2012

On Thursday, January 26, 2012 02:57:59 AM George Bonser 

> If there is a hardware change, you might need to update
> the FPGA images. That is a second file but doesn't
> happen with every release.  In fact, you might not even
> need it of they DO release a new one because the change
> might be for the addition of FPGA images or changes to
> an image for blade you don't even have. But again, it is
> one combined file for all blades.

The issue we have now with IOS XR-based systems is the 
SMU's. Most times, the SMU's need to reload bits of the 
hardware, and it will be different files making different 
updates that each need to reload bits of the hardware 
(fabric, line cards, e.t.c.).

Needless to say, a software upgrade of the main OS on IOS XR 
systems is very lengthy. I'm yet to do it in less than one 
hour, particularly if you're doing SMU's at the same time. 
Here, Junos wins (although, in all fairness, the systems 
aren't the same so maybe not a proper comparison to begin 

But I understand Cisco are working on streamlining this in 
future releases of IOS XR, which would be welcome. While I 
prefer SMU's to ISSU, the majority of them are not entirely 
hitless (contrary to the documentation accompanying an SMU), 
although it will take a shorter time to update via an SMU 
than the main OS, as of today anyway.

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