[c-nsp] IOS XR

[Mikael Abrahamsson]

On Tue, 6 Sep 2011, Mark Tinka wrote:

> Personally, I don't mind the lack of ISSU. There is no way I'm going to 
> trust that things will go well even when ISSU is supported, so we'll 
> always be running upgrades during outage windows, and not using ISSU 
> just to be sure.

There is also the question about what "ISSU" is. For me, it should be 
hitless or at least sub 50ms traffic hit. As far as I know, none of the 
router manufacturers come even close to this, even when they're talking 
about the future.

Multiple seconds outage is not "in service".

> The worst thing issue I have with IOS XR upgrades is the amount of time 
> it takes to run the patch. Even an SMU can take decades, especially if 
> it needs to reload the line cards/fabric. It's really annoying - almost 
> 1.5hrs upgrading a single box.

Yes, it's a nightmare.

> But, I hear there are plans to significantly reduce the
> upgrades times in upcoming code. Not sure if you need the
> new RP's or if the current ones will do.

Well, "significantly" in this case is not the "order of magnitude" 
improvement that I feel is needed to make this good.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se