Note that we will only have one mx480 (current cr3-esams), the other router will be the current cr3-knams (mx204).

Future refresh will replaced that mx480 with a device similar to a mx204. So it might be better to keep the mx204 at the top, as well as space for the mx480 replacement.

Ideally we should also have 1 patch panel per rack.

In T331886#8688402, @ayounsi wrote:

Note that we will only have one mx480 (current cr3-esams), the other router will be the current cr3-knams (mx204).

Future refresh will replaced that mx480 with a device similar to a mx204. So it might be better to keep the mx204 at the top, as well as space for the mx480 replacement.

Ideally we should also have 1 patch panel per rack.

In reviewing the contract, its "Precabling/Patc h Panels : Fiber – 6 Ports" so it's a bundle and likely has to terminate in the same panel (or its no longer a bundle really.) We can ask I suppose, but I'd err towards 1 patch panel with 6 ports landing in 1 rack.

How long will the expectation of 1 MX204 + 1 MX480 run?

One of my concerns is our other caching sites use matched routers for redundancy and we could always shift one circuit to another router, which is slightly more complicated (or impossible) with MX480/MX204 split.

I hate the idea of a ton of space in one rack bottom for MX480, but then space at the top since then both racks will not be mirrored. If it is 1 MX480 for a short run, I'd almost prefer just putting all the servers racked fromtop down so future refresh can keep things mirrored.

In reviewing the contract, its "Precabling/Patc h Panels : Fiber – 6 Ports" so it's a bundle and likely has to terminate in the same panel (or its no longer a bundle really.) We can ask I suppose, but I'd err towards 1 patch panel with 6 ports landing in 1 rack.

We need at least 12, see T315937#8215121 so ideally 6 in each.

How long will the expectation of 1 MX204 + 1 MX480 run?

Looking at the device with the most recent linecards: https://netbox.wikimedia.org/dcim/devices/1898/inventory/ I'd expect at least 2 years if not more before we have to procure a new one (and justify replacing the whole box).

One of my concerns is our other caching sites use matched routers for redundancy and we could always shift one circuit to another router, which is slightly more complicated (or impossible) with MX480/MX204 split.

Not sure I understand what you mean here

In T331886#8688615, @ayounsi wrote:

One of my concerns is our other caching sites use matched routers for redundancy and we could always shift one circuit to another router, which is slightly more complicated (or impossible) with MX480/MX204 split.

Not sure I understand what you mean here

I think the comment is related to the two CRs being different models, so port layout etc. being different. Tbh it's always a manual call moving a circuit from one device say, so I think this is not a massive amount of additional complexity. Makes dealing with remote hands a bit harder but I think we should manage?

In T331886#8688489, @RobH wrote:

I hate the idea of a ton of space in one rack bottom for MX480, but then space at the top since then both racks will not be mirrored. If it is 1 MX480 for a short run, I'd almost prefer just putting all the servers racked fromtop down so future refresh can keep things mirrored.

Ideally, longer-term, it would be nice to have both racks fairly symmetric. But I'm not sure what the plan here would be, the MX204 I don't think will need refresh in 2 years time, thus we will replace the MX480 with something else that doesn't match.

Unless we want to replace both at that stage?

Unless we want to replace both at that stage?

Probably not

Ideally, longer-term, it would be nice to have both racks fairly symmetric. But I'm not sure what the plan here would be, the MX204 I don't think will need refresh in 2 years time, thus we will replace the MX480 with something else that doesn't match.

Hard to tell what the landscape will look like, but unless special crisis and seeing how popular the 1U routers are, I'd bet there will be MX204s or MX205s by that time. Worse case, a MX304 (2Us).
cr3-knams is from 2019, so we could maybe refresh it one year sooner and the MX480 1 year later to do both at the same time, or the MX480 2 years later, etc.

@RobH @ayounsi in terms of the CR to ASW connectivity I think this makes sense?

As per discussion on IRC we can re-use the 40GBase-LR4 QSFP+ optics in the MX480 we'll bring over (cr4-knams). We should order an additional 3 (2 for the l MX204 to ASW links, plus 1 spare).

We need 5 single-mode LC-LC patches (including 1 spare) in appropriate lengths to connect the 4 ports listed in my previous comment.

In T331886#8688489, @RobH wrote:

In T331886#8688402, @ayounsi wrote:

Ideally we should also have 1 patch panel per rack.

In reviewing the contract, its "Precabling/Patc h Panels : Fiber – 6 Ports" so it's a bundle and likely has to terminate in the same panel (or its no longer a bundle really.) We can ask I suppose, but I'd err towards 1 patch panel with 6 ports landing in 1 rack.

I'd missed this part of the discussion. I asked them today if they could split out the fibre panel across 2 racks. Let's see what they say.

I was assuming the positions they gave us were for duplex ports, in other words X1-12 represented 12 fibre pairs. If we've only ordered 6 we'll need to get more, as we've 8 circuits at the moment. Let's wait and see what the response to my mail is.