[j-nsp] MX104 Limitations

[Kevin Day]

> On Jul 9, 2015, at 10:57 AM, Saku Ytti <saku at ytti.fi> wrote:
> 
> 
>> 1) It’s 3.5U high, making rack planning a little weird, and requiring me to buy a hard to find half-U blank panel
> 
> It is targeting metro applications, where racks often are telco racks. job-1
> and job-2 were thrilled to get MX104 form-factor, MX80 was very problematic
> and lead to 'creative' installations.
> 

I definitely see the appeal there, but in a typical datacenter environment where everything else is using whole numbers for heights, it’s definitely unusual. Out of a few thousand devices, it’s the only half-U sized thing we own.

>> 2) It uses unusual power connectors on its power supplies, so you have to plan to buy special power cords just for this.
> 
> It's standard C15/C16 which is temperature enchanced (120c) version of
> standard C13/C14. Lot of vendors are doing that these days, I'd like to
> understand why. Is there some new recommendation for fire safety or what has
> triggered the change.
> 

The answer I got was that because the MX104 has a much higher temperature range than the rest of their gear, one of the regulatory agencies required that the power cables and your power supply’s *connectors* also be required to handle the higher temperatures.

i.e. you can’t claim your device can handle 100C if your power supply doesn’t have a connector rated for 100C. C13/C14 isn’t rated for that, and you apparently can’t claim your C14 socket can really handle 100C because the standard doesn’t require it.

Not a dealbreaker, but it just means one more weird thing we have to stock.

>> We’re just treating it like an MX240/480/960 that has a pair of MPC’s built in, and a bonus 4x10G MIC.
> 
> The aggregate traffic rates won't exceed 75Gbps/55Mpps, while MX240 with pair
> of MPC2 would be four time the lookup performance and double the memory
> bandwidth. So treating it exactly the same will only work in environment which
> is using capacity sparingly (like metro often does, if your metro legs are
> 20Gbps, then you usually won't see more traffic)

This is true, you definitely can’t treat it like there’s no oversubscription.