Hi,

I just saw that Mikrotik released the CRS310-8G+2S+IN device. That's a good move. However there is a design choice on this device which seems to be a recurring pattern since the release of RB5009 which I do not understand: the power port is placed on the front of the device.

What's the rationale behind this decision ? It makes cable management more difficult (both on desktop or in a rack).

Note: When placed in a rack, the RB5009 can be powered using 2pin so there is no issue, but not L009UiGS-RM, nor CRS310-8G+2S+IN.

Regards,

K.

There are use cases for rack equipment where it's good if all wires (data and power) connect from the same side. For example:

• device is mounted in standard IT rack (depth exceeding 1 meter) and it's extremely difficult to reach back side of such device from the other side of rack
• device is mounted on the back side of rack where also PDUs are ... routing power cable via openings on sides of rack is awkward
• device is mounted in a shallow rack without rear opening
• device is mounted back-to-back with another suitable device ... access to anything connecting to back of device is even harder than in cases listed above
• etc.

All the cases above apply to CRS310 ... as it's rack-mountable if using appropriate rack adapters (readily available from MT).

Ideally MT would offer two variants of each device with minor differences, e.g. power plug location, airflow direction, etc. But we get what we get ...

Thanks for your reply and effort to make it as exhaustive as possible.

If the device is primarily thought to be mounted in a shallow rack with no rear / side access nor enough height to have a brush between the device and the front mounted PDU, why not (usually the PSU will take as much height as a 1U brush) . But this seems to me to be a very limited use case. Here are some thoughts about your suggestions:

• CRS310 is primarily a desktop device which can be mounted in a rack, not the other way around. For desktop usage a front power port is kind of awkward.
• If the objective is to have 4 devices side-by-side such as RB5009, the side 2pin port is great, but what about the L009 ? Ok there is a PoE in port but I must be missing something (are users expected to use 4 poe injectors ? A PoE switch in front of the L009s ?)
• Back-to-back devices: maybe this could be a use case but not if there is an exhaust fan (which CRS310 has).
• If the device is mounted on the back side of the rack, usually I would not place it right above the PDU, And would have a brush or any other kind of cable management accessory to make things neat, so cable wouldn't have to go "through" the sides of the rack.
• The same applies in the case of shallow racks with no rear access or a very deep rack: I would use a brush (or in worst case, a patch panel's hole).
• In my opinion having a "security cutaway" in the case for the power cable in the back is more useful than having a front power port.
• Placing the power input port on the front to explain difficult access to the back of the device and meantime placing the nut for grounding on the back of the device is awkward (see the back of the CRS310).

I am wondering if there are no other reasons such as power supply circuitry placement on the PCB (as close as possible to PoE circuitry and as far as possible from WiFi antennas) to avoid interference for instance...

I am wondering if there are no other reasons such as power supply circuitry placement on the PCB (as close as possible to PoE circuitry and as far as possible from WiFi antennas) to avoid interference for instance...

Maybe a large enough hole in the left mounting ear (as the power input plug is on the left side) would help to route the power cable to/from the back side of a racked or desktop device.

Looking at current rack mounting options, this doesn't seem possible for all of them.

I also really dislike this new design. It looks untidy and makes it easier to accidentally dislodge it.