RJ-45(1/10G) to QSFP+(40G)

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uberguru

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Jun 7, 2013
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Anyone know of an interface to connect an ISP WAN uplink to a QSFP+ port of a router?
Thinking of getting the monster CCR2216-1G-12XS-2XQ router
https://mikrotik.com/product/ccr2216_1g_12xs_2xq



How do i connect RJ-45 devices to this?
 

RTM

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Jan 26, 2014
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I believe Mellanox makes QSFP to SFP+ converters, that you can then plug a SFP+ to RJ45 transceiver into.
Here is a relatively cheap (depending on location) listing on eBay:

You may get more information from this thread:

Whether or not the Mikrotik supports it well is another question.
There have been stories about issues with RJ45 to SFP+ transceivers due to lack of flow control in the transceivers (not limited to Mikrotik).

PS: Could you please stop putting links in text boxes, it is kind of annoying that you have to copy/paste the text to open something that should be a link.
 

koifish59

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Sep 30, 2020
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Specs says that there's already a 1gbe ethernet port. But you can also just use a SFP to RJ-45 module for one of the other 12 SFP28 ports. Something like this:

edit: nevermind, from looking at pics, I think one ethernet port is for management, and the other is for console only.
 

uberguru

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Jun 7, 2013
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Sorry guys, I mispoke too soon, I thought those ports were QSFP+(40G) but they are SFP28(25G)
So the same SFP+(10G) port will fit into SFP28925G) ports as well? and if that is Yes
Then i will assume QSFP+(40G) will also fit into QSFP28(100G) also?
 

uberguru

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Jun 7, 2013
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I believe Mellanox makes QSFP to SFP+ converters, that you can then plug a SFP+ to RJ45 transceiver into.
Here is a relatively cheap (depending on location) listing on eBay:
What i will like is get the 40G to 4 x 10G splitter and then be able to then use RJ-45 on each of the 10G SFP+ modules
Any 40G QSP+ to 4 x 10G RJ-45 and if not then any way to have RJ-45 work with the 4 x SFP+ ports?
 

TLN

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Feb 26, 2016
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What i will like is get the 40G to 4 x 10G splitter and then be able to then use RJ-45 on each of the 10G SFP+ modules
Any 40G QSP+ to 4 x 10G RJ-45 and if not then any way to have RJ-45 work with the 4 x SFP+ ports?
It will be male SFP+ modules. Those do exist.
You can also find MTO to 4x multimode pairs splitter. Nothing with RJ 45 tho.
Your best bet to run that QSFP+ to SFP+ adapter from Mellanox, but I'm not sure if QSFP+ port can do 1G.
 

uberguru

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Jun 7, 2013
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It will be male SFP+ modules. Those do exist.
You can also find MTO to 4x multimode pairs splitter. Nothing with RJ 45 tho.
Link or picture of the 40G to 4 x 10G that i can then connect RJ-45 to for each of the 10G?


Your best bet to run that QSFP+ to SFP+ adapter from Mellanox, but I'm not sure if QSFP+ port can do 1G.
QSFP+ not 1G directly, but 1G via the SFP+ module after splitting 4 x SFP+?
 

TLN

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Feb 26, 2016
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Link or picture of the 40G to 4 x 10G that i can then connect RJ-45 to for each of the 10G?
Oh, I mean splitter, then media converter and so on.

QSFP+ not 1G directly, but 1G via the SFP+ module after splitting 4 x SFP+?
You'll get male end of SFP+, that goes directly into SFP+ cage.

I just checked it on one of our Junipers. I don't have option to set speed under interface. I can run either full speed (40G, interface et-0/0/0 in juniper language) or channelize it into 4x10G (gets me xe-0/0/0:0 though :3).
 

uberguru

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Jun 7, 2013
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I just checked it on one of our Junipers. I don't have option to set speed under interface. I can run either full speed (40G, interface et-0/0/0 in juniper language) or channelize it into 4x10G (gets me xe-0/0/0:0 though :3).
Link to product?
 

TLN

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Feb 26, 2016
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Link to product?
We got stuff like that: Cisco QSFP-4SFP10G-CU1M 40G QSFP+ Breakout DAC Cable - FS
But it's DAC on both ends, and it may not drop speeds to 1G speeds. You'd have better chances with smh like that:

This one can go directly in SFP port (does not require SFP+)
 
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RTM

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Jan 26, 2014
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What i will like is get the 40G to 4 x 10G splitter and then be able to then use RJ-45 on each of the 10G SFP+ modules
Any 40G QSP+ to 4 x 10G RJ-45 and if not then any way to have RJ-45 work with the 4 x SFP+ ports?
I believe the problem is that generally SFP+ to RJ45 transceivers use more power than regular ones, so having to feed power from one port to 4x that may be a bit much.

I was going to write, that you may also have trouble getting the QSFP(28) port split into 4x, but it seems that it is supported, though apparently not controllable (source - though a different device so YMMV).