Does anyone know any regular (and + version?) BiDis available at fs.com that work with Mikrotik? I dug through the list but couldn’t come up with anything matching from FS.com.
I know some users have had good luck with generic FS units, so just wondering if anyone came across some compatible BiDi units.
I tried:
SFP-GE-BX from fs.com
BLSFP-10G23-10 from fs.com
The both came up and identified, but could not link.
I use these units quite a bit in other applications, they are cheap and work great, would be amazing if MT would incorporate them in the future bugfix chain.
They work just fine in every single Routerboard router and switch over ever put them in. I use them for single-fiber links to outbuildings quite often. I just get the “Generic” fs.com ones. I’ve even used a 10gb SFP+ BiDi before.
I’d say that this: https://www.fs.com/de-en/products/37922.html should be the correct one, customized for MikroTik (which you can do). At the other end of the link use this: https://www.fs.com/de-en/products/37925.html. Whether the customizing is strictly neccessary I don’t know (my TP-Link TL-SM321B works without issues in an SFP+ cage of my CCR1036-8G-2S+), but it can’t hurt.
That’s a set of 1000BASE-BX10-U(plink) & -D(ownlink) optics respectively which you need to drive the simplex fiber path.
I’m still a bit puzzled why do I need when I have only a single point to point connection
So one SFP has to type uplink and the other downlink, isn’t it? But why, is there any explanation for this?
DOM support makes sense as well but what else di I need to take into account?
There are multiple SFP-GE-BX, only distance, wavelength and connector type changes. How do I choose the right wavelength?
BiDi gives full duplex connection over single fibre by using different wavelengths for different directions (as opposed to usual setup where pair of fibres is used, one for Tx and the other for Rx, bot ways using same wavelength). So you need a pair of SFPs where one SFP uses some wavelength to transmit while the other one uses same wavelength to receive. The other SFP uses different wavelength to transmit (not to cause interference with Rx path) and the first SFP uses the same wavelength to receive. Which particular wavelengths are used depends on type of fibre used (single-mode versus multi-mode), in multimode it could be 850nm for one direction (i.e. SFP1 Tx … SFP2 Rx) and 900nm for other direction (i.e. SFP1 Rx … SFP2 Tx). For single-mode fibres usually 1310nm and 1550nm are used.
Configuration on ports on both ends does not have anything to do with duplex nature of this connection and should mostly be set to full-duplex.
xWDM systems offer higher capacity over same (usually pair of) fibre by offering multiple independent channels. CWDM SFPs are usually capable of using only single channel (single wavelength) and other (passive) equipment is needed to merge separate light sources into single fibre. DWDM systems are more or less similar to CWDM only that they use narrower bands of light offering larger number of independent channels. Some SFPs can work with multiple channels concurrently.
In usual SOHO/datacentre, where fibre connections are not longer than (a few) 100 metres and pulling a few more fibres is not a problem, the complication of using xWDM technology just isn’t worth doing it.
As I already explained: most of times xWDM SFPs are only capable of using single WDM channel. Even those DWDM SFPs capable of simultaneously using multiple channels usually use those for higher throughput of a single data stream (sort of bonding those DWDM channels). So by using xWDM, you don’t really save on number of ports on active equipment, xWDM system can not be used as a sort of port multiplicator.
The complication of using xWDM (as compared to usual fibre connections):
use of xWDM multiplexers/demultiplexers
These are passive devices which add/drop certain wavelength from “trunk” fibre … and direct that wavelength to separate (pair of) optical connector. This comes with a price: already mux/demux comes with power loss (usually around 1dB per box, there are 2 in the link), it also usually means one additional optical connector (with additional 0.5dB or so loss).
They also come with a price tag. Mikrotik has their own offering, which according to the product brochure, is not exactly the best in the class.
use of xWDM SFPs. They are both more expensive than “normal” ones and one has to be careful to use SFPs with correct wavelength according to the wavelength assigned on MUX. And one has to do it correctly on both ends of link.
I’m not sure if xWDM is actually available for multi-mode optics (other than BiDi) … which means using slightly more expensive fibre cables
“trunk” fibre always runs between pair of MUX boxes … if active equipment, using those xWDM links, is not all concentrated around those two points, it is still necessary to use (lengthy) patch cables. If inter-MUX distance is not considerable, then length of those patch cables could approach length of (hypothetical) direct connection between active equipment.
FYI: my MikroTik vendor uses https://edgeoptic.com/. These are price-wise the same as FS.com cannot tell if are the same or better than FS.com as I don’t know their SFPs but my vendor told me that they never had any problem with those
