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1 hour ago, R1200CL said:

Still it would be very nice if you can confirm that the 10GB modules or the present SFP+ modules, will work directly between the switch and either of the Sonore devices. 
I couldn’t find the data sheet for that switch, but I expect the SFP+ cage to be both 1GB and 10GB compatible. As it is with the other cheap Mikrotik switch. 

Sorry Andreas, despite my and John's explanations all day today you are still not getting it.

If you put an SFP+ (10Gbe) transceiver into an SFP+ (10GBe) switch cage it is going to transmit at 10Gbe--and that will never be compatible with a 1Gbe SFP component port at other end.

What you are reading about Microtik is that you can plug in a 1Gbe SFP transceiver and it will work with it at 1Gbe.

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27 minutes ago, Superdad said:

Sorry Andreas, despite my and John's explanations all day today you are still not getting it.

If you put an SFP+ (10Gbe) transceiver into an SFP+ (10GBe) switch cage it is going to transmit at 10Gbe--and that will never be compatible with a 1Gbe SFP component port at other end.

What you are reading about Microtik is that you can plug in a 1Gbe SFP transceiver and it will work with it at 1Gbe.


My server has an Intel X520-DA1 NIC that is 10Gbe. If I connect it to my Mikrotik using SFP+ modules at each end, the speed is 10Gbe. If I use SFP modules at each end, then the speed is 1 Gbe. The Mikrotik is a managed switch which reports the speed so I have confirmation of the statements above.

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28 minutes ago, Superdad said:

Sorry Andreas, despite my and John's explanations all day today you are still not getting it.

If you put an SFP+ (10Gbe) transceiver into an SFP+ (10GBe) switch cage it is going to transmit at 10Gbe--and that will never be compatible with a 1Gbe SFP component port at other end.

What you are reading about Microtik is that you can plug in a 1Gbe SFP transceiver and it will work with it at 1Gbe.

I got one of those Mikrotik switches once out of curiosity and I can assure you a 1gb SFP works in it. The switch didn't do anything for me so I returned it up the river. 

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LIVING ROOM: Sonore opticalRendu Roon version (Sonore Power Supply)> Shunyata Venom USB>Naim DAC V1>Witchhat DIN>Naim NAP 160 Bolt Down>Chord Rumor 2>Audio Physic Compact Classics. OFFICE: opticalModule> Sonore microRendu 1.4> Matrix Mini-i Pro 3> Naim NAP 110>NACA5>KEF Ls50's. BJC 6a and Ghent Catsnake 6a JSSG ethernet; AC cables: Shunyata Venom NR V-10; Audience Forte F3; Ice Age copper/copper; Sean Jacobs CHC PowerBlack, Moon Audio DIN>RCA, USB A>C. Isolation: Herbie's Audio Lab. 

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1 minute ago, charlesphoto said:

I got one of those Mikrotik switches once out of curiosity and I can assure you a 1gb SFP works in it. The switch didn't do anything for me so I returned it up the river. 

I had high hopes for the Mikrotik I purchased a while ago, but has the same experience as you. 
 

Happy they work great for others though. They are a bargain. 

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That's what some of us are trying to find out, by listening.
 

What sounds better--to that listener, in that system, etc. At some point, you have to cross the rubicon from theory to practice.
 

At least in my case, I always fall asleep during theoretical listening sessions. 

 

I don't "know" that SFP+ devices will sound better in SFP cages (to me), but I speculate they might, based on some specifications required for 10GB transmission. IIRC some of the network honchos speculated  about that possibility to you/us...that their speed might not be the only benefit, the precision that allowed that speed might have an unintended audio benefit. Might.
 

So, we will try and we will learn.
 

Personally, I had ordered the SFP+ devices from Adrian, confident through reading the specs, Adrian's info/trust, and my acquired knowledge, and you kind of derailed the entire thread with questions, without even digesting the answers. A barrage of questions.
 

Before too long, some readers (me) didn't even know what the hell we were talking about any more. I'm texting Adrian, rechecking stuff I already knew. People from three or four manufacturers are posting. Crazy. And on multiple threads. Helpful eventually gave birth to chaos. 

 

I'll post what I hear, including no difference, when the SFP+ stuff lands. Good luck with your investigations into optical audio. I recommend some reading on the photonics side of things too, if you like deep holes...  
 

 

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20 hours ago, Superdad said:

Sorry Andreas, despite my and John's explanations all day today you are still not getting it.

If you put an SFP+ (10Gbe) transceiver into an SFP+ (10GBe) switch cage it is going to transmit at 10Gbe--and that will never be compatible with a 1Gbe SFP component port at other end.

What you are reading about Microtik is that you can plug in a 1Gbe SFP transceiver and it will work with it at 1Gbe.

 

This is FALSE. The Finisar 10g/1g  SFP+ modules that I have frequently referenced most certainly auto-negotiate to 1G and work with 1g SFP modules at the other end. These are what I use.

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13 minutes ago, jabbr said:

This is true:

 

SOME SFP+ modules will work in SFP ports

SOME SFP+ modules will auto-negotiate to 1Gbs in SFP+ ports

MOST SFP modules will work in MOST SFP+ ports

 

 

 

I've never designed or recommended SFP+ modules in SFP cages. I've had it simply not work before.

 

What I have had work is SFP transceivers in SFP cages, SFP transceivers in SFP+ cages, SFP+ in SFP+ and SFP28 and SFP56 and QSFP+ (by way of adapter).

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2 hours ago, plissken said:

 

I've never designed or recommended SFP+ modules in SFP cages. I've had it simply not work before.

 

What I have had work is SFP transceivers in SFP cages, SFP transceivers in SFP+ cages, SFP+ in SFP+ and SFP28 and SFP56 and QSFP+ (by way of adapter).

Agree! The trend in the newer SFP28 and QSFP28 adapters is that they auto negotiate lower speeds eg you can typically connect a QSFP28 single mode LC-LC cable to a 1Gbe SFP single mode module and it will work. (1000base-LX)

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3 hours ago, jabbr said:

 

This is FALSE. The Finisar 10g/1g  SFP+ modules that I have frequently referenced most certainly auto-negotiate to 1G and work with 1g SFP modules at the other end. These are what I use.


The transceivers themselves do not do any negotiation for speed.  It is determined by the PHY on the circuit board in the switch.

 

Really not sure why the entire industry and networking websites propagate the myth that SFP/SFP+ optical transceivers have any part of the speed negotiations. Even the first link you posted above (https://www.excentis.com/blog/sfp-compatibility-issues-here-are-5-troubleshooting-tips#:~:text=SFP and SFP%2B modules look,switch port and vice versa.&text=Plugging an SFP%2B module into,never auto-negotiate to 1Gbps.) repeats that myth, saying:

“Plugging an SFP+ module into an SFP port delivers no results at all, as the 10G transceiver can never auto-negotiate to 1Gbps.”

 

And your example of a 2.5 watt module was a bit specious because those are for CAT6 Ethernet cable and not for fiber-optic. Yes, I guess John should have qualified his statement to include just fiber-optic SFP+ transceivers. :D

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3 hours ago, jabbr said:

 

This is FALSE. The Finisar 10g/1g  SFP+ modules that I have frequently referenced most certainly auto-negotiate to 1G and work with 1g SFP modules at the other end. These are what I use.


With regards to how that works, John wrote:

 

“There is a pin on the connector that is grounded on the SFP, an SFP+ port can apply a pull up on that port, when SFP is inserted it will be pulled down, an SFP+ will not pull it down so the switch can if it wants to, switch the speed. A switch with SFP+ port is free to either run at just 10Gb, have an external mechanism to change the speed (physical switch, web page configuration etc) or use the above property of SFP modules.”


But again, the SFP/SFP+ transceivers are mostly dumb devices, doing as they are told by whatever they are plugged into.

Even the data itself passed can be nearly anything that you can shove over some differential pairs (LVDS for SFP, CML for SFP+).

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21 minutes ago, Superdad said:


The transceivers themselves do not do any negotiation for speed.  It is determined by the PHY on the circuit board in the switch.

 

Really not sure why the entire industry and networking websites propagate the myth that SFP/SFP+ optical transceivers have any part of the speed negotiations. Even the first link you posted above (https://www.excentis.com/blog/sfp-compatibility-issues-here-are-5-troubleshooting-tips#:~:text=SFP and SFP%2B modules look,switch port and vice versa.&text=Plugging an SFP%2B module into,never auto-negotiate to 1Gbps.) repeats that myth, saying:

“Plugging an SFP+ module into an SFP port delivers no results at all, as the 10G transceiver can never auto-negotiate to 1Gbps.”

 

And your example of a 2.5 watt module was a bit specious because those are for CAT6 Ethernet cable and not for fiber-optic. Yes, I guess John should have qualified his statement to include just fiber-optic SFP+ transceivers. :D

Blah blah blah ... I have no idea why the **entire** industry and my own experience would be wrong but oh well ... that said there is a fair amount of confusion about the issue and results do vary among equipment.  I can say with certainty that “ALL SFP+ modules DO NOT work in any SFP port.  Not even all fiberoptic SFP+ modules. 
 

This thread exists for people to report what actually works with what for this reason, and I have reported my own experiences. I can say with certainty that not all fiberoptic SFP+ modules work with SFP ports. Good manufacturers provide lists of modules that have actually been tested with their products. Do that please. 

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1 hour ago, jabbr said:

Agree! The trend in the newer SFP28 and QSFP28 adapters is that they auto negotiate lower speeds eg you can typically connect a QSFP28 single mode LC-LC cable to a 1Gbe SFP single mode module and it will work. (1000base-LX)


So this SFP28 should be better to use then. Less possibilities for problems.

 

https://ii-vi.com/product-category/products/optical-communications/optical-transceivers/?product-max-data-rate=16g-32g&product-wavelength=1310nm-band

 

The modules is more expensive. Some very much more. 
 

Not so easy to understand what ought to be the best one. All same DFB laser. 
 

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1 hour ago, jabbr said:

Blah blah blah ... I have no idea why the **entire** industry and my own experience would be wrong but oh well ...

...

 I can say with certainty that not all fiberoptic SFP+ modules work with SFP ports.


That’s fine, and really I am not trying to stir up any trouble Jonathan.:/

 

Yet I find it equally odd that the blanket statement “Plugging an SFP+ module into an SFP port delivers no results at all, as the 10G transceiver can never auto-negotiate to 1Gbps” appears verbatim or in some variation all across the web when it simply is not true.

The average pair of SFP+ transceivers, plugged into the average pair of switches with SFP cages, will run just fine at 1Gbe.

Anyone is free to test this.

 

Not that we are even advocating it. Just that the question came up (in part because our Hong Kong dealer is promoting a Finisar SFP+ set to use with EtherREGEN and other switches) and we felt it was appropriate for us to clarify that the fiber SFP/SFP+ modules do not have clocks nor do they determine their own transfer rate (just max capability).  Someone could design a board with SFP cage and run data at some completely arbitrary rate; and if you had two boxes you could plug a SFP+ transceivers into them and run data at 8.3657 Gbe or whatever. :D

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40 minutes ago, Superdad said:


That’s fine, and really I am not trying to stir up any trouble Jonathan.:/

 

well you are contradicting what I’ve said. It’s not stirring up trouble just giving people inaccurate advice. 
 

Quote

 

Yet I find it equally odd that the blanket statement “Plugging an SFP+ module into an SFP port delivers no results at all, as the 10G transceiver can never auto-negotiate to 1Gbps” appears verbatim or in some variation all across the web when it simply is not true.

 

That blanket statement which is essentially the exact opposite, is equally wrong to @JohnSwenson’s blanket statement. I referenced that not because it’s correct, rather that it is the exact opposite. 

Quote

The average pair of SFP+ transceivers, plugged into the average pair of switches with SFP cages, will run just fine at 1Gbe.

Anyone is free to test this.

No such thing as “average” it either works or isn’t.

 

notice the way I worded my statements though. The fact is, if you want “average” then look at fs.com and the link from fs.com that I provided because they sell SFP+ and SFP modules which are compatible with different vendors switches and NICs.

Read https://community.fs.com/blog/can-10gb-switch-port-link-to-gigabit-switch-port.html @JohnSwenson post is not consistent with fs.com either. You need to support your own 1g product but fs.com supports the industry ... who should we believe?

Quote

 

Not that we are even advocating it. Just that the question came up (in part because our Hong Kong dealer is promoting a Finisar SFP+ set to use with EtherREGEN and other switches) and we felt it was appropriate for us to clarify that the fiber SFP/SFP+ modules do not have clocks nor do they determine their own transfer rate (just max capability).  Someone could design a board with SFP cage and run data at some completely arbitrary rate; and if you had two boxes you could plug a SFP+ transceivers into them and run data at 8.3657 Gbe or whatever. :D

 

Yes that is correct ... I don’t want to get into other nitty gritty details such as CDR but one of the big reasons that modules might not be compatible is power usage. There are too many possible combinations which is why I’ve suggested specific modules.

 

Here are a questions for you to ponder:

— why does Finisar specifically make dual 10Gbe/1G SFP+ modules if the modules know nothing about the data rate?

 

The other major disagreement that I have is that it is absolutely NOT necessary to use identical SFP/SFP+ Modules on each end of the connection:

1) you can connect a Cisco switch with an Intel NIC 

2) you can connect a SFP+ switch to a SFP endpoint

 

In my own network only the 100Gbe modules match ... the reasons why open up a can of worms that we don’t want to get into but people like @plissken who deploy professional fiber networks I’m sure have their own opinions in the optimal strategy.

 

Again this thread exists because there are no absolute rules. 

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1 hour ago, R1200CL said:

 


So this SFP28 should be better to use then. Less possibilities for problems.

 

https://ii-vi.com/product-category/products/optical-communications/optical-transceivers/?product-max-data-rate=16g-32g&product-wavelength=1310nm-band

 

The modules is more expensive. Some very much more. 
 

Not so easy to understand what ought to be the best one. All same DFB laser. 
 


Depends on what you mean by “best”. If you mean “tightest eye pattern/lowest phase error” then a SFP28 module in an SFP28 port (25 Gbe) or a QSFP28 (100 Gbe) is “best”,

 

If you mean “best SQ” then according to my own listening experience, it doesn’t matter. 
 

You are free to replicate my own “experiment” though getting a SN2700 switch running using SONiC is not for the faint of heart unless you want to pay $30K retail ... remember that I consider learning how to program an FPGA with a custom Linux device driver “fun” 

 

Thst said if you shop carefully it’s possible. 

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On 3/18/2021 at 9:58 PM, The Computer Audiophile said:

I had high hopes for the Mikrotik I purchased a while ago, but has the same experience as you. 
 

Happy they work great for others though. They are a bargain. 

When you said “high hopes” did you mean SQ wise? Did the switch work correctly? . I have recommended them for the price considering it’s SFP+ ... I’m really not expecting SFP+ switches to have an SQ...  

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On 5/29/2015 at 6:36 PM, jabbr said:

SFPs successfully used with MC220L:

Finisar FTLX8571D3BCL (supposed to be 10g but works ...)


The above quote is from the very first post of this very thread when you started it nearly 6 years ago. Wherein you yourself are reporting about a “10Gbe” SFP+ transceiver working in an “1Gbe” SFP device! Kind of ironic given the hard time you are giving me about our saying so. B|

 

 

11 hours ago, jabbr said:

Here are a questions for you to ponder:

— why does Finisar specifically make dual 10Gbe/1G SFP+ modules if the modules know nothing about the data rate?

 

As John explained clearly, those so-call “dual-rate” modules exist because they provide a means to turn off the pre-emphasis needed when used at high-speed over long distances.

 

 

Quote

The other major disagreement that I have is that it is absolutely NOT necessary to use identical SFP/SFP+ Modules on each end of the connection:

1) you can connect a Cisco switch with an Intel NIC 

2) you can connect a SFP+ switch to a SFP endpoint


We are not at all in disagreement over this. If we stated or implied a need to have the same modules at both ends it was simply because:

a) In the context of using SPF+ transceivers in a 1Gbe device, you can’t have one device with an 10Gbe SFP+ cage and the other be just SFP.

b) There are several parameters (wavelength, media type, etc.) to any transceiver, and for the average person it will be simpler and insure higher chances of success if they just buy matching pairs. (We have found this out the hard way during our support calls; people mis-match important parameters all the time.)

c) To you your last point, that “you can connect a SFP+ switch to a SFP endpoint”: Now it is you possibly confusing folks because you omit the qualifying clause that to connect an SFP+ switch to SFP endpoint one must use 1Gbe SFP transceivers, NOT 10Gbe SFP+ modules.

 

I have a great deal of respect for you Jonathan, and your engineering and networking knowledge and skills are vastly beyond mine (John Swenson is the engineering brain behind our operation). So I have zero desire to argue. Just wanting to be clear with the facts to hopefully aid the general readership.

 

Best,

—Alex C.

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10 hours ago, jabbr said:

Depends on what you mean by “best”. If you mean “tightest eye pattern/lowest phase error” then a SFP28 module in an SFP28 port (25 Gbe) or a QSFP28 (100 Gbe) is “best”,


I think we discussed importance of eye pattern before, so yes. 
Also I suppose your answer would be the same 1GB vs 10GB, so on paper 10GB should be chosen. 
 

But you can’t measure or create an eye pattern without a clock ?

So wouldn’t the measurements depending on switch connected to ?

 

2 days ago I ordered the $99 Mikrotik 610-8G-2S+IN . The two SFP+ ports should cover my needs. 
I like to investigate if this switch somehow can be used to divide network traffic to my audio only by using its web interface. SFF+ for audio.

It has been said by some, that dedicated network sounds better. Probably because of less traffic. 
I don’t expect this way to it will actually work as a separate network. (QOS) I think one should create a subnet. (Different IP address). Which I also have the possibility to do. I have used ipCop for many years. Changed to iPfire last week. (Almost equal UI). This firewall (as many others, as well as some management switches) has the option to create subnets and using firewall rules to open up for communication between the physical divided networks. And my HW used for the firewall allows me use SFP. But this for later discussion. 
 

That 100GB SFPQ28 modules fits any SFP port is interesting. And if I understand you correctly, you’re saying SFP28 and SFPQ28 has a higher probability to work between various of 1GB connected devices. 
 

Now that it has been confirmed that the 10GB FTLX1475D3BTL works very well with the tested devices, it could be attempting to test SFPQ28 as well. I looked up price just for one. More than $1000. I guess chips in switch’s that supports 100GB isn’t cheap either. 
I think most wold spend 2,5K and above on other items in their audio chain than on SFPQ28 modules. 
 

There must be a limit where the quality of item used in your digital chain is considered as good enough. 
Either we’re talking about phase noise numbers for clocks or implementation of fiber in HW communication standard between devices used for audio. 
 

I don’t know what prices was when the 10GB modules first came to market. They been around for some years now. The latest data sheet for the 10GB FTLX1475D3BTL is dated April 1017, so quite new I would say. And at $100 price, it’s possible for most of us to test out. I definitely will one day. 
 

I would expect the quality of the items used in the switches and endpoints matter more than trying better SFP/SFP+/SFP28/SFPQ28 modules. 


I hope some day @JohnSwenson will explain more about what devices to focus on on the digital chain and how everything is connected and can be measured. I think what he is doing in this area is quite ground braking. My understanding is he planning to show how phase noise can be measured throughout the whole chain. Maybe the choice of SFP’s will be understood better as well. I do expect the receiving HW to matter a lot also. 

 

Also the chip manufacturers play an important role. If I understand @Superdad correctly, it’s hard to get the best chips. Long lead times. Low availability, or even not available any more. Making these special products John design, a challenge just to meet the market demands.


 

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3 minutes ago, Superdad said:


The above quote is from the very first post of this very thread when you started it nearly 6 years ago. Wherein you yourself are reporting about a “10Gbe” SFP+ transceiver working in an “1Gbe” SFP device! Kind of ironic given the hard time you are giving me about our saying so. B|

 

Right. I tested a specific module and reported on a specific result!!! I have been advocating this approach for as you say nearly 6 years.

 

My objection was with the statement "ALL SFP+ modules will work in SFP cages" 

I'm not sure I can be more clear about this.

 

3 minutes ago, Superdad said:


We are not at all in disagreement over this. If we stated or implied a need to have the same modules at both ends it was simply because:

a) In the context of using SPF+ transceivers in a 1Gbe device, you can’t have one device with an 10Gbe SFP+ cage and the other be just SFP.

 

You can absolutely use the Finisar 10Gbe/1Gbe dual rate SFP+ module on one side and an SFP on the other

You can typically use any SFP28 module on one side (in a SFP28 port) as these modules typically support 25/10/5/1 Gbe and an SFP on the other side

 

3 minutes ago, Superdad said:

b) There are several parameters (wavelength, media type, etc.) to any transceiver, and for the average person it will be simpler and insure higher chances of success if they just buy matching pairs. (We have found this out the hard way during our support calls; people mis-match important parameters all the time.)

 

Most manufacturers (and I suggest that you do this) list SFP+ modules that are known to work with their equipment. e.g Cisco wants Cisco SFPs, Intel has a list, etc etc etc.

There is no way to connect a Cisco switch to an Intel NIC using manufacturer recommended SFP+ modules that are identical. This recommended matching is reasonable when it fits the application and is appropriate for the equipment.

 

3 minutes ago, Superdad said:

c) To you your last point, that “you can connect a SFP+ switch to a SFP endpoint”: Now it is you possibly confusing folks because you omit the qualifying clause that to connect an SFP+ switch to SFP endpoint one must use 1Gbe SFP transceivers, NOT 10Gbe SFP+ modules.

 

I have been crystal clear on many situations recommending specific modules specifically the 10Gbe/1Gbe dual rate Finisars... Not sure how I can make this point more clearly?

 

3 minutes ago, Superdad said:

 

I have a great deal of respect for you Jonathan, and your engineering and networking knowledge and skills are vastly beyond mine (John Swenson is the engineering brain behind our operation). So I have zero desire to argue. Just wanting to be clear with the facts to hopefully aid the general readership.

 

Best,

—Alex C.

 

@JohnSwenson tends to swoop in and make statements, but the followup clarification falls to you. I also want to be clear with the facts and if anything I've said is ever factually wrong, I am happy to acknowledge. People tend to listen to what you have to say, and it would be great to edit the post e..g. switch the word "ALL" to "SOME" or even "MANY"

 

Alex, No doubt the myriad of different modules gets very confusing! If you guys would like to post the specific modules you've tested and are known to work with your equipment I would love that.

 

Jonthan

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I feel a bit responsible for starting this latest fiber optics discussion. 
I think the subject has been enlightening enough now to not making any more confusion. 
 

I did based on knowledge from this tread as well as internet search, found several sources stating it won’t work. Hence I was afraid @AfterDark. started something that could turn out to be problematic. 
 

Now we know better. And the discussion would happen sooner or later. I think better up front. Now we just have to wait for that one guy that won’t be able to make this 10GB FTLX1475D3BTL to work in his specific setup 😃


Edit:

@jabbr SFPQ28 / SFP28 fits SFP cages ?

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