Hello, the DEC750 product description (https://shop.opnsense.com/product/dec750-opnsense-desktop-security-appliance/) has this warning:
Quote
When using SFP+Modules, do not mix 2.5/5Gbps and 10Gbps link-speed as the hardware does not support mixing these due to different frequencies.
However it is not clear to me if I can mix 2.5/5Gbps and 1Gbps link speeds on two SFP+ modules. I know I could just use one of the RJ45 Ethernet ports for the 1Gbps link, but I like the idea of just bumping the link speed if I end up getting better hardware.
Thanks!
If you are talking about the SFP/SFP+, it's highly recommended to have the same on both ends even if one may support various speeds.
So in conclusion, you should never mix SFP/SFP+
I think this refers to the SFP+ slots not being able to support pure 2.5 Gbps adapters at all.
So, you can use SFP modules with 1 Gbps and SFP+ modules, but only at 1 or 10 Gbps native speeds. To be clear, the modules may support 2.5 Gbps external link speed, but it still appears as 10 Gbps to the DEC750.
I have found no way to support 2.5 Gbps GPON modules at native speed above 1 Gbps.
So, I think that you can use one adapter with 10Gbps and another at 2.5Gbps externally, but they will both report 10 Gbps to the DEC750.
And you know that causes confusion in all sorta ways! :)
Thanks! But in my understanding the warning I cited in my original post is about not setting up a 2.5G/5G link in one of the DEC750 SFP+ ports, and a 10G link on the other SFP+ port at the same time. So I am not speaking of links ends, but of module usage on the same device.
I'll rephrase my question. On the DEC750, can I use a SFP+ module on one port, and a SFP (= 1Gbps) module on the other port?
Again, My recommendation is to be identical on both ends.
you can try and YMMV(Your miles may vary)...
Quote from: tonnoplast on February 17, 2023, 02:21:00 PM
Thanks! But in my understanding the warning I cited in my original post is about not setting up a 2.5G/5G link in one of the DEC750 SFP+ ports, and a 10G link on the other SFP+ port at the same time. So I am not speaking of links ends, but of module usage on the same device.
I'll rephrase my question. On the DEC750, can I use a SFP+ module on one port, and a SFP (= 1Gbps) module on the other port?
I got that. I cannot answer to the question as I have not been able to use native 2.5 Gbps devices at their native speed at all. Having said that, I always had the other slot populated with a 10 Gbps device, so maybe this was the reason. Possibly a 2.5 Gbps device would work actually if not mixed with 10 Gbps in the other slot.
Even if it is so, that does not answer your question of mixing any SFP+ module with an SFP module. Have you asked Deciso to elaborate on the warning?
Thanks again. I didn't directly ask, maybe next week I'll drop them an email.
Oh, I forgot: You definitely can mix SFP+ 10 Gbps and SFP 1 Gbps in both slots on the DEC7x0: I actually use this with one DAC SFP+ (10GBase-SFI) for LAN and one GPON stick at 1Gbps (technically 1000Base-SGMII) for WAN.
The latter one could even support 2.5 Gbps, but as I said, I never got it running, probably because of the 10 Gbps DAC in the other slot.
Sorry for bringing up an old thread.
@meyergru could you elucidate about how it works. I have exactly the same setup, except it doesn't work -
DEC740 with DAC SFP+ (auto selected to be 10GBase-SFI) at ax0 as LAN
I have a Luleey GPON stick (https://www.luleey.com/product/2-5g-xpon-stick-sfp-onu/) (manually selected to be 1000Base-SGMII) at ax1.
However, the ax1 shows no-carrier and red. What do I need to do to bring up the Luleey GPON stuck at ax1?
If the Luleey isn't compatible with the DEC700, is there a stick with Realtek RTL9601D that may work?
Quote from: meyergru on February 22, 2023, 09:09:46 AMOh, I forgot: You definitely can mix SFP+ 10 Gbps and SFP 1 Gbps in both slots on the DEC7x0: I actually use this with one DAC SFP+ (10GBase-SFI) for LAN and one GPON stick at 1Gbps (technically 1000Base-SGMII) for WAN.
The latter one could even support 2.5 Gbps, but as I said, I never got it running, probably because of the 10 Gbps DAC in the other slot.
SFP+ slots support at least 1 and 10 Gbps speeds. Only some support 2.5 and 5 Gbps with a mode called HSGMII, which needs different frequencies.
Thus, the dual-slot AX adapter may support SGMII frequency / mode, just not mixed with another module that uses frequencies for 1 or 10 GBps (not withstanding that some SFP+ ethernet modules work with 10 Gbps on the SFP+ side and can adapt to 1/2.5/5/10 Gbps on the ethernet side).
That being said, I think 1000 Mbps SGMII mode is different from "normal" 1000 Mbps mode like what is used in an SFP slot - at least I think I remember to have seen something in the speed and duplex settings of my DEC750 ax interfaces, but I am not sure.
The Luleey modules is known to not work with a Mellanox Connect-X3 and maybe others. Because of the problems with HSGMII speeds, I have switched to external GPON ONTs with 2.5 Gbps ethernet - those work just fine.
At this time, I would probably go directly to an XGS-PON SFP+ stick - it should work with 10 Gbps right away and you can still use it when you ISP makes the switch.
Thanks @meyergru,
Taking on your suggestion - order a media converter now.
And holding my breath for the XGSPON upgrade coming in a decade from Telekom.
I hope if there will be upcoming Luleey firmwares that will solve my potential compatibility issue.
Quote from: meyergru on February 11, 2026, 12:44:45 AMSFP+ slots support at least 1 and 10 Gbps speeds. Only some support 2.5 and 5 Gbps with a mode called HSGMII, which needs different frequencies.
Thus, the dual-slot AX adapter may support SGMII frequency / mode, just not mixed with another module that uses frequencies for 1 or 10 GBps (not withstanding that some SFP+ ethernet modules work with 10 Gbps on the SFP+ side and can adapt to 1/2.5/5/10 Gbps on the ethernet side).
That being said, I think 1000 Mbps SGMII mode is different from "normal" 1000 Mbps mode like what is used in an SFP slot - at least I think I remember to have seen something in the speed and duplex settings of my DEC750 ax interfaces, but I am not sure.
The Luleey modules is known to not work with a Mellanox Connect-X3 and maybe others. Because of the problems with HSGMII speeds, I have switched to external GPON ONTs with 2.5 Gbps ethernet - those work just fine.
At this time, I would probably go directly to an XGS-PON SFP+ stick - it should work with 10 Gbps right away and you can still use it when you ISP makes the switch.