$125 - (Dell Labeled) Aquantia AQS-107 SFP+ to RJ45 NBase-T Transceivers

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Juggie

Member
Nov 3, 2018
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I have this sfp+: Wiitek 10GBase-T 10G RJ45 to SFP+ Copper Transceiver 30-Meter, Compatible for Cisco SFP-10G-T-X, Ubiquiti, Mikrotik (Cat 6a/7 or Better) https://a.co/d/grCYkak

It's installed in a brocade 6610 which doesn't support 2.5 or 5g on the SFP+ ports. Flow control is enabled.

On the cable modem side it's connected to the 2.5g port at 2.5g and on the Brocade side it's connected at 10g. Everything works as expected and I can pull 1.5g from my ISP (which is the limit of my subscription).
 

dag

Member
Apr 23, 2020
27
41
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On the cable modem side it's connected to the 2.5g port at 2.5g and on the Brocade side it's connected at 10g. Everything works as expected and I can pull 1.5g from my ISP (which is the limit of my subscription).
Sure. And as long as it works for you, no need to do anything. But take the same module, connect it to a 2.5GbE switch instead of your modem, test it in both directions via iperf, and see what happens.

It's based on a Marvell 88x33x0. I have worked with dozens of those. They work ok as long as you don't stress them too much. Sending out traffic (10GbE host -> 2.5/5GbE host) is their culprit, you most likely can't see it because your upload cap is much lower than 2.5Gbps. On a 2Gbps fiber connection, the issue is very obvious, they don't even sustain 1Gbps (it tends to be all over the place due to the retransmits).

See this thread:
 

Juggie

Member
Nov 3, 2018
41
9
8
Sure. And as long as it works for you, no need to do anything. But take the same module, connect it to a 2.5GbE switch instead of your modem, test it in both directions via iperf, and see what happens.

It's based on a Marvell 88x33x0. I have worked with dozens of those. They work ok as long as you don't stress them too much. Sending out traffic (10GbE host -> 2.5/5GbE host) is their culprit, you most likely can't see it because your upload cap is much lower than 2.5Gbps. On a 2Gbps fiber connection, the issue is very obvious, they don't even sustain 1Gbps (it tends to be all over the place due to the retransmits).

See this thread:
Interesting.

I have some other 2.5g gear so I'll give it a test with iperf3 and check it out.
 

Juggie

Member
Nov 3, 2018
41
9
8
@dag

Wanted to update you that yep I was able to reproduce the issue for sure. I'll have to keep this in mind if I ever upgrade to anything with a better upload speed. That said I do sometimes feel like I have random drop outs so this could potentially be the cause, the iperf3 behaviour was definitely weird.
 

dag

Member
Apr 23, 2020
27
41
13
All the Dell-branded Aquantia SFPs do not support speeds <5GbE (so no 2.5GbE or even 1GbE). The PHY syncs, but not a single packet goes thru at speeds <5GbE. The Aquantia chip inside is labelled AQR107A, the "A" version is a crippled version made by Aquantia for OEMs like Dell who didn't want to see their older switches support multi-gigabit. You guessed it, they want you to buy a new one instead.