BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s

BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s

BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-28 11:32:07
Model: Archer BE800  
Hardware Version: V1
Firmware Version: 1.2.4 Build 20250414 rel.18315(4153)

I have two BE800 connected via SFP+  in a main router/ access point configuration. 

I have purchased and tested with 2 x Finisar FTLX8574D3BCL SFP+ modules connected with 15M OM3 Fibre.
When this kept dropping to 1Gbps I purchased and tested 2 x Ampcom AM3-SFP-XG-SX-MM850  SFP+ modules connected with 10M OM5 Fibre .

 

In both cases they connect fine at at 10 Gbps Full Duplex but  if left for a couple of hours the link will downspeed to 1 Gbs Full Duplex .
I dont know how long this takes because it isnt reported or recorded in the log, and the Tether app does not report actual interface connection speeds (!). 
I learn about it when my NAS copy speeds drop from 560Mbps to 113Mbps  or when I log into the web interface. 

The only way to restore full speed is to disconnect the fibre and reconnect or reboot both ends of the link. 

I assume this may be a power saving feature but there needs to be a way to bring the link back up when there is activity on it.  

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#1
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9 Reply
Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-29 06:14:18 - last edited 2025-07-29 06:16:28

Hello@StFual ,

Welcome to our community.

 

May I know if your network topology diagram is as follows:

Main router—2* SFP+ modules—2*BE800 )))((( client devices

(Note: — stands for wired connection,)))((( stands for wireless connection )

 

Are both BE800 working in Access point mode?

Please let me know the model of your main router.

 

Whenever the speed drops, have you tested the wired speed directly from the main router?

In addition, please take screenshots of the speed test results on the web management page.

 

Thank you.

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#2
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-29 11:48:52 - last edited 2025-07-29 12:03:13

  @Joseph-TP 

 

To repeat -  I have two BE800 connected via SFP+  in a main router/ access point configuration. 

 

ISP Fiber gateway (Huwaei)-----1Gbe-----BE800 Main-----10GSFP+ Fibre--------BE800 Access Point

BE800 Main - Devices

PPPoE Wan connection to ISP gateway  1 x 1G

SFP+ connection to BE800 AP  1 x 10G Fibre

Qnap NAS 2 x 2.5G

Laptop  1 x 2.5G

 

BE800 Access Point - Devices

SFP+ connection to BE800 Main  1 x 10G Fiber

VR streaming Desktop 1 x 10G

LG  TV  1 x 1G

Nvidia Shield 1 X 1G

LG TV 1 x  WiFi 5

VR Headset  1 x WiFi 7  

 

The speed randomly drops between the two BE800 from 10G to 1G  - the only way i can see this drop is via the web interface or by a collapse in copy time between BE800 main and BE800 access point.  The only way i know to fix it is unplug one of the fiber modules or reboot one or both routers.   

 

 

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#3
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-31 02:54:59

Hello@StFual ,

To assist you efficiently, I've forwarded your case to the TP-Link support engineers, who will contact you using your registered email address later. Please keep an eye on your email inbox for follow-up.

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#4
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-31 07:53:34
I have been able to recreate the problem - not consistently - by switching off the BE800-AP and switching back on again. It sometimes comes back as degraded 1G not 10G. In my limited testing if i do a software restart it does not cause or solve the problem. Once the link has degraded the only way I have found to solve it is to power down the BE800-Main and power up again.
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#5
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-07-31 09:11:29

Hi  @StFual ,

Thank you for your reply with test results.

I'd like to confirm that the backlink speed was operating normally within the 10G range before dropping to 1G, rather than remaining at 1G, right?

I've escalated your case to our senior engineer. You can also share your information with them, and I'll also share your test results.

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#6
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-08-02 03:03:47

  @Joseph-TP 

 

Not sure i understand your question but I'll  give the latest example which might explain it ?.

Full disclosure in terms of changes made.

I have downgraded the firmware in both devices to the debug version advised by your engineer. V1_1.2.3_250623

I have disabled all overnight reboot and eco power options in both devices in case these were affecting or causing it.

It is my current observation that once the link is down speed any reboot, hard or soft, on the BE800 AP will usually not restore the speed.
I have seen exceptions to that but this seems to be the mostly reproducible norm. 

 

Last testing ~ 8PM last night working 10G SFP + link
First testing ~ 9AM  this morning working 10G SFP+ link
Soft reboot BE800 AP

SFP+ Link downgraded to 1G

Soft or hard reboot BE800 AP 
SFP+ Link remains downgraded to 1G 

Switch off both BE800

In sequence

Boot BE800 Main

Boot BE800  AP     

SFP+ link restores to 10G (usually)

The boot sequence logs for BE800 Main and BE800 AP only have one line for SFP but they do appear to be different.
No connection speed is reported in the logs at either 1G or 10G.    

 

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#7
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2025-08-04 03:17:45

Hi @StFual ,

Thanks for your update.

I noticed you're already following up with engineer via email. Please continue to communicate with the engineer promptly.
If you find a solution, please feel free to update this post and share it with other users.yes

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#8
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2 weeks ago

  @Joseph-TP 

 

I've posted this response  in two places because a similar question was in two different  places 

I'm now using  Beta 1.2.99 Build 20250806 rel.35019(4153) . This appears to have fixed my degraded speed problem on SFP+ links between BE800 and devices. 

I'm waiting on a full supported release.

Not sure what tp-link  did but looking at the log for the latest beta there appears to be much more SFP+ negotiation going on at boot. 
In my case any kind of power down (soft, hard, scheduled overnight) with Finisair SFP+ modules  was triggering the issue where the link speed would often degrade to 1Gbs.  I could usually fix by rebooting the BE800 Main  or unplugging and re-plugging the fiber link. It seemed to depend on which device came up first. 
It took me a while to realize it wasn't entirely random  because Tether doesn't display  link speed display and because while the BE800 device display can be configured to show smileys and snowflakes it doesn't show anything useful regarding link status.  As part of my own diagnostics  I swapped the Finisair and OM3  with Ampcom and OM5  and the problem became consistent after every reboot which made it much easier to prove. 

 

I've tested the Beta 1.2.99 Build 20250806 rel.35019(4153)  with Finisair and Ampcom SFP+ SR modules, with 10 Meters  OM5 and 15 Meters OM3 Fiber. All now appear to work OK.  

The Ampcom 10Gbs Copper Dac I started with still doesn't work in any reliable way - sometimes 1Gbs sometimes nothing. 

 

Based on my PC - BE800 and BE800 to BE800 SFP+  testing all this saved me about 100 µs (0.1ms)  latency testing over RJ45 - 10Gbe. 

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#9
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Re:BE800 SFP+ 10Ggb/s backlink downspeeds to 1Gb/s
2 weeks ago - last edited 2 weeks ago

  @StFual ,

Welcome back, and thanks for sharing.

 

For now, we recommend you continue using the beta firmware. For new firmware, please monitor the official website for updates or keep the auto-update button enabled on your router.

I think the engineer should have given you some advice on whether to use a DAC or not.

 

Engineers' suggestions are generally based on product performance, aiming to maximize product functionality and provide valuable guidance for improving user experience. Following their advice is a good choice.

 

Best Regards.

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#10
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