ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers

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ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers

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ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-07-29 18:41:58 - last edited 2023-08-02 06:19:50

Hello folks,

 

So I'm having really slow download speeds with the ER8411 when using TP Link SFP+ TL-SM5310-T. For reference, the same happened with a Wiitek module as well. Here some details: 

 

ER8411 FW 1.1.0

SFP+ Module TL-SM5310-T 

Standalone 

 

Configuration: 

 

ISP Modem on Bridge (2.5g port) -----> ER8411 (SFP+) ----> PCs and Access points in the switch ports. 

 

Here the tests I've made: 

 

1)  Iperf from PC1 to PC2, on standard ports. Get full gigabit speed. Nothing wrong with the switch. 

 

2) iperf from PC1 to PC2, one in standard port and the other on SFP+ port 2 Lan, with the SM5310-T. Get full gigabit speed. Module and SFP+ port 2 working perfectly. 

 

3) ISP Modem, Bridge mode, connected to standard Wan port 4, PC1 connected to ER8411. Get full gigabit from ISP. So it doesn't seem to be anything with the ISP. 

 

4) ISP modem, Bridge mode, connected to SFP+ Port 1 with the module, PC1 connected to ER8411. Speed is throttled down to 200 - 300 mbps. 

 

So the only variable that I could see is the use of the SFP+ port as the iperf and other tests show the module and configuration are all working. 

 

I've tried both Flow Control enable and disabled; Both in the WAN SFP+ Port 1 and Switch ports. Nothing seems to resolve this issue. 

 

I know there's been some issues in the past related to this, but that was supposed to be fixed in the 1.0.2 fw. 

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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-07-31 03:23:22

Hi @ThiagoGuedes 

Thanks for posting in our business forum.

Some facts before you start other tests.

1. ER8411 only supports 1Gb and 10Gbps SFP speed.

2. SFP+ is easily affected by the temperature. Eventually, it causes problems to the speed. Can you confirm that this SFP+ is not super hot during the speed test run?

If you have two modules running with a heavy load, can you remove one and test again?

You can also set the port speed of the SFP to 10Gbps. And test this again.

 

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting Manual ★ ☚ (Disclaimer: Short links are used above solely for guidance to TP-Link subdomains and are safe and tracker-free. Exercise caution with short links from non-official members on forums. We are not liable for external content or damage from non-official members' link use.)
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-07-31 10:21:44 - last edited 2023-08-02 06:19:50

Hi  @Clive_A 

 

Thanks for replying. Onto your comments: 

 

1.: Yeah, I'm aware. From what I see, the SFP+ module has negotiated at 10gb on one side and 2.5Gbs on the other so it seems to be working as expected. I know this because when I change the ISP Router to Gateway mode, I can see it's negotiated 2500 on its side. 

 

2.: I've got only one module, it's currently in Port-1. It's not a heavy load really, but I'm monitoring the temps. CPU is at 57, PCB at 54. Typical temperature in the module when checked at DDM is 65-70 and I've never seen it past 70. 

 

Surprisingly now, sometime the whole thing works as expected. I was running some tests yesterday, and after plugging and un-plugging between WAN Ports 1 and 4, I managed to get it to output the full speed. However, if for whatever reason I need to reboot the ISP Router (which is annoyingly frequently) it's back to reduced speeds for a while. 

 

Thanks,

 

T

 

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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-01 01:02:10

Hi @ThiagoGuedes 

The temp looks good to me. Nothing to worry about.

If it works, the link speed looks good, you can leave it alone. Don't change any other parameters. Changing the link speed could affect the speed sometimes. Set to the right link speed will make the SFP+ work perfectly.

 

If you run into any other trouble, let me know. I'll leave it to you.

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting Manual ★ ☚ (Disclaimer: Short links are used above solely for guidance to TP-Link subdomains and are safe and tracker-free. Exercise caution with short links from non-official members on forums. We are not liable for external content or damage from non-official members' link use.)
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-01 17:13:28

 Hi  @Clive_A,

 

Thank you. Yes, I can confirm that at least for now, this is working - I'm just not sure what's going to happen when I need to reboot the ISP modem. 

 

In cany case, do we have any troubleshooting tools we could use? I checked the logs, couldn't really see anything especificaly. For now, Flow Control is also on on the WAN port so I'm not going to change it but I know there's been some discussion around it in the past. 

 

Best,

 

T

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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-01 21:04:51 - last edited 2023-08-01 21:09:19

Well, spoke too soon. I had to reboot my ISP modem today (having some other issues with Rogers. Lo and behold, I'm back to slow speeds again. This makes no sense to be honest :/

 

Edit:

 

I've found something interesting. When I plug the network cable in the SFP+ port with the transceiver, my CPU skyrockets. When I switch it back to Port-4, it goes down again. But regardless of going down, speed will still be capped at 280 - 300. 

 

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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-02 02:18:53

Hi @ThiagoGuedes 

About the CPU usage, without a wire connected to the module, is it this high usage? If with a wire? What are the results? Is it constantly getting sky-high CPU usage?

 

For the modem problem, can you confirm when the speed is low/incorrect, is the link speed negotiate right? Because this seems to be erratic. Weird enough that this only happens to SFP+ but with the Ethernet to the ER8411, it's all normal speed? Which does not seem to be an ISP issue either.

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting Manual ★ ☚ (Disclaimer: Short links are used above solely for guidance to TP-Link subdomains and are safe and tracker-free. Exercise caution with short links from non-official members on forums. We are not liable for external content or damage from non-official members' link use.)
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-02 03:53:27

 

I'm having an equal issue.

 

I have a 10G internet connection. Router shows 10G connection. But the fastest I get is ~400MBs.

 

Connect direct, I can get speed tests of ~5000 to 7000 depending on speed test site.

 

I ordered a 2nd ER8411 router to test. I'll test it this week.  Also got 4 SPF+ 10G modules to test too.  (I'll keep it as a spare)

 

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#8
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-02 10:54:58

Hi  @Clive_A 

 

I monitored more closely, and it's a temporary spike whenever I change either to SFP+ port 1 or Wan Port 4. It drops quickly and the speed remains low so not sure if it's actually related. 

 

ISP modem on the other side is in Bridge mode so I can't access it to confirm the link speed there. However, when connected to the gigabit wan port it gives me amber led while when connected to the module it gives green led. This is consistent with the tests I've performed when I had it in Gateway mode temporarily running the tests. 

 

Speeds on Wan 1gbs Port 4 are normal. All I'm doing is switching Wan connection from SFP to Port 4 giga and everything works at giga speeds. I've tested the module and I know it can negotiate 2.5 so the only variable is the actual SFP+ slot that's working weirdly. 

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#9
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-02 10:55:33
Please keep us posted if you find anything! I'm trying to troubleshoot some more.
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#10
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-02 21:41:36

Folks,

 

I may be on to something. I managed to get full speeds when using SFP+ port. Following these exact steps: 

 

1) Turn off Router and ISP Modem 

2) Turn on Router - wait for it to come up completely (on the XB7, it's a solid white line). 

3) Connect the cable from the router 2.5 port to SFP+ port with the ER8411 still off. 

4) Turn on the ER8411. 

 

And voila, I got full speeds. 

 

My two cents is that something in the auto-negotiation and/or flow control breaks if the link goes down. 

 

Is there any way we can ssh into the router and check what's the wan port status there? It *may* be that the interface is showing Flow Control is on, but it's actually not on.

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