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

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

41 Reply
Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-18 19:01:16

  Hi @thePrince 

I'm doing a few more tests. 

 

I've changed SFP+ Port 2 to be Wan (for whatever reason, Port1 won't show up for me to look in the switch). But SFP+ Port 2 shows. 

 

 

Then I went to Switch, and enabled Flow Control on all ports, including Port 2 which is now WAN: 

 

 

 

Here the status of each: 

 

 

And now the interesting part. Even after having cleared the statistics and ran a bunch of tests, I see no PAUSE frames been sent or received. And the speed is still pretty bad. 

 

 

 

 

 

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#33
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-18 19:16:41

  @ThiagoGuedes 

 

Port 1 is WAN only, it's not connected to the internal switching interface, which is why it doesn't come up.  Also I don't think PAUSE frames sent over the WAN interface show up on that counter, only to or from LAN.

 

I ran this experiment as well, unfortunately it doesn't rule out either scenario.

 

1)  This could mean that the flow control is not working for traffic originating from the WAN entering the LAN, so no PAUSE frames generated.

 

2) The ingress buffer for the modem -> router link is  overflowing, therefore dropping packets, in which case you wouldn't have seen PAUSE frames anyway.

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#34
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-18 19:29:17

  @thePrince 

 

Shoot :/ 

 

Running out of options. 

 

The only other thing I managed to find, is that there were some people with similar issues with Uniquiti routers and this modem. Apparently, there's one media converter that does the trick, but it would need to be imported from Fs com.  

 

But again it's a shot in the dark. 

 

 

 

 

 

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#35
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-18 19:53:42

  @ThiagoGuedes 

 

Might be worth checking this out, but I give it 50/50 chance it won't.

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#36
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-26 07:47:28

  @thePrince 

 There seems to be something wrong with this 1.10 firmware. My ER8411 WAN port stopped working after update, now running only secondary WAN at port 3. SFP+ module is detected, but status of the connection is Offline all the time.

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#37
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-26 12:44:33

  @Enhancer 

 

I had issues updating to 1.10, my router stopped responding to all traffic and had to be factory reset after 24 hours on the update, and refuses to be readopted to my omada controller..

 

I would also suggest trying a factory reset.

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#38
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-27 07:04:53

  @ThiagoGuedes 


I have some good news, I think I may have some additional information on the issue that may at least lead us a to a root cause, and possibly a solution.  I was able to get shell access to the router tonight, its more hidden than it used to be...

 

But in the logs I noticed this...

 

[773032.229282] mvpp2 f4000000.ethernet dpdk3: Link is Down
[773032.238842] mvpp2 f4000000.ethernet dpdk3: Link is Up - 2.5Gbps/Full - flow control off
[773141.152968] mvpp2 f4000000.ethernet dpdk1: Link is Down
[773184.229237] mvpp2 f4000000.ethernet dpdk1: Link is Up - 10Gbps/Full - flow control rx/tx
[773184.237474] mvpp2 f4000000.ethernet kern1: Link is Up - 2.5Gbps/Full - flow control off

 

First interesting thing is that the router's OS is actually aware the link is operating at 2.5Gbps.

 

Next, notice the first set of logs was me enabling flow control, that disabled the link and re-enabled it... notice how its still reporting to be off.

 

Then I hotplugged the SFP transceiver, and then connected rj45 cable.  Flow control is enabled with just the transceiver plugged in, but disabled once the link is re-established.

 

So the the ball is back in TPLink's court, there is an issue with the router fw that causes the flow control to get disabled in this state.  I suspect its that its not native link rate (1G/10G), so its blocking it from getting enabled.

 

Based on this, would really like for someone from TPLink to weigh in here, why is flow control not being enabled here?

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#39
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-27 14:24:15

Hi  @thePrince, (and @Clive_A for awareness, as he truly tried to help). 

 

That's a good find. I mentioned to you before, I was pretty sure there was something wrong with Flow Control as I don't think the protocol wouldn't be respected at the modem level. 

 

I honestly gave up and returned mine, in most part due to the horrible customer service. I was tired of answering the same questions, tired of asking for them to try to reproduce the issue on their side, tired of asking to SPEAK to someone and been told they could only chat. In more than 20 years of IT I've never seen something like that. 

 

I hope they actually fix this issue with a coming firmware because the router is pretty good overall. Unfortunately I can't really depend on this kind of support from the manufacturer. 

 

I'll keep an eye on this topic so please do let us know if you find anything else - I'll be curious to know the end of the story. 

 

Thanks,

 

T. 

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#40
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-27 14:36:33 - last edited 2023-08-27 15:54:44

  @ThiagoGuedes 

 

Yeah understandable.  Had I known back when I bought it that only the WAN would have issues with flow control I would have returned it, since I had just tested from 10G LAN to 1G LAN was fine at that time.

 

At this point there isn't much more I can do because I have no idea what kernel source was used to compile the FW, and it looks like there has been lots of contributions to the mvpp2 driver (Marvell is the manufacturer for the chip in my transceiver) recently.  From what I can see there shouldn't be any barriers to it getting enabled other than setting auto negotiation and Rx/Tx flow control itself.

 

Hoping this week someone from TPLink can actually take a look and at least provide some advice. I'd be fine with a hacky fix since it's a niche use case.

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#41
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Re:ER8411 - Slow Speed in SFP+ Port w/ TPLink Transceivers
2023-08-27 15:06:15

Hi, @thePrince 

 

And I can tell you that there is a workaround for sure, because there were two instances where I got full speeds but unfortunately I had to reboot my modem and lost it. 

 

Initially I thought it had to do with the order the equipments were turned on, but it didn't work. Then I tried to see if booting up the 8411 with the module and network cable attached would work but it didn't. 

 

So there should be a simple patchy way to get it done. 

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#42
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