Problem : Slow upload speeds on specific combination of Synology router and TPLink Gigabit ethernet card

hadyp

hadyp

Disciple
Hi all,

I have a Synology RT2600ac router, and an ACT internet connection (300mbps up/down).
The internet connection type is setup as PPPoE.
I have a desktop with a TPLink Gigabit Ethernet PCIe card (TG 3468) and it is detected in Win 10 as a Realtek PCIe GbE Family Controller
In the desktop network connection properties, the link speed is 1000/1000 (Mbps) to the 2600ac.

I have noted that devices on wifi (my phone and laptop), get near symmetrical connection speeds with ~280-300 mbps upload and download speed.
When I connect my laptop to the 2600ac via a wired connection, I still get near symmetrical connection speeds with ~280-300 mbps upload and download speed.
However, when I connect the 2600ac to my desktop via a wired connection, the 2600ac reduces the upload speed to ~15-18 Mbps. Download speed remains at ~280-300Mbps.
The strange thing is, if I connect the incoming lan cable from the ACT router directly to my desktop (bypassing the 2600ac), I get a fully symmetrical connection speed again (~280-300 Mbps upload and download speed).
I have tried changing ports on the 2600ac, and also changing the LAN cable between the 2600ac-desktop, with no changes in the results. Confirmed that the LAN cable works fine for the laptop-2600ac connection.
There is no traffic control (upload/download speed limits or device prioritization) setup on the router.

So summary is -
a. 2600ac router is capable of 300mbps up and down in wireless and wired modes. (as seen in laptop results)
b. TPLink ethernet card on desktop can do 300mbps up and down (when connected directly to ACT's incoming lan cable, bypassing the 2600ac)
c. When TPLink ethernet card on desktop connects to 2600ac, I get full download throughput (280-300mbps) but upload speed is throttled (~20 mbps).
d. LAN cable ruled out as source of issue.

Can someone throw some light on what might be happening here? Any suggestions for fixing the upload speeds while using the Synology RT2600ac wired to the desktop?
 
Sounds like auto negotiation and/or jumbo frame related incompatibilities between the card and the router. What's the installed driver version for the LAN card?
 
I've installed the latest drivers as available on the TP-Link site - 'TG-3468_V4_200919_win10' which was released on 2020-10-29.
Wonder if using Realtek drivers directly would be a better bet?
 
Thank you for the suggestion.
Unfortunately, I updated the driver, and retested, with no change in the results from before. :(

ACT->2600ac->desktop = ~15mbps uploads, ~300mbps download speeds
ACT->desktop = ~300mbps upload and download.
 
@hadyp

That's a start; kindly share the default values of various driver parameters for the card. You can find them under Device Manager => Network Adapters => Realtek PCIe GbE Family Controller => (right click) => Properties => Advanced tab.
 
Big list here :)

Advanced EEE = Disabled
ARP Offload = Enabled
Auto Disable Ethernet = Disabled
Energy Efficent Ethernet = Disabled
Flow control= Rx & Tx enabled
Gigabit Lite=enabled
Green Ethernet=enabled
Interrupt Moderation=enabled
IPV4 Checksum Offload= Rx & Tx enabled
Jumbo Frame = disabled (is this the cause of the problem?)
Large Send Offload v2 (IPv4) = enabled
Large Send Offload v2 (IPv6) =enabled
Max number of RSS Queues = 4 queues
Network Address = Not present (????)
NS offload = Enabled
Power Saving Mode = Enabled
Priority & VLAN =Priority & VLAN enabled
Receive Buffers = 512
Receive Side Scaling = Enabled
Shutdown WAke-on-Lan = Enabled
Speed & Duplex = Auto Negotiation
TCP Checksum Offload (IPv4) = Rx & Tx enabled
TCP Checksum Offload (IPv6) = Rx & Tx enabled
Transmit Buffers =128
UDP Checksum Offload (IPv4) = Rx & Tx enabled
UDP Checksum Offload (IPv6) = Rx & Tx enabled
VLAN ID =0
Wake on Magic Packet = Enabled
Wake on magic packet when system... = Disabled
Wake on pattern match = Enabled
OWOL & Shutdown Link Speed = 10 mbps first
 
Please enable Jumbo Frame, restart and then monitor. Don't bother about the black Network Address field, as it's meant for putting a custom MAC.
 
So, there were two options in the Jumbo Frame - 4088 bytes and 9014 bytes.
Followed the process outlined for both these options (enable, restart, then run speedtest)

Unfortunately, no change in the results. Still seeing -
ACT->2600ac->desktop = ~15mbps uploads, ~300mbps download speeds
ACT->desktop = ~300mbps upload and download.

I updated the router firmware as well in another attempt to fix things, but no change with that either.
 
Now that's interesting.

Is there any kind of TTL settings set on the router under Network Center > Internet > Connection> ISP Settings? I remember you talked about having no traffic control, but is there anything unusual on Network Center > Traffic Control?
 
@ibose - thanks for your data point.
After your comment, I checked the laptop (which doesn't suffer from upload throttling on a wired connection), and it has an intel ethernet controller onboard.

@Titokhan : I checked, and nothing extra there in the ISP settings .
1625487107683.png

I also looked at the Network Center > Traffic Control, and nothing extra in there either. When I go into advanced, it asks me to turn it on (Traffic control ie)... so I guess its a secondary confirmation that it isn't active.

I will try this week to get an old router out of mothballs to try and see if that exhibits the same behaviour on the desktop. Maybe, just for the heck of it, put it as an intermediate step between the 2600ac and the desktop and see what happens then. Q is, of course, whether that old router supports gigabit ethernet or not... its pretty old.
The other option of course is to try and get hold of an Intel PCIe Ethernet card, but then the one I found on Amazon is nearly 5x the cost of the TPLink card that I have, so a bit hesitant to try that out.

Thanks a lot for your help and suggestions so far! Am open to any more suggestions if you have the time and enthusiasm for it :)
 
@ibose - I see a 1000/1000 mbps connection on the ethernet connection properties.
So, I'm guessing not a LAN problem per se?

@rockyo - Well, the throttling vanishes when i directly connect the ACT cable to my lan card... so i'm guessing its perhaps not the cause? But still, worth a try, will test it out over teh weekend. :)
 
Have you checked internet for any specific issue on this particular pcie card..
Screenshot_2021-07-07-23-51-24-48.jpg
found this...check if it solves something
 
Last edited:
@rockyo27 - I had hunted for some problems with this card but didn't come across anything that was a red flag so far.
Thanks for the tip above. I tried the option for the Large Send Offload (I only have Large Send Offload v2 for IPv4 and IPv6), and it didn't make any difference. I tried both the enabled and disabled modes.

The network connection properties (between 2600ac and desktop) shows 1.0 Gbps.
To check if I was actually being limited between the router and ethernet card, I tried transferring a single 2GB file to the SD card on the 2600ac, and the transfer occurred at a speed of ~80 mbps on average. I believe it was limited by the SD Card write speed, since the source drive was an SSD. There were intermittent peaks of ~200mbps.
All in all, it does seem to point to the ethernet link speed not being the root cause for the internet throttling.

I also got some feedback from Synology, and they asked me to turn off Safe Access - no difference in results there either.

I'll try resetting the router over the weekend. If that fails, then I guess the next option is to get an Intel PCIe ethernet card.
Any suggestions for where to order to it from? Found one on Amazon for abt ~4k, but wondering if there are better sources for one.
 
hadyp said:
@rockyo27 - I had hunted for some problems with this card but didn't come across anything that was a red flag so far.
Thanks for the tip above. I tried the option for the Large Send Offload (I only have Large Send Offload v2 for IPv4 and IPv6), and it didn't make any difference. I tried both the enabled and disabled modes.

The network connection properties (between 2600ac and desktop) shows 1.0 Gbps.
To check if I was actually being limited between the router and ethernet card, I tried transferring a single 2GB file to the SD card on the 2600ac, and the transfer occurred at a speed of ~80 mbps on average. I believe it was limited by the SD Card write speed, since the source drive was an SSD. There were intermittent peaks of ~200mbps.
All in all, it does seem to point to the ethernet link speed not being the root cause for the internet throttling.

I also got some feedback from Synology, and they asked me to turn off Safe Access - no difference in results there either.

I'll try resetting the router over the weekend. If that fails, then I guess the next option is to get an Intel PCIe ethernet card.
Any suggestions for where to order to it from? Found one on Amazon for abt ~4k, but wondering if there are better sources for one.
Click to expand...
Did you check with tp link support....they might help you with something
 
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