LAN file transfer chokes wifi connection

[Fishy23]

Hi all, thank for looking at my post.

I have a problem with my onboard wifi adapter and I was hoping to find some settings that I could experiment with.

I have a typical home office setup - broadband connection -> broadband modem -> router -> A PC, laptops, NAS, playstation, tvs, devices. From the PC, whenever I have a file transfer going (say from the PC to the NAS or to a laptop at about 45MB/s) or windows backup file copy going the connection gets choked. My internet access goes from excellent to patchy to "disconnected" over about the first 20 secs of the transfer, VPNs disconnect, I can't access the web logins for my NAS or router on the home network, and so on. The file transfer completely takes over, if paused or completed everything is restored, if restarted it all stops working again.

I have tried updating to the latest drivers, fresh install of Win10x64, file transfer from/to other computers and combinations all work perfectly without choking, using the ethernet adapter on the problem PC also works perfectly and doesn't affect other network services. When the PCs wifi is choked all other network traffic is normal and not affected, only the PC's connection to network services. It's quite frustrating and it seems to come down to the onboard wifi adapter and/or how Windows has it configured as I believe I've excluded everything else.

Details about the setup:
Windows 10 Home x64 - updated to latest version
MSI B450 GAMING PRO CARBON Version 1.1, BIOS 1.B0
Ryzen 3600
32GB GEIL memory
ADATA SX8200PNP (OS drive)
1 SATA BD-RW
RTX 2080 Super, BIOS NV372MH.401
D-LINK DIR-890L Router
Synology DS1815+ NAS
50mb/s broadband connection which tests up to 43mb/s

Any requests for further information or suggestions would be much appreciated.

Cheers,
Fishy23

[icecream-guy]

QoS configuration on Wifi comes to mind,
Also have ou looked into the Winds TCP Windowing?
you might want to run Wireshark during congestion to get an idea of what is going on at the network layer,
TCP out of order, (packets dropped) and TCP retransmission packets are typically the cause of congestion.

[Fishy23]

Thanks so much! Your thoughts are much appreciated.

I've started with running wireshark and have a capture file. It involves starting a 10 min file transfer and then trying to log on to the NAS and router web interfaces and refreshing several times to try to get it to work (as well as other general web traffic). As I'm not previously familiar with wireshark I can see there are different colour bands. Blue, yellow, red, grey, black.

I see TCP retransmission, TCP ACKed unseen segment and previous segment not captured, RST, ACK, time-to-live exceeded, TCP Dup ACK, and TCP Fast Retransmission messages.

Is the capture file safe to upload?

Again, much appreciated as this has been a frustrating issue for me.

[deanwebb]

Typically, we encourage loading screen captures with IP addresses blanked out for security purposes.

Question - is the D-Link in charge of your wi-fi?

[Fishy23]

Thanks so much.

When I tried to clean up the traffic and run it again, all the black zones went away on wireshark, now only blue and yellow.

From what I can see, TCP Windowing is changing the max packet size is it? I have done this on other PCs in the past. I'm happy to figure out how to change it myself but any suggestions about what numbers I should be trying?

Regarding QOS, here's the router interface and options available as a capture. I've tried it turned off and on previously but happy to try again. The D-Link is in charge of the wireless.

[Fishy23]

I should probably also just say, I had the same set up with my old PC and never experienced a choke. I then built a new computer and picked out one with an onboard wifi adapter. I started using the onboard wifi adapter and haven't been able to file transfer and access the network at the same time since. When I set it up and tested it, I felt the speeds and reliability of the wifi connection was very good.

I haven't tried it with a different router but no other wifi adapter or device has issues.

[Dieselboy]

That looks like a beefy DLink.

My guess is that the CPU on the DLink is going high while trying to route from wifi > LAN for the NAS. Is there any way to check CPU usage on the DLink? Then run the test again?

Also, are you using 2.4 or 5GHz wifi? If you're using 2.4GHz can you confirm you're using 20MHz-wide channel?

I checked the DLink model and it apparently supports 3GB wifi throughput. My thought is, your PC is getting a high speed on the wifi and it's choking the CPU of the DLink. 45mb/s file transfer speed is not that high. Spinning HDD's get around 80MB/s as seen by Windows over USB. Do you know what the NAS is capable of?

[Fishy23]

Excellent, thank you so much!

There is only a statistics page in the router interface with tabs - Internet, LAN, Wifi 2.4, Wifi 5. No CPU.

However there's also a syslog function that can be directed to an IP address:
"On-board diagnostics run continually in the background to monitor the health of your router. The results are recorded in the system log if it is enabled. This info can be used to diagnose common problems or help Customer Support resolve issues more quickly."

I'm just working out how to use the NAS as a syslog server to see if CPU data is included in the log.

I can confirm it's 5GHz wifi that I'm connected to. Windows says between 433 and 780 Mbps (mostly 650) on the wifi connection properties ("Status"). That speed does jump around more than I expected it to once I watch it for a while.

The NAS setup is JBOD. I'll post the stats below. I'll shut down everything background and get a speed from the SSD's to the NAS over the wifi. However, I tried a file transfer to 2 different laptops previously and it still choked the connection fyi.

Thanks again for all your help!

[Fishy23]

Synology DS1815+ Specifications:
Hardware
CPU Intel Atom C2538 Quad Core 2.4GHz
Hardware Encryption Engine Yes (AES-NI)
Floating Point Yes
RAM Size DDR3 2 GB - has been expanded to 16gb
Internal HDD/SSD 3.5" or 2.5" SATA(II) X 8 (hard drives not included)
Max Internal Capacity 48 TB (6 TB HDD X (The actual capacity will differ according to volume types)
Hot Swappable HDD Yes
External Ports USB 3.0 ports X 4, eSATA X 2
Size (HxWxD) 157 x 340 x 233 mm
Weight 5.29 kg
LAN Gigabit X 4
Wake on LAN/WAN Yes
Wireless Support Yes (wireless dongles not included)
AC Input Power Voltage 100V to 240V
Power Frequency 50 Hz to 60 Hz, Single Phase
Operating Temperature 5°C to 35°C (40°F to 95°F)
Storage Temperature -20°C to 60°C (-5°F to 140°F)
Relative Humidity 5% to 95% RH

General
Networking Protocols CIFS, AFP, NFS, FTP, WebDAV, CalDAV, iSCSI, Telnet, SSH, SNMP, VPN (PPTP, OpenVPN™, L2TP)
File System Internal: EXT4
External: EXT4, EXT3, FAT, NTFS, HFS+
Storage Management
Max File System Size: 108 TB, Max Internal Volume #: 512, Max iSCSI Target #: 32, Max iSCSI LUN#: 256;
Raid Clone/Snapshot support; Supported RAID Type: Synology Hybrid RAID, Basic, JBOD, RAID 0, RAID 1,
RAID 5, RAID 6, RAID 10; Synology Expansion Unit Support : DX513, DX213
File Sharing Capability Max User Account: 2048, Max Group: 256, Max Shared Folder: 512, Max Concurrent CIFS/AFP/FTP
Connections: 512
Privilege Windows Access Control List (ACL)
Directory Service Windows AD Integration: Domain Users login via Samba (CIFS)/AFP/FTP/File Station, LDAP Integration
Virtualization VMware vSphere 5, Microsoft Hyper-V, Citrix Ready
Security FTP over SSL/TLS, IP Auto-Block, Firewall, Encrypted Network Backup over Rsync, HTTPS Connection
Utilities Synology Assistant, Cloud Station, Evidence Integrity Authenticator
Supported Clients Windows XP onward, Mac OS X 10.5 onward, Ubuntu 9.04 onward
Supported Browsers Chrome®, Firefox® Internet Explorer®: 8 or onward, Safari® 5 or onward, Safari (iOS 5 or later on iPad®),
Chrome (Android™ 4.0 on tablets)

[deanwebb]

See if your PC wifi drivers can be updated. I've often seen updating drivers as a solution for wifi issues.