Low download speed on R3 (130–176 Mbps) despite direct connection giving 350–450 Mbps

[mrmesho]

Hello everyone,

 

I need help with a strange speed issue on my Netduma R3.

 

Setup:

 

· ISP router: Huawei H155‑381 (5G) — connected via Ethernet cable

· Netduma R3 in DMZ (R3’s WAN IP is in Huawei’s DMZ)

· PC wired directly to R3

 

Symptoms:

 

· When the PC is connected directly to the Huawei router (bypassing R3), I get 350–450 Mbps download.

· When the PC is connected through the R3, I only get 130–176 Mbps download.

· Ping is stable, Geo‑Filter works, but the download speed is capped.

 

What I have already tried (following forum advice):

 

· IPv6 disabled on both LAN and WAN of R3

· Congestion Control set to 70% / 70% and also tried 100% / 100%

· Congestion Control Mode = Always On

· Speedtest Bypass = OFF

· Tried UPnP on / off (currently off)

· Tried different Ethernet cables (CAT5e and CAT6)

· Tested with SmartBOOST enabled / disabled

· Confirmed that the WAN IP in Huawei’s DMZ is correct

· Factory reset of R3 and reconfigured

 

Nothing changed — the speed remains around 130–176 Mbps through R3.

 

Note:

I play Warzone competitively, so stable low latency is important. The speed cap itself does not affect gameplay, but I would like to understand why the router is limiting the throughput so much. Could this be a known bug, or am I missing a setting?

 

Thank you for any suggestions.

[Netduma Fraser]

Where are you testing the speeds specifically and is this over WiFi or ethernet? You'd definitely want Speed Test Bypass enabled to see the full speeds. Have you entered your expected speeds into the router?

[mrmesho]

Thank you for the suggestions.

 

I have tried the following:

 

· Enabled Speed Test Bypass in Ping Optimizer > Advanced.

· Entered my expected speeds (450 Mbps download) in Settings > Speed Test > Advanced.

 

However, I’m still seeing the same issue:

 

· When my PC is connected directly to the Huawei 5G router, I get 350–450 Mbps.

· When connected through the Netduma R3 (with DMZ setup and IPv6 disabled), I get only 130–176 Mbps.

 

I am testing via Ethernet, not Wi-Fi.

IPv6 is disabled on both LAN and WAN.

UPnP is disabled.

Congestion Control is set to 100% with “Always On,” and SmartBOOST is disabled.

 

Speed Test Bypass didn’t change anything — the speed remains low through the R3.

 

Could this be a hardware issue with the WAN port, or is there something else I should check?

 

Thank you for your support.

[Netduma Fraser]

Where are you testing the speeds specifically? Are ALL devices connected to the R3 or do you still have some connected to the Huawei? It's very unlikely to be hardware.