RT-AX88U LAGG WAN - LAN Throughput Issue

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DexterII

Occasional Visitor
Hi all,

I've been trying to maximize my ISP's bandwidth to my main computer. I'm currently subscribed to Comcast's Gigabit tier internet (1200/40). I have Arris SB8200 with an Asus RT-AX88U running stock firmware ver 3.0.0.4.386_44266.

I have LAG enabled on my SB8200 and WAN LAG enabled on the router. The router indicates a 2 Gbps connection on the WAN side.

I have a Macbook Pro with two Thunderbolt -> Gigabit Ethernet adapters, and I enabled LAN LAG as well. The Mac is indicating a successful bond to the router.

I run simple speed tests using Ookla's speed testing website. Most of the time it will average 700-800 Mbps. I check in the traffic analyzer and it shows a balanced load between the two bonded LAN ports avg. ~50MB/sec per port.

I have QoS disabled.

This didn't seem right. As if I disconnect one of the LAN ports it will test to 940 Mbps.

Now on occasion, especially if I keep running the speed test over and over, it will start avg. 800-950 Mbps. One time it even hit 1030 Mbps. But it typically avgs. the above stated amount.

Out of a hunch, I connected my computer directly up to the modem and it tested almost 1200 Mbps consistently. So it's obviously the router bottlenecking.

Anyone have any suggestions or something to check for?

Thanks!
 

L&LD

Part of the Furniture
LAG for a single client can only be the maximum of a single connection (I'll be corrected (again) if I'm wrong here).

Your ISP may be guaranteeing that 1.2Gbps download speed with more than a single client being tested, simultaneously.

Which ports on the RT-AX88U are you using, specifically?

Does the SB8200 have 2.5GbE ports? Are you able to buy an RT-AX86U instead (and sell the RT-AX88U)?
 

DexterII

Occasional Visitor
LAG for a single client can only be the maximum of a single connection (I'll be corrected (again) if I'm wrong here).

Your ISP may be guaranteeing that 1.2Gbps download speed with more than a single client being tested, simultaneously.

Which ports on the RT-AX88U are you using, specifically?

Does the SB8200 have 2.5GbE ports? Are you able to buy an RT-AX86U instead (and sell the RT-AX88U)?
The tests performed are done with multiple servers (streams) simultaneously.

I do hit the roughly 1200 Mbps (1170 Mbps was the max on one test) when directly connected to the modem. So I know the speed is possible.

I have the SB8200 connected to the WAN + LAN Port 4.

I have the dual ethernet computer connect to LAN Port 1 + LAN Port 2.

Forgot to mention I'm using CAT 6 and CAT 6A wires.

The SB8200 only have two 1GbE ports. I purchased my RT-AX88U a few years ago, so it's past it's return period.
 

L&LD

Part of the Furniture
Possibly test using WAN + LAN 4 and your computer connected to LAN 2 + LAN 3 (or L2 + L4, or L3 + L4).

Also, try testing with other websites too (such as fast.com, etc.) as that can make a difference, depending on who your ISP provider is.
 

DexterII

Occasional Visitor
Possibly test using WAN + LAN 4 and your computer connected to LAN 2 + LAN 3 (or L2 + L4, or L3 + L4).

Also, try testing with other websites too (such as fast.com, etc.) as that can make a difference, depending on who your ISP provider is.
I get where you're coming from. But it doesn't appear the RT-AX88U supports LAN side LAG on any other ports other than port 1+2.
 

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DexterII

Occasional Visitor
OK - So I updated to Merlin 386.3_2. I'm getting different results but not sure if now I have new options.

It seems the balancing of the bandwidth across the two ethernets has changed. I am speed testing an avg 860-920 now but I noticed it's only using LAN 2 for download and LAN 1 + 2 for upload testing.

It would almost appear very little downstream data is being sent using LAN 1 now. Even with simple web browsing. Just like my prior tests, if only one port is mainly used I would get higher speed results. It's when it was 50/50 across the two links the speed was worse.

It also appears to be the router controlling this balancing because I tried swapping the wires from the computer to the router (L1 to L2, L2 to L1) and the download continues to be on L2.

Ran a couple speed tests:

L1 - Total download: 2.28 MB
L1 - Total Upload: 56.11 MB
L1 - Max download: 0.23 MB/s

L2 - Total download: 1811.75 MB
L2 - Total Upload: 45.05 MB
L2 - Max download: 123.52 MB/s
 
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