Asus rt-n66u strange behavior

[Fandroid]

Hi.

I've got a cable connection with modem synchronization 130/8. this weekend modem was replaced and since then I'm noticing the following strange behavior considering speed tests on speedtest.net to two nearby servers:
Old modem
Cable:
Server 1 - 125
Server 2 - 125
Wi-Fi 2.4
Server 1 - 105
Server 2 - 95
Wi-Fi 5
Server 1 - 110
Server 2 - 105
New modem
Cable:
Server 1 - 125
Server 2 - 125
Wi-Fi 2.4
Server 1 - 70
Server 2 - 90
Wi-Fi 5
Server 1 - 90
Server 2 - 120

Any explanation for this?

Observing speeds on Wi-Fi 2.4 I see a drop in speed from around 2/3 to the end of the test with new modem and frequent socket error when testing.

 

[Zirescu]

Does the new modem have built-in wifi enabled?

 

[Fandroid]

Both modems with built-in Wi-Fi disabled and lan port that connects to wan on Asus configured to bridge.

 

[Zirescu]

I wonder if new modem is throwing off more noise than the old modem. Are you using the same network cable between the router and the modem during each test? Cat5e or Cat6?. Do you have them both plugged into a UPS?

 

[Fandroid]

It's the same network cable. I think it's 5E but I'll confirm that. Link rate between modem and router is 1Gb. Both connected to same UPS. With cable connection to router I achieve full internet speed. What's on your mind that would affect only wireless speed?

 

[Fandroid]

Situation update after some more troubleshooting.

Not defining modem port that connects to Asus as a bridge restores speeds on Wi-Fi on both servers to normal up to 110mbps.

When the port of the modem is configured as a bridge even when doing nothing the link light flashes continuously. When not configured as a bridge the link light remains steady.

 

[Fandroid]

Is it possible to use ddns provided by Asus with Asus router connected to cable provider router without bridge mode?

 

[charlie2alpha]

Is it possible to use ddns provided by Asus with Asus router connected to cable provider router without bridge mode?

Unlikely since the client inside the ASUS router expects the router to have a public IP on its WAN interface.

 

[Fandroid]

Connected computer directly to cable provider modem/router in bridge mode. Incoming traffic is arp broadcast. Why does this traffic reduce Wi-Fi performance? What can I do to solve this problem?

 

[Zirescu]

When you're back in bridge mode is the client showing it's using the lowest data rate?

 

[Fandroid]

I don't know if I fully understand your question.
With bridge mode on or off link speeds remain the same. Real speeds are the same when connected by cable and reduced in bridge mode when Wi-Fi connected. This speed reduction is bigger in 2.4G than 5G.

 

[Fandroid]

Connected computer directly to cable provider modem/router in bridge mode. Incoming traffic is arp broadcast. Why does this traffic reduce Wi-Fi performance? What can I do to solve this problem?

Problem not solved yet. Any ideas?