Poor 5GHz performance on ArcherC1900 v1

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Poor 5GHz performance on ArcherC1900 v1

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Poor 5GHz performance on ArcherC1900 v1
Poor 5GHz performance on ArcherC1900 v1
2020-12-18 13:45:15
Model: Archer C1900  
Hardware Version: V1
Firmware Version: 3.17.0 Build 20151009 Rel.61423n

I have two ArcherC1900 v1 units with the new one connected to the old one via LAN cable. The new one has similar performance on the 2.4GHz band as the old one but for the 5GHz band it seems to connect but have almost no data transfer.

 

My ISP link is a 100Mbit link and on the 5GHz band of the old unit I am getting excellent results (https://www.speedtest.net/result/i/4315730236). For the new unit, the results on the 5GHz band are terrible (https://www.speedtest.net/result/i/4315728901). These tests were conducted within seconds of each other and from within the same room as each router.

 

I have also tried swapping the routers making the new one the one connected to the Internet and the old one the one connected to the new one via LAN. The results are the same. I did a reset to factory one the new one but the results were still poor. I also tried unscrewing and swapping the three physical antennas but nothing seems to get the 5GHz band on the new one to work well.

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Re:Poor 5GHz performance on ArcherC1900 v1
2020-12-25 06:17:06

@HoundTT 

 

Have you tried to modify the 5G wireless settings on the two C1900? Ensure they are using different 5G channels, let's say, Router A use channel 36, then choose channel 44 on Router B to give it a go.

 

BTW, ensure both routers are running the latest firmware.

 

It is also suggested changing the 2nd router into Access Point mode, then monitor if there is any difference:

https://youtu.be/Cg_gGECGLiY

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Re:Poor 5GHz performance on ArcherC1900 v1
2020-12-25 13:01:00 - last edited 2020-12-25 13:07:29

@Kevin_Z, thanks for your response. I've actually been working with TP-Link support since I posted this. In short, yes I've ensured the routers are using different 5GHz channels and are both running the latest firmware to the best of my knowledge. The ArcherC1900 does not have an AP mode configuration but they are connected using your recommended setup (https://www.tp-link.com/en/support/faq/417/). As mentioned above, having the new unit in either router or AP mode makes no difference to the 5GHz performance. I've also run the new unit in standalone router mode without the old one connected with no change.

 

For the longer answer, I previously conducted troubleshooting using the FAQ (https://www.tp-link.com/en/support/faq/2170/) and determined the issue to be case 2 and supplied the relevant details. The wireless clients connect with a strong signal level (e.g. for a 802.11n client I connect with the following - Channel 149 (5GHz, 40 MHz), RSSI: -68dBm, Noise: -95dBm, Tx Rate: 243 Mbps, MCS Index: 20, NSS: 0). The poor performance is equally apparent in a variety of other wireless clients (Windows, macOS, iOS, Android).

 

What is strange to me is that while connected I can get small data transfers through like basic pings, most DNS lookups and even text messages on WhatsApp desktop on the router but once I try data transfers of substance (WhatsApp media messages, iMessages, e-mail, web pages, LAN file transfers) it fails. I sometimes wonder if it's an invisible traffic throttle in the router software or if it's a hardware issue but I have no way of doing any kind of debugs or advanced diagnosis to find out. I have done factory resets on the unit but that's about all I can check. Hopefully TP-Link support will shed some light on it when they get back to me.

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Re:Poor 5GHz performance on ArcherC1900 v1
2020-12-28 01:48:21

@HoundTT 

 

Thanks for all the detailed info. It seems you have some CPEs in the network, and the case has been followed up via the support email, it is suggested to follow this up with the support engineers, they will try to help you out.

Nice to Meet You in Our TP-Link Community. Check Out the Latest Posts: Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN Archer GE550 - BE9300 Tri-Band Wi-Fi 7 Gaming Router EasyMesh Is Available When Wi-Fi Routers Work in AP Mode as A Controller. Archer AX90 New Firmware Added Support for EasyMesh and Ethernet Backhaul If you found a post or response helpful, please click Helpful (arrow pointing upward icon). If you are the author of a topic, remember to mark a helpful reply as the "Recommended Solution" (star icon) so that others can benefit from it.
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