Question

I have installed a RUT240 device in Passthrough mode as a failover WAN in the company's main router.

When i tested the failover by disabling the main WAN most computers lost internet connection with Chrome throwing dns errors and really slow or inconssistent access to the internet.

When the employees went home i then tested the failover again and the internet was slow (high latency) with 16Mbs.

So my question is: given the large amount of 20 users, do you think the problem is the poor signal reception (which i can try to resolve with an external antenna) or is the hardware processing power that is not capable of handiling so many internet requests?

This is my first experience with such a large environment of users and also with teltonika 4G routers.

Thanks 4 sharing your thoughts

Answer 1

Hello,

Depending on your employers needs, the reason may simply be low bandwidth of RUT240. It has an LTE Cat 4 modem, which theoretically can achieve up to 150 Mbps downlink speeds, but real performance is likely to be significantly lower and thus, even 16Mbps as you have received. Sharing it among 20 hosts does not leave much bandwidth for separate users. 

Could you login to the router's WebUI, navigate to System -> Network -> Mobile and post values of RSSI, RSRQ, RSRP, and SINR?

What firmware version your RUT240 has installed?

Best regards,

Comments

Hi, so I made further tests:

Internal antennas high spot:

Signal -66

LTE B20

RSRP -102

RSRQ -12

SINR 7

Speedtest 24/11

External Antenna

Signal -66/-73

LTE forced into B1

RSRP -101

RSRQ -7/-12

SINR 17/20

Speedtest 48/21

with this latest setup I had 3 pc running YouTube 480p and 3 actual users. Memory was 80% and cpu between 75% and 90%. When the failover happened, some computers had no internet (dns probe finished) but when I went back again to troubleshoot they were already with internet.

so it seems that dns takes time to propagate to all machines , will take further testings by the end of the month as right now they are at a peak of work and i can’t disrupt their work.

if with almos no traffic CPU was struggling and RAM was almos maxed out, in the end I will not get away without new hardware. New RUTX have all the same cpu and ram, I wonder if the Modem Category is making the difference in my case.

Anyone with similar setup/experience would much appreciate your input.

Thanks

---

Hello,

In terms of CPU and RAM usage, there are rapid changes over short periods of time, and data sampling for WebUI representation may not provide representative results about actual CPU load.

To get a better picture about CPU and memory usage, I would suggest to install htop. This is dome over SSH with the following commands:

• opkg update
• opkg htop

For your DNS propagation issue, you can add additional option to dnsmasq configuration, to use all available DNS server, rather that based on the currently used interface. The reply from the server which answers first will be returned to the original requester. To do this access router over SSH again, enter the command below:

• vi /etc/config/dhcp

Press letter i to enable editing and add the following option at the bottom of dnsmasq configuration:

• option allservers '1'

For example:

Once done press Esc, then enter :wq and press Enter. Then execute the following command:

• /etc/init.d/network restart

"I wonder if the Modem Category is making the difference in my case."

It should. The fact that Cat 6 modem RUTX11 comes equipped with support two band carrier aggregation should already provide an improvement. The modem is also capable to maintain connection under worse signal conditions and achieves better speeds in general. Though, if your goal is still 20 active users, the bandwidth achieved may still not be sufficient to provide acceptable performance for everyone.

Best regards,