LHG R + EC25-AF = 5Mbps MAX

RouterOS General
1

Hi all:

I’ve been really struggling to get an LHG-R up and going with Visible (Verizon) cell service to feed a remote customer. They aren’t looking for much; its a business that needs some remote monitoring and ability to run VoIP and some websites. In any case, there’s a cell tower that is line of site from up on their structure. But I haven’t even made it that far…

Microtik doesn’t offer any cell modems that include B13, which is where Verizon/Visible service is at. So I found the Quectel EC25-AF and acquired that. When I get it all installed and configured in the LHG-R (with latest firmware from Quectel and running RouterOS 7.7), it all comes up, but the max speed I can get is 5Mbps up and down. If I take the sim and EC25-AF out of the microtik device and install it in a USB mini-PCIe adapter, windows comes right up on cell data and gives me 60x20. During the speedtests on the Quectel EC25-AF, It does briefly surge above 5Mbps, then quickly comes back down.

I’ve only come up with two ideas to explain this:

  1. the interface or data pathways on the microtik board are only capable of 5Mbps; the initial surge is filling some buffer, but sustained data throughput is maxing some path out at 5Mbps.
  2. For some reason, the LHG-R is causing the data to appear to the cell provider as “hotspot” data rather than “native” data – there is a 5Mbps unlimited hotspot on this plan.

To test #2, I had a different Microtik device (LtAP) with a different Quectel card (RM500Q-GL). I put the SAME sim into that router, and achieved 40x15Mbps (and I think that was antenna differences). The LtAP started out with a factory reset and the default Quickset script applied, just like the LHG-R, which makes me suspect #2 isn’t happening…

I tried looking on Microtik’s website for a block diagram of how the different interfaces are attached to what on the micrporocessor like I can find for the LtAP, but no such diagram or technical information appears to be available for the LHG-R.

Can anyone shed some light on the cause of this slowdown and if there is any fix for it?

Thanks!
–Jim

2

Oh, I also just realized that the LtAP is running an older version of RouterOS. I think its still 7.x, but probably early 7.x, not 7.7 like the LHG-R. 7.8 is broke with Quectel cards, so I had to run 7.7.

3

I was able to do another test using an AT&T sim on the LHG-R with the same EC25-AF radio and found I saw full speed. So this tells me that for some reason, only on the LHG-R, traffic is being reported to the tower as hotspot traffic rather than “native” traffic. All other devices (including a different Microtik device) do not have this happening, so I am confused as to what is causing this.

4

Ok, so I found it…It was the TTL issue. There is a note on the Microtik docs that attempts to address this (https://help.mikrotik.com/docs/display/ROS/LTE#LTE-Avoidingtetheringspeedthrottling) but in my case, it didn’t work until I changed the TTL to 67. Don’t know why, but I now have the speed unlocked. Looking directly at a VZW tower with a Visible (new network) sim, I’m speedtesting 41 by 17 on the LHG R with the Quectel EC25!

Now I’m having issues where after ~5-10 minutes of being online, the link starts dropping and reconnecting anytime I try and use it (put traffic on the line). If I disable and re-enable the interface, it doesn’t do anything, but if I change my APN settings, it tends to work for another 5-10 minutes…

I’m wondering if that is bad hardware or bad firmware or ???

Thanks all!