Latency of Peplink eSIM roaming on T-Mobile versus direct T-Mobile SIM

Everything Else Wireless Carrier Troubleshooting
1

I picked up a T-Mobile 10 gig/month hotspot SIM thinking it would be a better value than the Peplink eSIM roaming onto T-Mobile’s network.

But to my surprise, they have different latency. The Peplink eSIM is stable with occasional spikes but the direct T-Mobile SIM oscillates between ~50ms and ~280ms every few seconds. And the latency weirdness seems tied to the SIM. It behaves that way plugged directly into a B One 5G or the TCL LINKPORT USB dongle it came with.

Any guesses about why T-Mobile’s own SIM has oscillating latency?

2

Did you ordered Static IP? Usually such problem only with static IP.

3

No static IP. Just a basic dongle + SIM.

4

Sounds like it might be connected via NSA and randomly switching between 5g and 4g bands for download. Have you tried selecting 5g only on the Peplink and forcing it to use SA mode?

5

So near as I can tell, it seems like there is some interference on the n25 band? It stays on that but the SINR fluctuates between high 20s and 9 db. Is that normal? The B One 5G is stationary. And the Peplink eSIM seems to prefer n41. So that could explain the difference.

6

Maybe try disabling n25 and see if it connects to n41 like the other one?

7

Seems that both n25 and n41 have the problem. I tried turning off 5G entirely and that seems to have fixed the problem. Weird.