TX/RX packet errors via lte rndis0 (usb)

junbr0 · Wed Sep 04, 2024 12:32 pm

mikrotik 951Ui (under android arm dev) connection through usb (rndis0) to android LTE device
android arm dev ( rooted magisk with termux)
ifconfig on lte android arm device

rndis0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.42.129  netmask 255.255.255.0  broadcast 192.168.42.255
        inet6 fe80::1095:a2ff:fe67:f0d9  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)
        RX packets 33987  bytes 4999738 (4.7 MiB)
        RX errors 33986  dropped 0  overruns 0  frame 33986
        TX packets 42470  bytes 40312467 (38.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

however mikrotik shows no errors. no rx tx errors or drops.. 0 drop.
https://imgur.com/a/a5DNi9m

https://imgur.com/a/a5DNi9m

it is safe to ignore ? kind of 'cosmetic bug' or really a problem?
somehow sometimes web pages loading via this connection break and bytes bigger and wasting more data plan quotas
and accounting differences.
any comments appreciated..

thank you.

mkx · Wed Sep 04, 2024 3:51 pm

Rx errors are often not detected on the other (Tx) side ... so the discrepancy in errors statistics is nothing weird. I can think of several reasons for Rx errors to happen ... ranging from "noisy" USB cable to (performance) problems in USB stack (and higher) on the android LTE device. If it was for noisy cable, then I'd expect to see some Rx errors on ROS side as well (USB cable is symmetrical) ... but who knows.

junbr0 · Wed Sep 04, 2024 6:53 pm

i think those rx errors packet fake,
because all the number of packets received are all errors,
if errors that much how it could successfully communicate ?
--------------
RX packets 33987
RX errors 33986
--------------
thats why im asking the expert here.
(ah forgive my bad english)

regards,

mkx · Wed Sep 04, 2024 11:47 pm

You're right, coukd be a bug in android's ifconfig. Another possibility is (again android's) RNDIS stack which erroneously handles ethernet frame checksum ... but doesn't discard frame due to mismatch (could be RNDIS driver on MT to blame as well).

But, as you may have guessed by now, I'm just guessing.

junbr0 · Thu Sep 05, 2024 6:56 am

thanks for your opinion mkx

TX/RX packet errors via lte rndis0 (usb)

TX/RX packet errors via lte rndis0 (usb)

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Re: TX/RX packet errors via lte rndis0 (usb)

Re: TX/RX packet errors via lte rndis0 (usb)

Re: TX/RX packet errors via lte rndis0 (usb)

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