In an earlier test of the AIS NB-IoT Arduino shield, I touched on the fact that the AIS 923MHz NB-IoT network tested illustrated "not the best reliability" due to spotty 923MHz cell tower penetration / coverage.
However, on the ocean side of my condo, I have improved this reliability issue a few DB (my RF power meter is not very accurate, sorry) with this antenna:
More importantly than potential antenna gain, the 923MHz NB-IoT signal is considerably more reliable after placing the antenna at the window and off my desktop (which is about 3 to 4 meters away from the window).
In addition, I have the Arduino sketch sending the message to a remote Linux server via BLE and the NB-IoT network and will post the code / sketch after I add a mini-app to get some server stats like the server load averages back to the iPhone. Just need to add a few lines of code to my test Python UDP server code and change the sketch to receive the result and display it on the iPhone.
So far, it's pretty simple (after working out the conflict between serial comm pins last yesterday).
I just moved away from a T3 line back to a dial up I just wanted to know would a P200 with 64meg and a 4 gig hard drive be ok for a linux server for an additional 3 pcs all running win98. I will be dialing into an isp using a 56k v90 modem.
Any support or help will be great. (3 Replies)
Hello all
this is general question , if i have web server installed in my local pc and i have client that connecting to that web server
can i force it always to go via the internet network ?
the reason im asking is .. that im noticed when i close my internet connection i still can connect to my... (2 Replies)
hi i have linux server connected to internet through a switch/router. i have opened a port on the router and i am able to connect to the server if iptables is off. but when it is on i cant.
i want to create a rule in iptables so that it accepts packets coming from a particular datacard. it... (7 Replies)
In my further exploration of Arduino, today I decided to install the arduino-cli on my mac today.
https://github.com/arduino/arduino-cli
I followed the instructions for macOS but when I got to this part:
arduino-cli board list
I got the dreaded "Unknown" Fully Qualified Board Name... (1 Reply)
My favorite projects are always related to the "latest" tech in command and control, networking and network communications. This Elecrow GSM/GPRS/EDGE SIM5360E 3G Shield seems to be the "latest and the greatest" as far as 3G and GPS, as far as I can see so far, but I has it drawbacks for sure.... (6 Replies)
Today I received my NB-IoT Arduino Shield for AIS (Thailand). Here is a "pinout" photo of the shield.
My shield looks just like the one above, for the most part. I'll post another photo of the actual device later.
When I received the shield in the mail, I went immediately to a local... (8 Replies)
Normally I have very good experiences buying from AliExpress, but in this case with Elecrow, I'm disappointed.
After confirming with Elecrow on AliExpress that their Elecrow GSM/GPRS/EDGE SIM5360E 3G Shield for Arduino would work with 3G SIM cards in Thailand, I purchased one. My plan was to... (1 Reply)
Here is a sketch to do basic testing for the Arduino UNO and the MLT-BT04.
This BLE module works with IOS (iPhone) and I'll add some details on my IOS testing with an iPhone in a follow-up post.
For now, here is the basic BLE (HM-10) sketch for the Arduino UNO:
/*
Arduino test-code... (7 Replies)
With a little bit of work, was able to build a nice "Wuhan Coronavirus Status" app using MQTT and the IoT-OnOff app. More on this technique here:
ESP32 (ESP-WROOM-32) as an MQTT Client Subscribed to Linux Server Load Average Messages
The result turned out nice, I think. I like the look and... (10 Replies)
Normally I'm not into kits, but I thought my wife would enjoy this one since she is a big fan of robots and droids on StarWars!
We are done with the basic mechanical assembly and starting on the electronics assembly today.
The robot's "brain" consists of three levels. The Arduino board, on... (5 Replies)
Discussion started by: Neo
5 Replies
LEARN ABOUT DEBIAN
ovs-vlan-test
ovs-vlan-test(1) Open vSwitch Manual ovs-vlan-test(1)NAME
ovs-vlan-test - check Linux drivers for problems with vlan traffic
SYNOPSIS
ovs-vlan-test [-s | --server] control_ip vlan_ip
Common options:
[-h | --help] [-V | --version]
DESCRIPTION
The ovs-vlan-test utility has some limitations, for example, it does not use TCP in its tests. Also it does not take into account MTU to
detect potential edge cases. To overcome those limitations a new tool was developed - ovs-test. ovs-test is currently supported only on
Debian so, if possible try to use that on instead of ovs-vlan-test.
The ovs-vlan-test program may be used to check for problems sending 802.1Q traffic which may occur when running Open vSwitch. These prob-
lems can occur when Open vSwitch is used to send 802.1Q traffic through physical interfaces running certain drivers of certain Linux kernel
versions. To run a test, configure Open vSwitch to tag traffic originating from vlan_ip and forward it out the target interface. Then run
the ovs-vlan-test in client mode connecting to an ovs-vlan-test server. ovs-vlan-test will display "OK" if it did not detect problems.
Some examples of the types of problems that may be encountered are:
o When NICs use VLAN stripping on receive they must pass a pointer to a vlan_group when reporting the stripped tag to the networking
core. If no vlan_group is in use then some drivers just drop the extracted tag. Drivers are supposed to only enable stripping if a
vlan_group is registered but not all of them do that.
o On receive, some drivers handle priority tagged packets specially and don't pass the tag onto the network stack at all, so Open
vSwitch never has a chance to see it.
o Some drivers size their receive buffers based on whether a vlan_group is enabled, meaning that a maximum size packet with a VLAN tag
will not fit if no vlan_group is configured.
o On transmit, some drivers expect that VLAN acceleration will be used if it is available, which can only be done if a vlan_group is
configured. In these cases, the driver may fail to parse the packet and correctly setup checksum offloading or TSO.
Client Mode
An ovs-vlan-test client may be run on a host to check for VLAN connectivity problems. The client must be able to establish HTTP connec-
tions with an ovs-vlan-test server located at the specified control_ip address. UDP traffic sourced at vlan_ip should be tagged and
directed out the interface whose connectivity is being tested.
Server Mode
To conduct tests, an ovs-vlan-test server must be running on a host known not to have VLAN connectivity problems. The server must have a
control_ip on a non-VLAN network which clients can establish connectivity with. It must also have a vlan_ip address on a VLAN network
which clients will use to test their VLAN connectivity. Multiple clients may test against a single ovs-vlan-test server concurrently.
OPTIONS -s, --server
Run in server mode.
-h, --help
Prints a brief help message to the console.
-V, --version
Prints version information to the console.
EXAMPLES
Display the Linux kernel version and driver of eth1.
uname -r
ethtool -i eth1
Set up a bridge which forwards traffic originating from 1.2.3.4 out eth1 with VLAN tag 10.
ovs-vsctl -- add-br vlan-br
-- add-port vlan-br eth1
-- add-port vlan-br vlan-br-tag tag=10
-- set Interface vlan-br-tag type=internal
ifconfig vlan-br-tag up 1.2.3.4
Run an ovs-vlan-test server listening for client control traffic on 172.16.0.142 port 8080 and VLAN traffic on the default port of 1.2.3.3.
ovs-vlan-test -s 172.16.0.142:8080 1.2.3.3
Run an ovs-vlan-test client with a control server located at 172.16.0.142 port 8080 and a local VLAN ip of 1.2.3.4.
ovs-vlan-test 172.16.0.142:8080 1.2.3.4
SEE ALSO
ovs-vswitchd(8), ovs-ofctl(8), ovs-vsctl(8), ovs-test(8), ethtool(8), uname(1)Open vSwitch December 2010 ovs-vlan-test(1)