The purpose of this tool is to validate a network's capability for multicast communication, so that one can confirm that the network communication requirements of DDS are fulfilled. It is intended to be simple to use, readable, and "just work" out of the box with no complicated dependencies.
The application can perform one of two roles, the transmitter or the receiver, which can be chosen by starting the tool
with the keyword argument transmitter or receiver, respectively. To validate the multicast communication,
the transmitter sends a defined set of data, and the receiver receives and checks if that defined set of data
is received properly, or possibly there were losses or duplicates.
The transmitter and receiver processes may be on different virtual or physical machines on the same network, and more than one receiver can be used at the same time to receive data from one transmitter. The user is expected to know what network they want to test, so the arguments for the multicast address and the network interface are mandatory. The optional arguments are mostly for playing with parameters such as message count, size, frequency.
transmitter:
usage: udpTester.py transmitter [-h] [-a ADDRESS] [-i INTERFACE] [-p PORT] [-t TOTALCOUNT] [-m MESSAGESIZE] [-s PACKETSIZE]
[-f FREQUENCY] [-l LOSSINESS]
Send messages via multicast. If the receiver receives all of them, the network has passed the test.
optional arguments:
-h, --help show this help message and exit
-a ADDRESS, --address ADDRESS
Mandatory argument: The ip address to use. Multicast addresses range from 224.0.0.0 to 239.255.255.255
-i INTERFACE, --interface INTERFACE
Mandatory argument: This is the network interface address to use
-p PORT, --port PORT The port number to use.
-t TOTALCOUNT, --totalcount TOTALCOUNT
Number of messages
-m MESSAGESIZE, --messagesize MESSAGESIZE
Bytes per message. A message may consist of multiple packets.
-s PACKETSIZE, --packetsize PACKETSIZE
Bytes per packet sent
-f FREQUENCY, --frequency FREQUENCY
transmitter option: Frequency of sending messages in unit Hz.
-l LOSSINESS, --lossiness LOSSINESS
transmitter option: Randomly skip sending a packet, chance in unit %.
Example:
python3 udpTester.py transmitter -a 239.0.0.1 -i 192.168.2.33 -t 200 -m 450 -s 150 -f 60
receiver:
usage: udpTester.py receiver [-h] [-a ADDRESS] [-i INTERFACE] [-p PORT] [-t TOTALCOUNT] [-m MESSAGESIZE] [-s PACKETSIZE]
[-b RECEIVEBUFFER] [-r REPORTINTERVAL]
Receive multicast messages. If I receive all messages from the transmitter, the network has passed the test.
The results will also show latency values in microseconds, calculated as current_time - source_timestamp. These values
are not reliable when transmitter's and receiver's clocks are not precisely synchronized, and may be negative when the
receiver's clock is trailing the transmitter's clock.
optional arguments:
-h, --help show this help message and exit
-a ADDRESS, --address ADDRESS
Mandatory argument: The ip address to use. Multicast addresses range from 224.0.0.0 to 239.255.255.255
-i INTERFACE, --interface INTERFACE
Mandatory argument: This is the network interface address to use
-p PORT, --port PORT The port number to use.
-t TOTALCOUNT, --totalcount TOTALCOUNT
Number of messages
-m MESSAGESIZE, --messagesize MESSAGESIZE
Bytes per message. A message may consist of multiple packets.
-s PACKETSIZE, --packetsize PACKETSIZE
Bytes per packet sent
-b RECEIVEBUFFER, --receivebuffer RECEIVEBUFFER
receiver option: receivebuffer size in bytes.
-r REPORTINTERVAL, --reportinterval REPORTINTERVAL
receiver option: Number of messages per report.
Example:
python3 udpTester.py receiver -a 239.0.0.1 -i 192.168.2.33 -t 200 -m 450 -s 150 -b 200000