SCHC test

An test implementation of LPWAN Static Context Header Compression (SCHC).

This is developed based on the SCHC draft-09. Because the draft status is in progress. Therefore, the unclear parts are implemented by my own understanding.

To understand this implementaion detail, see IMPLEMENT.md.

Requirement

python3 is required. not tested on python2.

This software is expected to run on MicroPython. Only premitive python packageare is used so that this software can work on the device such as LoPy.

This software was written on Python2 in the early phase. There are many codes which is not likely Python3. These will be fixed in the future.

Limitations

support only 1 byte as the L2 alignment. Depends on binascii.crc32()

TODO

the compression/decompression layer are not implemented.
bitmap optimization is not implemented.

How to get

You have to download some modules with this software. Therefore, you need to clone recursively like below;

git clone --recursive git://github.com/tanupoo/schc-test.git

git clone git://github.com/tanupoo/schc-test.git
cd schc-test
git submodule update --init --recursive

Sample code

The test implementations are included. Note that they use UDP as its transport layer.

test-frag-client-udp.py is a sample code for the fragment sender. test-frag-server-udp.py is for the fragment receiver.

You can run test-frag-client-udp.py in the terminal window like below.

./test-frag-client-udp.py 127.0.0.1 9999 --context-file="example-rule/context-001.json" --rule-file="example-rule/fragment-rule-002.json" --dtag=3 -I test/message.txt --l2-size=6 -dd

And, you can run test-frag-server-udp.py in another terminal window like below.

./test-frag-server-udp.py 9999 -dd

You can refer to IMPLEMENT.md about the timer such T1.

test-frag-client

usage: test-frag-client-udp.py [-h] [-I MSG_FILE] [--read-each-line]
                          [--interval INTERVAL] [--timeout TIMEOUT]
                          [--l2-size L2_SIZE] --context-file CONTEXT_FILE
                          --rule-file RULE_FILE [--dtag _DTAG]
                          [--loss-list LOSS_LIST] [--loss-rate LOSS_RATE]
                          [--loss-random] [-d] [--debug DEBUG_LEVEL]
                          [--version]
                          SERVER PORT

a sample code for the fragment sender.

positional arguments:
  SERVER                specify the ip address of the server.
  PORT                  specify the port number in the server.

optional arguments:
  -h, --help            show this help message and exit
  -I MSG_FILE           specify the file name containing the message, default
                        is stdin.
  --read-each-line      enable to read each line, not a whole message at once.
  --interval INTERVAL   specify the interval for each sending.
  --timeout TIMEOUT     specify the number of time to wait for ACK.
  --l2-size L2_SIZE     specify the payload size of L2. default is 8.
  --context-file CONTEXT_FILE
                        specify the file name containing a context.
  --rule-file RULE_FILE
                        specify the file name containing a rule.
  --dtag _DTAG          specify the DTag. default is random.
  --loss-list LOSS_LIST
                        specify the index numbers to be lost for test. e.g.
                        --loss-list=3,8 means the 3rd and 8th packets are
                        going to be lost.
  --loss-rate LOSS_RATE
                        specify the rate of the packet loss. e.g. --loss-
                        rate=0.2 means 20% to be dropped.
  --loss-random         enable to lose a fragment randomly for test.
  -d                    increase debug mode.
  --debug DEBUG_LEVEL   specify a debug level.
  --version             show program's version number and exit

test-frag-receiver

usage: test-frag-server-udp.py [-h] [--address SERVER_ADDRESS]
                          [--context-file CONTEXT_FILE]
                          [--rule-file _RULE_FILES] [--timer TIMER_T1]
                          [--timer-t3 TIMER_T3] [--timer-t4 TIMER_T4]
                          [--timer-t5 TIMER_T5] [-d] [--debug _DEBUG_LEVEL]
                          [--version]
                          PORT

a sample code for the fragment receiver.

positional arguments:
  PORT                  specify the port number in the server.

optional arguments:
  -h, --help            show this help message and exit
  --address SERVER_ADDRESS
                        specify the ip address of the server to be bind.
                        default is any.
  --context-file CONTEXT_FILE
                        specify the file name containing a context.
  --rule-file _RULE_FILES
                        specify the file name containing a rule.
  --timer TIMER_T1      specify the number of timer T1.
  --timer-t3 TIMER_T3   specify the number of timer T3.
  --timer-t4 TIMER_T4   specify the number of timer T4.
  --timer-t5 TIMER_T5   specify the number of timer T5.
  -d                    increase debug mode.
  --debug _DEBUG_LEVEL  specify a debug level.
  --version             show program's version number and exit

tanupoo / schc-test