Update README and add Python examples.

# Predictably Reliable Real-Time (PRRT)

## Hardware Timestamping

**PRRT** is a transport protocol that aims to provide predictable reliability and latency. [http://larn.systems]()

* Hardware timestamping can be enabled per socket by calling `PrrtSocket_enable_hardware_timestamping()` and specifying the interface.

* Requirements are a kernel that supports physical timestamping. Instructions can be found

## Features

### Compiling a hardware tmestamping enabled kernel on Ubuntu

* Forward Error Correction (FEC) using systematic Vandermonde codes

* Clock synchronization between sending stack and receiving stack

* Applications can specify packet-level expiration times

* Different receive modes for ASAP and time-synchronized operation

* Packet-level timing analysis using [X-Lap](http://xlap.larn.systems)

* [Hardware timestamping support](https://git.nt.uni-saarland.de/LARN/PRRT/wikis/hardware-timestamping)

* A detailed tutorial on kernel compilation can be found [here](https://help.ubuntu.com/community/Kernel/Compile).

* Create and enter a new folder, e.g. in your home directory that will store the newly compiled kernel.

* Run the following commands to download all resources required:

## Installation

```bash

sudo apt install libncurses5 libncurses5-dev

*See [Installing PRRT](https://git.nt.uni-saarland.de/LARN/PRRT/wikis/installation#python) for instructions on how to install it on your system for using it with C/C++ or Python.*

#### *Try PRRT on your system*

A [minimal receiver](examples/receiver.py), which takes the bind port as an argument, is created as follows:

```python

import sys

import prrt

port = int(sys.argv[1])

sudo apt build-dep linux-image-`uname -r`

apt source linux-image-`uname -r`

s = prrt.PrrtSocket(port=port, isSender=False)

cd linux-$(uname -r | awk '{split($1,a, "-"); print a[1]}')

while True:

    d = s.recv()

    if d != "Close":

        print d

    else:

        break

```

* Copy the current kernel configuration to the current folder:

A [minimal sender](sender.py) is created as follows:

```python

import sys

import prrt

host = sys.argv[1]

port = int(sys.argv[2])

s = prrt.PrrtSocket(port=port, isSender=True)

s.connect(host, port)

for i in range(10):

    s.send("Packet {}".format(i))

s.send("Close")

```

Start the receiver by:

```bash

cp -vi /boot/config-`uname -r` .config

python receiver.py 5000

```

* Edit the `.config` file and ensure the following line is present (and the option is set to `y`):

In a separate terminal, run:

```bash

...

CONFIG_NETWORK_PHY_TIMESTAMPING=y

...

python sender.py 127.0.0.1 5000

```

* Call `make deb-pkg` (ideally with `-j5` or some other number to speed up the compilation by using multiple cores).

* Install the `linux-headers-*.deb` and `linux-image-*.deb` package via `dpkg -i` (where * stands for the respective kernel version).

* Reboot the system.

This should generate the following output in the receiver console:

```terminal

Packet 0

Packet 1

...

Packet 9

```

## Docker

## For more information

The following shows how to run the PRRT sender and receiver on a host with OpenvSwitch.

* [PRRT Wiki](https://git.nt.uni-saarland.de/LARN/PRRT/wikis)

* [LARN Project Website](http://larn.systems)

```bash

bridge=$(docker network create --subnet="10.5.1.0/24" prrt | cut -c1-12) 

ovs-vsctl add-port of-switch br-$bridge 

## License

docker run --rm --name=prrt_recv --network="prrt" -v=/opt/prrt:/output --ip=10.5.1.52 --cap-add NET_ADMIN docker.nt.uni-saarland.de/larn/prrt:develop receiver -p 5000 -r 127 

docker run --rm --name=prrt_send --network="prrt" -v=/opt/prrt:/output --ip=10.5.1.51 --cap-add NET_ADMIN docker.nt.uni-saarland.de/larn/prrt:develop sender -t 10.50.1.52 -p 5000 -r 127 rate 1mbit

```

 No newline at end of file

[MIT Licence](LICENSE)

import sys

import prrt

port = int(sys.argv[1])

s = prrt.PrrtSocket(port=port, isSender=False)

while True:

    d = s.recv()

    if d != "Close":

        print d

    else:

        break

import sys

import prrt

host = sys.argv[1]

port = int(sys.argv[2])

s = prrt.PrrtSocket(port=port, isSender=True)

s.connect(host, port)

for i in range(10):

    s.send("Packet {}".format(i))

s.send("Close")

        'Intended Audience :: Developers',

        'Topic :: Communications'

        # Supported Python Versions

        'Programming Language :: Python :: 2',

        'Programming Language :: Python :: 2.7',

        'Programming Language :: Python :: 3',

        'Programming Language :: Python :: 3.2',

        'Programming Language :: Python :: 3.3',

        'Programming Language :: Python :: 3.4'

        'Programming Language :: Python :: 3.5'

    ],

    install_requires=["cython"],

    keywords='prrt protocol',