This was developed for a very specific testing purpose, but is a simple python routine that listens for a connection and then begins sending packets to a connected client at a given rate.
Execute with 1000ms frequency, listening on port 8888, verbose output:
./PacketSpitter.py -r 1000 -p 8888 -v
The payload of the packet is a ASCII 19-digit zero-padded timestamp of UTC milliseconds since Unix Epoch followed by a CR (0x0D), for example:
0000001490303038014\r