About the Cubesat Space Protocol

Cubesat Space Protocol (CSP) is a small network-layer delivery protocol 
designed for Cubesats. The idea was developed by a group of students from 
Aalborg University in 2008, and further developed for the AAUSAT3 Cubesat 
mission scheduled for launch in 2011. The protocol is based on a 32-bit header 
containing both transport and network-layer information. Its implementation is 
designed for, but not limited to, embedded systems such as the 8-bit AVR 
microprocessor and the 32-bit ARM and AVR from Atmel. The implementation is 
written in GNU C and is currently ported to run on FreeRTOS or POSIX operating 
systems such as Linux.

The three letter acronym CSP was originally an abbreviation for CAN Space 
Protocol because the first MAC-layer driver was written for CAN-bus. The 
physical layer has since been extended to include support for e.g. spacelink, 
I2C and RS232 interfaces and the name was thus changed to the more general 
Cubesat Space Protocol without changing the abbreviation.

The protocol and the implementation is today actively maintained by the 
students at Aalborg University and the spin-off company GomSpace.

Notable features include:

 * Simple API similar to Berkeley sockets.
 * Router core with static routes. Supports transparent forwarding of packets 
   over e.g. spacelink.
 * Support for both connectionless operation (similar to UDP), and connection 
   oriented operation (RFC 908 and 1151).
 * Service handler that implements ICMP-like requests such as ping and buffer 
   status.
 * Support for loopback traffic. This can e.g. be used for Inter-process 
   communication between subsystem tasks.
 * Optional Support for broadcast traffic if supported by the physical 
   interface.
 * Optional support for promiscuous mode if supported by the physical 
   interface.
 * Optional support for encrypted packets with XTEA in CTR mode.
 * Optional support for RFC 2104 authenticated packets with truncated 
   HMAC-SHA1. 

The source code includes a MAC layer interface for CAN bus with support for 
fragmentation. Drivers are available for the Atmel AT90CAN128, Atmel AT91SAM7A1 
and all hosts supporting the Linux SocketCAN framework, including the Analog 
Devices Blackfin DSPs. The CAN interface is easily extensible with new CPU 
architectures.

The source code is available under an LGPL 2.1 license. See COPYING for the 
license text.

You can join our Google groups list at:
http://groups.google.com/group/cubesat-space-protocol.