lwIP is a small independent implementation of the TCP/IP protocol suite that has been developed by Adam Dunkels at the Computer and Networks Architectures (CNA) lab at the Swedish Institute of Computer Science (SICS).
The focus of the lwIP TCP/IP implementation is to reduce resource usage while still having a full scale TCP. This making lwIP suitable for use in embedded systems with tens of kilobytes of free RAM and room for around 40 kilobytes of code ROM.
Development of lwIP is hosted on Savannah, a central point for software development, maintenance and distribution. Everyone can help improve lwIP by use of Savannah's interface, CVS and the mailing list. A core team of developers will commit changes to the CVS source tree.
IP (Internet Protocol) including packet forwarding over multiple network interfaces
ICMP (Internet Control Message Protocol) for network maintenance and debugging
IGMP (Internet Group Management Protocol) for multicast traffic management
UDP (User Datagram Protocol) including experimental UDP-lite extensions
TCP (Transmission Control Protocol) with congestion control, RTT estimation and fast recovery/fast retransmit
raw/native API for enhanced performance
Optional Berkeley-like socket API
DNS (Domain names resolver)
SNMP (Simple Network Management Protocol)
DHCP (Dynamic Host Configuration Protocol)
AUTOIP (for IPv4, conform with RFC 3927)
PPP (Point-to-Point Protocol)
ARP (Address Resolution Protocol) for Ethernet
The original out-dated homepage of lwIP and Adam Dunkels' papers on lwIP are at the official lwIP home page:
Self documentation of the source code is regularly extracted from the current CVS sources and is available from this web page:
There is now a constantly growin wiki about lwIP at
Also, there are mailing lists you can subscribe at
plus searchable archives:
Reading Adam's papers, the files in docs/, browsing the source code documentation and browsing the mailing list archives is a good way to become familiar with the design of lwIP.
Generated on Sun Mar 23 19:22:46 2008 for lwIP 1.3.0 by