In tests measuring TCP and UDP streaming and request-response speed, LynxOS® networking for real-time systems can even outperform Linux®—the de facto industry standard for networking excellence.

TCP request-response test results

Test results show that LynxOS usually exceeds Linux's excellent networking performance in areas such as TCP request-response. (Packet sizes and write sizes below are in bytes, and data rates are in megabits/second.)

More LynxOS networking test results are available upon request; please contact a LynuxWorks™ sales person to obtain a copy.

What is a TCP request-response test?

A TCP request-response test measures the number of request-response transactions per second. The initiating system sends a request packet of a specified size and waits for the other system to return a response packet, also of a specified size. As soon as the response is received, another request is sent.

TCP request-response performance is measured by building a single TCP connection and sending requests and responses over that connection for the lifetime of the test. The results shown here were obtained by running the netperf benchmark on the test system. LynxOS is about 60% faster for smaller sizes, with a decreasing advantage as the sizes increase.

Testing software

Netperf (http://www.netperf.org/) is a freely available benchmark that can be used to measure several types of networking performance, including TCP and UDP streaming, as well as request-response.

Testing hardware

System A Tester	System B System Under Test
933-MHz P-III Serverworks motherboard 64-bit PCI support Intel Gigabit Ethernet card Operating System: RedHat Linux 7.2 (Linux Kernel 2.4.7-10)	800 MHz P-III Intel 845 chipset Intel Gigabit Ethernet Card Operating System: RedHat Linux 7.2 (Linux kernel 2.4.7-10); LynxOS 4.0 (with Jumbo Patch 1)

These systems were connected directly via a CAT-5 crossover cable. To allow a true comparison between LynxOS and Linux networking performance, System B was first installed and tested with RedHat Linux 7.2. Once testing was complete for Linux, LynxOS was installed onto System B and the tests were repeated. System B was used to determine network performance, to reduce the risks of the results being skewed by CPU bottlenecks in the test system.