The 202406 release includes kernel support for Symmetric Multiprocessing (SMP) and Memory Protection Units (MPU), plus improved library IPv6 support. See the blog post.
Simplifying Authenticated Cloud Connectivity for Any Device.
How Wi-Fi and Cellular connectivity modules with ExpressLink can help create secure cloud connected devices. See the blog post.
Designing an energy efficient and cloud-connected IoT solution with CoAP.
A client/server, request/response, UDP-based protocol for efficiency and cloud compatibility. See the blog post.
Introducing FreeRTOS Kernel version 11.0.0:
A Major Release with Symmetric Multiprocessing (SMP) Support. See the blog post.
FreeRTOS Roadmap and Code Contribution process.
The FreeRTOS roadmap and code contribution process are now published here and on GitHub. See the blog post.
MSS
MSS stands for Maximum Segment Size. It
defines the maximum amount of data that can be sent or received in a
TCP or
UDP packet.
It differs from the MTU value in
that its value only applies to the data size, not the frame size, so it
excludes the Ethernet, IP, TCP or UDP protocol headers. The MSS is
dependent on the MTU and the maximum number of options bytes.
The following is an
IPv4
example MSS calculation starting from an
MTU of 1526 bytes. The number of bytes consumed by the various headers contained
within the frame are subtracted to get the MSS size:
The following is an IPv6
example MSS calculation starting from an MTU of 1526 bytes. The number of bytes consumed
by the various headers contained within the frame are subtracted to get the MSS size:
In FreeRTOS-Plus-TCP the MSS value is set by the
ipconfigTCP_MSS
setting in FreeRTOSIPConfig.h. If ipconfigTCP_MSS is not defined then it will be set to
a default value of 1460.
In the above example the calculated MSS value of 1460 bytes is suitable for a
local area network (LAN), but is probably too large for use across the Internet,
where the MSS should be restricted to 1400 bytes for maximum reliability. Therefore
if the IP address of a remote node is outside of the local network
(see netmask),
then FreeRTOS-Plus-TCP will automatically set the MSS to the smallest of either 1400 or
the configured ipconfigTCP_MSS value.
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