SWRU455M February 2017 – October 2020 CC3120 , CC3120MOD , CC3130 , CC3135 , CC3135MOD , CC3220MOD , CC3220MODA , CC3220R , CC3220S , CC3220SF , CC3230S , CC3230SF , CC3235MODAS , CC3235MODASF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
IP fragmentation is a method of breaking the IP packet into smaller messages compatible with the Maximum Transmission Unit (MTU) size, and reassembling them on the receive side. IPv4 routers fragment packets according to the MTU of the link. IPv6 routers do not fragment, and it is the responsibility of the device to fragment the packets. When receiving data, the SimpleLink device supports reassembling of the received IP fragmented packets for both IPv4 and IPv6. When the host application sends data which is bigger than the MTU size, the SimpleLink device splits this data into packets compliant with the MTU size without using IP fragmentation. For TCP, the size has no effect because TCP ensures byte ordering. However, for UDP the size may cause packet reordering, therefore, TI recommends that the host applications send UDP data up to the MTU size (1472 bytes for IPv4 and 1452 bytes for IPv6), or verify data integrity in higher layers.
The SimpleLink device response to a fragmented ping, the maximum ping packet payload is 19,232 bytes for Ipv4 and 27,976 bytes for IPv6.