Issue link: https://read.uberflip.com/i/1428356
LoRaWAN Fragmented Data Block Transport v1.0.0 Specification ©2018 LoRa Alliance™ Page 7 of 30 The authors reserve the right to change specifications without notice. 3 Downlink Fragmentation Transport Message Package 145 146 The identifier of the fragmentation transport package is 3. The version of this package is 147 version 1. 148 149 This package supports all the commands necessary to transport reliably a large data block 150 from a fragmentation server to an end-device (using unicast) or a group of end-device (if 151 multicast is used over classB or classC). This package requires a dedicated port. The 152 default port value is 201. Once declared, this port cannot be used for any other purposes. 153 154 All fragmentation related messages are exchanged on this port using application payload 155 and encrypted using the end-device's AppSKey or the McAppSKey. All unicast or multicast 156 control messages use the same format: 157 Command1 Command1 Payload Command2 Command2 payload …. 158 A message MAY carry more than one command with the exception of the "Data fragment" 159 command which MUST be the only command in a message's payload. The length of each 160 command's payload is fixed and a function of the command. Commands are executed from 161 first to last. 162 163 The following table summarizes the list of fragmentation control messages 164 165 CID Command name Transmitt ed by Multicast (M) / Unicast (U) Short Description End- device server 0x00 PackageVersionReq x U Used by the AS to request the package version implemented by the end-device 0x00 PackageVersionAns x U Conveys the answer to PackageVersionReq 0x01 FragStatusReq x U/M Asks an end-device or a group of end- devices to send the status of a fragmentation session 0x01 FragStatusAns x U Conveys answer to the FragSessionStatus request 0x02 FragSessionSetupReq x U Defines a fragmentation session 0x02 FragSessionSetupAns x U 0x03 FragSessionDeleteReq x U Used to delete a fragmentation session 0x03 FragSessionDeleteAns x U 0x08 DataFragment x U/M Carries a fragment of a data block Table 1: Fragmentation Control messages summary 166 167 The message marked "U/M" can be received using a unicast or multicast address. All other 168 messages are exchanged only using the unicast end-device address. 169 170