Issue link: https://read.uberflip.com/i/1527095
LoRaWAN ® Certification Protocol Specification TS009-1.2.1 ©2024 LoRa Alliance ® Page 19 of 27 The authors reserve the right to change specifications without notice. 5.9 Echo Frame Request Commands (EchoIncPayloadReq, 417 EchoIncPayloadAns) 418 419 The EchoIncPayloadReq command payload contains the N bytes to be echoed, plus one. 420 The N value is arbitrary. In case the N value is bigger than the application payload buffer, the 421 echoed packet SHALL be clipped to the maximum payload buffer size. 422 423 Size (octets) 1 1 … 1 Fields Octet0 Octet1 … Octet N-1 Table 11: EchoIncPayloadReq 424 EchoIncPayloadReq instructs the DUT to respond with a subsequent uplink whose payload 425 content is the downlink's data incremented octet-by-octet, except the first octet, which remains 426 0x08. 427 428 Assume the received payload length is N, where N is any value between zero and the 429 maximum LoRaWAN region payload size allowed. The bytes composing the command 430 payload are: 431 432 [0x08, octet 0 , octet 1 , …, octet N-1 ] 433 434 EchoIncPayloadAns SHALL convey a payload whose content is as follows: 435 436 [0x08, mod(octet 0 + 0x01, 256), mod(octet 1 + 0x01, 256), …, mod(octet N-1 + 0x01, 437 256)] 438 439 Where mod() indicates modulo arithmetic. 440 441 For example, if the DUT receives a payload of [8 1 5 255] on FPort 224, it will respond 442 with [8 2 6 0] on FPort 224. This echo functionality is used to validate the DUT 443 cryptography implementation as well as its handling of the maximum payload for both uplinks 444 and downlinks. 445 446 The EchoIncPayloadAns SHALL be clipped to the maximum uplink frame payload size 447 allowed by the LoRaWAN Regional Specifications. 448 5.10 Applicative Rx Counter Commands (RxAppCntReq, RxAppCntAns, 449 RxAppCntRstReq) 450 451 The RxAppCntReq command requests the DUT to provide the current RxAppCnt value. This 452 command has no payload. 453 454 The DUT answers the RxAppCntReq command with an RxAppCntAns command. 455 456 Size (octets) 2 Field RxAppCnt Table 12: RxAppCntAns 457 The RxAppCntRstReq command requests the DUT to reset the RxAppCnt value to 0. This 458 command has no payload. 459 460