Issue link: https://read.uberflip.com/i/1494345
LoRaWAN ® Certification Protocol Specification TS009-1.1.0 ©2023 LoRa Alliance ® Page 19 of 26 The authors reserve the right to change specifications without notice. 5.9 Echo Frame Request Commands (EchoIncPayloadReq, 413 EchoIncPayloadAns) 414 415 The EchoIncPayloadReq command payload contains the N bytes to be echoed, plus one. 416 The N value is arbitrary. In case the N value is bigger than the application payload buffer, the 417 echoed packet SHALL be clipped to the maximum payload buffer size. 418 419 Size (octets) 1 1 … 1 Fields Octet0 Octet1 … Octet N-1 Table 11: EchoIncPayloadReq 420 EchoIncPayloadReq instructs the DUT to respond with a subsequent uplink whose payload 421 content is the downlink's data incremented octet-by-octet, except the first octet, which remains 422 0x08. 423 424 Assume the received payload length is N, where N is any value between zero and the 425 maximum LoRaWAN region payload size allowed. The bytes composing the command 426 payload are: 427 428 [0x08, octet 0 , octet 1 , …, octet N-1 ] 429 430 EchoIncPayloadAns SHALL convey a payload whose content is as follows: 431 432 [0x08, mod(octet 0 + 0x01, 256), mod(octet 1 + 0x01, 256), …, mod(octet N-1 + 0x01, 433 256)] 434 435 Where mod() indicates modulo arithmetic. 436 437 For example, if the DUT receives a payload of [8 1 5 255] on FPort 224, it will respond 438 with [8 2 6 0] on FPort 224. This echo functionality is used to validate the DUT 439 cryptography implementation as well as its handling of the maximum payload for both uplinks 440 and downlinks. 441 442 The EchoIncPayloadAns SHALL be clipped to the maximum uplink frame payload size 443 allowed by the LoRaWAN Regional Specifications. 444 5.10 Applicative Rx Counter Commands (RxAppCntReq, RxAppCntAns, 445 RxAppCntRstReq) 446 447 The RxAppCntReq command requests the DUT to provide the current RxAppCnt value. This 448 command has no payload. 449 450 The DUT answers the RxAppCntReq command with an RxAppCntAns command. 451 452 Size (octets) 2 Field RxAppCnt Table 12: RxAppCntAns 453 The RxAppCntRstReq command requests the DUT to reset the RxAppCnt value to 0. This 454 command has no payload. 455 456