Push_ack received once

mohamed_moneib · April 4, 2020, 2:13pm

So yesterday I sent some packets and got an ack once.
I’ve kept sending since then but no ack was received, do i only receive an ack once ?

jasonreiss · April 4, 2020, 2:53pm

The network will only ACK the first packet recieved for each counter value. Others are duplicates that cannot be authenticated since any listening device could have transmitted them.

So yes, there should only be one downlink generated for a recieved confirmed uplink regardless of the number of transmissions.

mohamed_moneib · April 4, 2020, 4:44pm

Does the random value of a token count as a different message and not a duplicate though ?
And if I try to send different packets then would I get an ack ?

jasonreiss · April 4, 2020, 5:45pm

The Fcnt should be incremented for each uplink. It is a counter not a random value. The Fcnt is tracked per devaddr and must increase.

jasonreiss · April 4, 2020, 5:54pm

Are you talking about the UDP packet forwarder protocol? Then a random token is correct.

github.com

Lora-net/packet_forwarder/blob/master/PROTOCOL.TXT

	  ______                              _
	 / _____)             _              | |    
	( (____  _____ ____ _| |_ _____  ____| |__  
	 \____ \| ___ |    (_   _) ___ |/ ___)  _ \ 
	 _____) ) ____| | | || |_| ____( (___| | | |
	(______/|_____)_|_|_| \__)_____)\____)_| |_|
	  (C)2013 Semtech-Cycleo

Basic communication protocol between Lora gateway and server
=============================================================


1. Introduction
----------------

The protocol between the gateway and the server is purposefully very basic and 
for demonstration purpose only, or for use on private and reliable networks.

There is no authentication of the gateway or the server, and the acknowledges 
are only used for network quality assessment, not to correct UDP datagrams

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