I am experiencing some trouble getting my OTAA’s accepted reliably.
It seems the lower datarate I go with the less likely an accept is. When tracing the UDP:1700 traffic on the network it looks like the join accept arrives too late. Even though the regular PULL_ACK’s are reported to have only about 45ms delay.
Some timing measurements done on the gateway (ethernet):
- with “
mac set dr 5” I measure 4045ms between join request and join ack
- with “
mac set dr 3” I measure 4045ms between join request and join ack
- with “
mac set dr 1” I measure 5041ms between join request and join ack
And that more than 5 seconds response time is enough to be too late for the rn2483 to catch the ack, which then of course respond “denied”
In the TTN console gateway traffic view I see the same ~4 seconds on the two first joins and the ~5 seconds on the last one.
My setup is boiled down to the simplest I could make it:
- A RN2483 module hooked to a serial terminal for me to act as the node
- A gateway consisting of an IC880A-spi wired to a RPi
- “node” and gateway are a few meters apart, I have a -20dB dampener on the gateway antenna line and -30dB on the node antenna to make sure I do not pick up other traffic.
The gateway run the regular semtech packed-forwarder, communicating on UDP:1700. I have been using the same hardware and software with loraserver without any problems, so I think the wiring is good. Only
local_conf.json are changed to match TTN.
I would appreciate suggestions on how to debug this. What else information is needed?
Also please let me know if I should have posted somewhere else instead - I couldn’t really figure out the optimal category for this mess