Why is my AT&T XBee LTE-M usage so much higher than expected.

Question

I know this isn't the obvious place to ask this question, but AT&T support is not being helpfull, and other XBee users probably hang ut here.

I've got my XBee LTE-M device up and running on an AT&T IOT account (AT&T IoT Data Plan -LTE-M US).

I'm posting periodic data to website I manage. I want to minimize my data plan usage, so I assumed I should batch my uploaded data so as to not be sending lots of small packets that get padded to a minimum zize.

Currently I post data once every 30 minutes.
My entire HTTP payload is 2004 bytes long. The response I get is less than 500 bytes.
So I'd expect less than 3K data usage per post.

BUT What I'm seeing with the AT&T management/billing tool is about 8.5K of usage every post.
This takes me from the 5MB per month plan that I should be able to use, to the 25MB plan.

So what am I doing wrong?

I have disabled any automatic remote monitoring etc.
I am letting the XBee go to sleep after each post. Is this incurring wake-up transactions each time?
Do I need to hard-code my server IP to avoid DNS transactions?
What am I missing?

Phil.

So what am I doing wrong.

Answer 1

Is the Remote Manager functions turned off?

Answer 2

Yes...

As originally stated:
"I have disabled any automatic remote monitoring etc."

This was performed by setting DO (Device Options) bit 0 to 0

I assume this is all that is required to prevent any Remote Manager activity.

Comments

Yes that would disable it.   Are you accounting for the data needed to create the socket at each connect?

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No, since it's all initiated within the XBee.
How would I do that?  What does a socket connection cost?

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don't know what the cost is to create a socket but you do need to send some data to make that connection. You also have to send something to keep the connection active. But you can look at the TM and TP settings to see how often it is sent.