[aprssig] APRS Email from Space! (ET Phone Home)

Pete Loveall AE5PL Lists hamlists at ametx.com
Sun Jun 30 07:41:30 EDT 2019


And this is why I am sad to see you went ahead with this against my talks with you (initiated by you, BTW) before the launch.

It is SPAM when you are trying to do something with an email server that it was specifically designed not to do.  As stated before to you, APRS/email servers rely on numbered messages to differentiate between messages, acknowledge those messages, and to report to the sender the status of the emails being sent.  None of those 3 premises are supported by your satellite.

Your statement about the APRS protocol or FCC rules not prohibiting inanimate satellites from transmitting packets is nonsensical.  I never said it was prohibited.  I said your use of the numbered messaging protocol by using static numbered messages to try to broadcast a message to a station (the email server) without supporting acks and without supporting received numbered messages is breaking the APRS protocol.

Yes, the numbered message definition in the APRS spec relies on bidirectional communications.  If you were to use unnumbered messages that do not require bidirectional communications, the email servers would not respond to unnumbered messages.  Contrary to your claim that the code could not be changed from over a year ago, you first approached me with this concept earlier this year using unnumbered messages.  I told you at that time that email servers depend on the bidirectional nature of numbered messages to differentiate between messages, to acknowledge receipt of the messages, and to provide information to the sender on the status of the email generation/delivery.  Since you are using numbered messages, I assume you made the change in the code and ignored my admonishment that using numbered messages from a device that is not able to receive or properly ack responses was, in essence, an abuse of the protocol and the email servers.  Or maybe you just made the satellite capable of sending any message you define on the fly and so you are just broadcasting a predefined numbered message which is even worse.

If you didn't want this discussion, maybe you should have thought about what I explained to you in the first place before the launch.

73,

Pete Loveall AE5PL
pete at ae5pl dot net



-----Original Message-----
From: Robert Bruninga <bruninga at usna.edu> 
Sent: Saturday, June 29, 2019 11:15 PM
To: TAPR APRS Mailing List <aprssig at lists.tapr.org>
Subject: RE: [aprssig] APRS Email from Space! (ET Phone Home)

Pete,

An APRS Email is not spam when it is a point-to-point email from our
satellite to me reporting its status.  A vital function.

There is nothing in the APRS protocol or FCC rules that prohibits inanimate
amateur satellites from transmitting packets.

Further, there is nothing that requires bi-directional APRS Message packets.
The protocol was designed to allow APRS messages *without* line numbers so
that bi-directional acks were not required.  This was to declutter the
channel when the path was unreliable.

And the satellite code was finished more than a year ago when the satellite
was finished, and began space qualification testing.  Once it passed all
vibration and other space quals and final performance checks,  one *cannot*
change the code or it invalidates all the space qualification testing.

Bob Bruninga, WB4APR


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