[aprssig] IGate Issues

Pete Loveall AE5PL Lists hamlists at ametx.com
Sat Feb 25 07:28:22 CST 2017


Hessu and I have been looking at an increase in mangled packets apparently originating out someone's IGate software (not yet identified).  These may be unrelated (out of different software) but these are the facts as we have observed via various servers:

1) Someone is processing the data portion of a packet with string functions.  This is exemplified by mangled Mic-E packets which contain non-printable and DEL characters.
2) Packets are being concatenated.  This also appears to be due to #1 but not verified. This appears to be done on non-RF packets as well indicating a potential issue within the IGate software and its server-side packet handling.
3) Concatenated packets are sometimes -minutes- old.  This could also be due to the "viscous" method of IGating described by Kenneth and Jess.  If these packets are also being delayed in a stand-alone mode, we get loops.
4) Packets gated to RF are not properly wrapped in a third-party format packet.  This also causes loops and needless overhead on RF.  Gating to RF is only to be done in the third-party format as described  in the spec and reiterated at http://www.aprs-is.net/IGateDetails.aspx

As a reminder, the data portion of the packet is to be passed -unaltered- to the upstream server, period.  Packets are -never- to be delayed to the upstream server.

IGate authors: PLEASE review your code and resolve any issues that might be applicable.  IGate authors: THANK YOU for the great work you have done.  Let's go the extra step of cleaning up our code.

73,

Pete Loveall AE5PL
pete at ae5pl dot net




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