[aprssig] packet delays through internet

Russ Chadwick russ at wxqa.com
Sun Mar 20 16:07:05 EDT 2011

Regarding the EOSS balloon packet delays through the internet that were 
reported last weekend:

Significant packet delays were noted through an I-gate that consisted of 
a D710, UI-View and Comcast ISP.  We (Mark, KC0D; Nick, N0LP; and I) did 
tests yesterday and found the problem to be that UI-View was using 
Xon/Xoff flow control while the D710 was not using flow control.  Delays 
of a few minutes to 90 minutes were noted with this set-up.

After we changed UI-View to having no flow control, expected delays of 
just a few seconds were noted almost all of the time.  In addition to 
the delays becoming normal, the problem with bad characters in the 
I-gated packets also went away.

At 2000 on March 19 we started a test where a timestamped packet on 
144.340 MHz was sent to the I-gate every minute.  This test continued 
overnight to 1800 on March 20.  The results for each packet can be 
viewed here,


Russ  KB0TVJ

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