[Xastir] UDP frames

[jeff at aerodata.net]

Don't forget, frames sent via 802.11b, ride atop its own mac layer. Your
assured of your UDP frame making it to the wired access point, as it is
encapsulated inside the 802.11x frame. Once it gets on the internet, that
is stripped off, but one could make a fair assumption that a wired network
is less lossy then a rf one.

APRS "breaks" the MAC layer (ax.25), and that is why it is so unreliable
on RF and one has to flood networks to get any measure of reliablity.



> In as far as I know, bob doesn't want an ack from everyone.... only
> messages(nothing do to with the transport layer), and if they are not
> ack'ed,
> then the APRS client would initiate another packet.  Broadcast with TCP
> would
> be a nightmare with potentially 254 ack's and 254packets / aprs packet on
> the
> subnet.
>
> UDP has the same function as UI frames, and bob b lives with collisions on
> UI
> frames all the time.
>
> wes
> --
>
>
>
> Quoting Gerry Creager n5jxs <gerry.creager at tamu.edu>:
>
>> The conventional wisdom on the APRS list is that UDP is evil, because
>> Bob wants an ack from everyone.  Every time.  Never mind that APRS uses
>> UI data to work.
>>
>> Steve D. has supported him in the past.  I'm still working on him, but
>> not real actively.
>>
>> I expect the next generation of the IS will look more like multicast
>> than connected unicast, but that's my opinion.
>>
>> Would it work?  Sure.  Would it be as "reliable" as the connected
>> version?  I suspect that statistically, it would be, but the occasional
>> lost packet would be seized on a failure.
>>
>> gerry
>>
>> Wes Johnston wrote:
>> > This is probably a silly question... but some of my best ideas start
>> out
>> > silly....
>> >
>> > There was talk on the APRS sig last week about hooking up an 802.11b
>> card
>> to an
>> > amp, and transmitting UDP frames to the local subnet broadcast
>> address.
>> Can we
>> > do that with xastir?  Can we rx UDP frames with xastir? I know scott
>> miller
>> was
>> > talking about using network broadcast of UDP for open trac.... so
>> could it
>> be
>> > implemented now?
>> >
>> > wes
>> > _______________________________________________
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>> > Xastir at xastir.org
>> > https://lists.xastir.org/mailman/listinfo/xastir
>> >
>>
>> --
>> Gerry Creager -- gerry.creager at tamu.edu
>> Texas Mesonet -- AATLT, Texas A&M University
>> Cell: 979.229.5301 Office: 979.458.4020
>> FAX:  979.847.8578 Pager:  979.228.0173
>> Office: 903A Eller Bldg, TAMU, College Station, TX 77843
>>
>
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