[Xastir] Help with Acks

[Lynn W. Deffenbaugh (Mr)]

APRSISCE/32's acks are also callsign-specific.  The ack has to come back 
from the same station to which the sequenced message was sent to be 
considered an ack of that message.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 9/27/2012 12:00 PM, Tom Russo wrote:
> On Thu, Sep 27, 2012 at 10:06:04AM -0400, we recorded a bogon-computron collision of the <jgorkos at gmail.com> flavor, containing:
>> I'm using Xastir to test the AVRS/Locate server, and I'm having a hard time
>> grasping the reply-acks concept.
>> Here's a sample of the conversation:
>> AB0OO>APX201,TCPIP*,qAC,T1FIFTH::LOCATE   :N5TEX-9{0a}7
>> Sending ACK to AB0OO for MSG NUM 0a}7
>> Thu Sep 27 06:58:25 PDT 2012:  AB0OO wants to know the location of 'N5TEX-9'
>> Sending AVRS>APZ013,TCPIP*::AB0OO    :ack0a}7
>> Thu Sep 27 06:58:25 PDT 2012:  Last position of N5TEX-9 at Tue Sep 25
>> 16:41:44 PDT 2012 at 3609.17N/09555.35Wj
>> lastHeard is Tue Sep 25 16:41:44 PDT 2012
>> LOCATE>APZ013,TCPIP*::AB0OO    :N5TEX-9 heard 1d14h16m41s ago 3.91mi E of
>> Tulsa, OK{8
>> AB0OO>APX201,TCPIP*,qAC,T1FIFTH::LOCATE   :ack8{8
>>
>> Briefly:  AB0OO using Xastir sends a message to "LOCATE" with the callsign
>> of N5TEX-9.  The LOCATE server sees that, and acks immediately, so Xastir
>> stops sending the request. Then the LOCATE server looks up the last known
>> position for N5TEX-9, and sends a new message (with a new message number) to
>> AB0OO.
>>
>> So, Xastir is using the reply-acks format, as described here:
>> www.aprs.org/aprs11/replyacks.txt
>> The "message number" is "0a}7" when viewed from the original paradigm.   I
>> attempt to send that ack to the Xastir client in the line that starts with
>> "Sending ACK", but for some reason , Xastir ignores it.  Am I using the
>> incorrect format for my ack?  Eventually (tomorrow, I hope), I'll implement
>> the reply-acks algo, but I need this to work for ALL clients, regardless of
>> whether they use the new paradigm or the old paradigm, so this testing is
>> important.
>>
>> Any thoughts?
> I just spent some time looking at this (messaged you a few times).
>
> When your LOCATE server sends an ack, it's sending it from the AVRS call-sign.
>
> Looking through Xastir source, when Xastir receives an ack, it looks through
> its message queue for a message to that callsign with that sequence number,
> so I believe what is happening is that it has no messages in its outgoing
> queue for AVRS, and doesn't do anything with it.
>
> If your server replied with its callsign being the same as the one to which
> xastir had directed a message (i.e., LOCATE instead of AVRS), then it would
> probably recognize the ACK.
>
> Xastir's sequence numbers are not globally unique, but unique per conversation.
>
> I see you just replied to my message about that, so I'll end it here.
>