SV: [Xastir] Annoucement: Serverbased user changeable filters (fwd)
Roger Bille
roger.bille at telia.com
Thu Jan 30 17:19:58 EST 2003
All,
This is the original message however it has been updated since. I have
added 4 more filters by users requests. The full destription is located
here:
http://www.aprs-is.net/javAPRSSrvr/javaprsfilter.htm
Don't hestitate to contact me if you run into any problem or questions
about the filter.
Have fun
73 de sm5nrk/Roger
> -----Ursprungligt meddelande-----
> Från: xastir-bounces at xastir.org [mailto:xastir-bounces at xastir.org]För
> Curt Mills, WE7U
> Skickat: den 30 januari 2003 22:52
> Till: xastir at krypton.hscs.virginia.edu
> Ämne: [Xastir] Annoucement: Serverbased user changeable filters (fwd)
>
>
>
> Here's the original message. Now you know how to play with it.
>
> --
> Curt Mills, WE7U hacker_NO_SPAM_ at tc.fluke.com
> Senior Methods Engineer/SysAdmin
> "Lotto: A tax on people who are bad at math!"
> "Windows: Microsoft's tax on computer illiterates!" -- WE7U
> "The world DOES revolve around me: I picked the coordinate system!"
>
> ---------- Forwarded message ----------
> Date: Sat, 11 Jan 2003 10:32:23 +0100
> From: Roger Bille <roger.bille at telia.com>
> To: TAPR APRS Special Interest Group <aprssig at lists.tapr.org>
> Subject: [aprssig] Annoucement: Serverbased user changeable filters
>
>
> Dear all,
>
> Introduction:
> The APRS-IS full feed today have a lot of traffic and require a high
> bandwidth, in particular for the APRS-IS server sites, but also
> for some of
> you that connect that are only interested in the particular traffic. To
> accommodate this a number of servers have special regional feeds which
> filter the traffic. There are also some weather specific feeds available.
> But all these are setup according to what the server operator
> "thinks" will
> be good for the users. Now we can take this one step further.
>
> Now will each of you be able to select what traffic you are interested in
> and the server will create a unique feed for you. There is great
> flexibility
> to construct your personal feed.
>
>
> How does it work?
> Pete Loveall AE5PL have written the APRS-IS server software
> javAPRSSrvr in
> java which is used by a number of servers. Pete has been kind to
> create some
> hooks into his server software so I have been able to write a
> filter add-on,
> javAPRSFilter (also in java). These 2 applications work together
> to provide
> this filtering. Status on the APRS-IS servers can be found here:
> http://ahubswe.net/aprs_stat.asp
>
> You define the filter by doing the following:
>
> 1. Connect and logon to a filter enabled port on a server
> 2. Send an APRS message to the server requesting the filter you want
>
>
> Filter commands
> There are 4 different kinds of filters that can be used in any
> combination.
> Each filter is working independent and is additive to the feed.
> This mean if
> the filter finds a match it will be passed to you. The filter commands in
> the APRS message to the servers call is starting with the word 'filter'
> (without quotes) and each filter command is delimited by a single space. A
> message with just 'filter?' (without quotes) will return the
> current filter
> definition.
>
>
> #1 Range filter
> The range filter will pass all stations and their beacons,
> status, messages
> etc within a distance from a set location. It will also pass messages to
> stations within the filter and positions of the message sender
> even if they
> are outside the range. Up to 3 range filters can be used at the
> same time to
> extend the areas when you have problem to find a good circle match.
>
> Syntax: r/lat/lon/dist [r/lat1/lon2/dist2 [[r/lat2/lon2/dist2]]
>
> Where: r = range command
> lat = latitude in degrees (no decimals). Negative for south
> lon = longitude in degrees (no decimals). Negative for west
> dist = distance in kilometers from lat/lon.
> I'm sorry we don't use miles here in Sweden ;-)
>
> Samples: r/55/-4/600 This will pass all traffic for UK
> r/37/-81/1500 This will pass all east cost US traffic
>
>
> #2 Prefix filter
> The prefix filter will pass traffic based on if the sender’s call starts
> with a specific pattern. Up to 10 patterns can be defined at the
> same time.
>
> Syntax: p/p1/p2/p3... (up to 10)
>
> Where: p = prefix command
> p# = The prefix (starting) pattern
>
> Samples: p/K This will pass all traffic from
> stations starting with K
> p/SK/F This will pass stations starting with either SK or F
> p/SM5NRK This will pass all traffic from
> SM5NRK and any SSID at the end
>
>
> #3 Budlist filter
> The budlist filter will pass traffic based on exact match of the sender’s
> call. Also the SSID is part of the exact match. If you want all SSID use
> prefix filter above. Up to 10 calls can be defined at the same
> time (if they
> can fit in a single APRS message).
>
> Syntax: b/call1/call2/call3... (up to 10)
>
> Where: b = budlist command
> call# = The prefix (starting) pattern
>
> Samples: b/SM5NRK This will pass all traffic
> from SM5NRK without any SSID
> b/SM5NRK-5/SK5UM This will pass all traffic
> from SM5NRK-5 and SK5UM
>
>
> #4 Type filter
> The type filter will pass traffic depending on the packet type. More than
> one type can be defined in one single command.
>
> Syntax: t/type
>
> Where: t = type command
> type = is one or more of the following letters
> p = Position packets
> o = Objects
> i = Items
> m = Message
> n = NWS Weather
> w = Weather
> t = Telemetry
> q = Query
> s = Status
> u = User-defined
>
> Samples: t/p This will pass all traffic with a position
> t/w This will pass all weather traffic.
> For positionless
> weather objects the corresponding
> position packet
> will also be sent when it is next heard
> t/mos This will pass all messages,
> objects and status traffic
>
>
> Remeber that the APRS message must start with the word filter and the the
> commands.
>
> The above filters can be combined as explain above. Each filter will
> however working independent of the others, for example:
>
> filter r/63/16/1000 r/55/-4/600 p/F b/AE5PL t/s
>
> The above filter will pass all traffic within Nordic (range#1) AND UK
> (range#2) AND stations starting with F (prefix) AND from AE5PL
> (budlist) AND
> all status traffic (type).
>
>
> Where to connect?
> This is up to each server operator if/when they will provide this type of
> service. The following servers and ports have this enabled as far
> as I know.
>
> ahubswe.net:14580
> aprsca.net:14580
> aprseast.net:14580
> aprswest.net:14580
>
>
> I welcome any comments, suggestions and complains. I monitor the UI-View
> and APRSSIG lists.
>
> 73 and have fun
> Roger Bille/SM5NRK
>
>
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