PathOverkill - Revision history

KM5VY: Reverted edits by Bailey Helton (talk) to last revision by Jalles

2012-03-26T20:35:39Z

Reverted edits by Bailey Helton (talk) to last revision by Jalles

Anonymous at 08:55, 19 March 2012

2012-03-19T08:55:58Z

Jalles: /* Path Overkill */ close loopholes

2011-02-20T04:52:50Z

‎Path Overkill: close loopholes

W6DTW at 08:12, 21 August 2008

2008-08-21T08:12:51Z

W6DTW at 08:08, 21 August 2008

2008-08-21T08:08:37Z

We7u: /* Path Overkill */

2007-08-16T20:50:52Z

‎Path Overkill

KM5VY: Migrate content from old wiki

2007-08-13T23:11:28Z

Migrate content from old wiki

New page

=== Path Overkill ===

A [[Paths|path]] that specifies more hops than necessary for the area you're operating in can be considered an //abusive path//. An example of a path that's excessive or abusive almost everywhere is "WIDE1-1,WIDE3-3." This path can result in up to four "hops" - that is, it can be repeated up to four times. In virtually any area with APRS coverage, this is too much.

One of the things about the APRS Internet System ([[InternetSystem|APRS-IS]]) is that the same packet can get to the Internet by many routes, and the APRS-IS system keeps only one of them. The one it keeps is basically random - it keeps one of the many copies that arrive, and throws away the rest. While experimenting with high-hop-count paths one night, the copy that survived was one that had gone through the full four hops, and the results show exactly why this is abusive.

The route part of the packet on findu looked like this: WR6ABD,N6CP-1,WA6LDQ-3,WA6YLB-3*,WIDE3,qAo,KF6HJO

That means it had been digipeated by WR6ABD, N6CP-1, WA6LDQ-3, and WA6YLB-3 before finally being heard by the IGate KF6HJO. After looking up the locations of the digis and IGates, I created a map image of the hops it took. This one packet traveled about four hundred miles! [http://www.bestbits.org/aprs/four-hop-aprs.gif Take a look.]

This does //not// mean the four-hop route was justified. The exact same data //also// got to APRS-IS in a single hop, because there is an IGate that can hear WR6ABD, the first digipeater this packet hit. And there are certainly other routes that this same data took to get to the Internet, too; this is just the one copy that survived. The point is that a path whose hop count is too high can "light up" a wide geographic area unnecessarily, using up time on the one APRS frequency and interfering with other APRS users hundreds of miles away.

The best advice is to use a path that specifies only as many hops as you need for the way you use APRS and the area where you are using it.

← Older revision		Revision as of 20:35, 26 March 2012
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	The best advice is to specify a path that uses the minimum number of hops to accomplish your legitimate goals with the limited APRS resources in the area you are using it. Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages\|Regional Information pages]] for localized info. Above all, please be considerate of your neighbors.		The best advice is to specify a path that uses the minimum number of hops to accomplish your legitimate goals with the limited APRS resources in the area you are using it. Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages\|Regional Information pages]] for localized info. Above all, please be considerate of your neighbors.
−	~~[http://onlinehomeworkhelper.org/online-homework.php homework help online]~~

← Older revision		Revision as of 08:55, 19 March 2012
Line 10:		Line 10:

	The best advice is to specify a path that uses the minimum number of hops to accomplish your legitimate goals with the limited APRS resources in the area you are using it. Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages\|Regional Information pages]] for localized info. Above all, please be considerate of your neighbors.		The best advice is to specify a path that uses the minimum number of hops to accomplish your legitimate goals with the limited APRS resources in the area you are using it. Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages\|Regional Information pages]] for localized info. Above all, please be considerate of your neighbors.
		+	[http://onlinehomeworkhelper.org/online-homework.php homework help online]

@@ Line 1: / Line 1: @@
 === Path Overkill ===
-A [[Paths|path]] that specifies more hops than necessary for the area you're operating in can be considered an '''''abusive path'''''. An example of a path that's excessive or abusive almost everywhere is "WIDE1-1,WIDE3-3." This path can result in up to four "hops" - that is, it can be repeated up to four times. In virtually any area with APRS coverage, this is too much.
+A [[Paths|path]] that specifies more hops than necessary for the area you're operating in can be considered an '''''abusive path'''''. An example of a path that's excessive or abusive almost everywhere is "WIDE1-1,WIDE3-3." This path can result in up to four "hops" - that is, it can be repeated up to four times. In virtually any area with APRS coverage, this is too much.  In many areas, three hops is excessive.
 One of the things about the APRS Internet System ([[InternetSystem|APRS-IS]]) is that the same packet can get to the Internet by many routes, and the [[InternetSystem|APRS-IS]] system keeps only one of them. The one it keeps is basically random - it keeps one of the many copies that arrive, and throws away the rest. While experimenting with high-hop-count paths one night, the copy that survived was one that had gone through the full four hops, and the results show exactly why this is abusive.
@@ Line 7: / Line 7: @@
 Example: The route part of the packet on when viewed as "raw packets" might look like this: ''WR6ABD,N6CP-1,WA6LDQ-3,WA6YLB-3*,WIDE3,qAo,KF6HJO''
-That means it had been digipeated by WR6ABD, N6CP-1, WA6LDQ-3, and WA6YLB-3 before finally being heard by the IGate KF6HJO. This does '''''not''''' mean the four-hop route was justified. The exact same data '''''also''''' got to APRS-IS in a single hop, because there is an IGate that can hear WR6ABD, the first digipeater this packet hit. And there are certainly other routes that this same data took to get to the Internet, too; this is just the one copy that survived. The point is that a path whose hop count is too high can "light up" a wide geographic area unnecessarily, using up time on the one APRS frequency and interfering with other APRS users hundreds of miles away.
+That means it had been digipeated by WR6ABD, N6CP-1, WA6LDQ-3, and WA6YLB-3 before finally being heard by the IGate KF6HJO. This does '''''not''''' mean the four-hop route was justified. The exact same data '''''also''''' got to APRS-IS in a single hop, because there is an IGate that can hear WR6ABD, the first digipeater this packet hit. And there are certainly many more digipeaters involved and other routes that this same data took to get to the Internet, too; this is just the one copy that survived. The point is that a path whose hop count is too high can "light up" a wide geographic area unnecessarily, using up time on the one APRS frequency and interfering with other APRS users hundreds of miles away.
-The best advice is to use a path that specifies only as many hops as you need for the way you use APRS and the area where you are using it.  Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages|Regional Information pages]] for localized info.
+The best advice is to specify a path that uses the minimum number of hops to accomplish your legitimate goals with the limited APRS resources in the area you are using it.  Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages|Regional Information pages]] for localized info.  Above all, please be considerate of your neighbors.

@@ Line 3: / Line 3: @@
 A [[Paths|path]] that specifies more hops than necessary for the area you're operating in can be considered an '''''abusive path'''''. An example of a path that's excessive or abusive almost everywhere is "WIDE1-1,WIDE3-3." This path can result in up to four "hops" - that is, it can be repeated up to four times. In virtually any area with APRS coverage, this is too much.
-One of the things about the APRS Internet System ([[InternetSystem|APRS-IS]]) is that the same packet can get to the Internet by many routes, and the APRS-IS system keeps only one of them. The one it keeps is basically random - it keeps one of the many copies that arrive, and throws away the rest. While experimenting with high-hop-count paths one night, the copy that survived was one that had gone through the full four hops, and the results show exactly why this is abusive.
+One of the things about the APRS Internet System ([[InternetSystem|APRS-IS]]) is that the same packet can get to the Internet by many routes, and the [[InternetSystem|APRS-IS]] system keeps only one of them. The one it keeps is basically random - it keeps one of the many copies that arrive, and throws away the rest. While experimenting with high-hop-count paths one night, the copy that survived was one that had gone through the full four hops, and the results show exactly why this is abusive.
 Example: The route part of the packet on when viewed as "raw packets" might look like this: ''WR6ABD,N6CP-1,WA6LDQ-3,WA6YLB-3*,WIDE3,qAo,KF6HJO''
-That means it had been digipeated by WR6ABD, N6CP-1, WA6LDQ-3, and WA6YLB-3 before finally being heard by the IGate KF6HJO. After looking up the locations of the digis and IGates, I created a [http://www.bestbits.org/aprs/four-hop-aprs.gif map image of the hops it took]. This one packet traveled about four hundred miles!
+That means it had been digipeated by WR6ABD, N6CP-1, WA6LDQ-3, and WA6YLB-3 before finally being heard by the IGate KF6HJO. This does '''''not''''' mean the four-hop route was justified. The exact same data '''''also''''' got to APRS-IS in a single hop, because there is an IGate that can hear WR6ABD, the first digipeater this packet hit. And there are certainly other routes that this same data took to get to the Internet, too; this is just the one copy that survived. The point is that a path whose hop count is too high can "light up" a wide geographic area unnecessarily, using up time on the one APRS frequency and interfering with other APRS users hundreds of miles away.
-This does '''''not''''' mean the four-hop route was justified. The exact same data '''''also''''' got to APRS-IS in a single hop, because there is an IGate that can hear WR6ABD, the first digipeater this packet hit. And there are certainly other routes that this same data took to get to the Internet, too; this is just the one copy that survived. The point is that a path whose hop count is too high can "light up" a wide geographic area unnecessarily, using up time on the one APRS frequency and interfering with other APRS users hundreds of miles away.
+The best advice is to use a path that specifies only as many hops as you need for the way you use APRS and the area where you are using it.  Because each region's geographical and RF propagation characteristic is unique, it's best to check the [[RegionalPages|Regional Information pages]] for localized info.
-−
 The best advice is to use a path that specifies only as many hops as you need for the way you use APRS and the area where you are using it.