TH-D72A/E - N3UJJ

7 APRS NETWORKS7.4.2 UIFLOODWith UIFLOOD activated (On), when a digipeater receives a UI frame with a character string for aliasin the form XXXXn-N where XXXX matches the alias character string in the digipeater, the digipeatersubtracts 1 from N and processes the packet reporting only the revised character string so as not tomake the frame length too long. The UIFLOOD technique does not provide traceable paths, so itsuse is not recommended generally. UIFLOOD is used for supporting the SSn-N or SSSn-N state orregional paths. Also the example should be changed to start with SS3-3 instead of WIDE3-3.UIFLOOD should very rarely be used by mobiles.WB4APR-7 > APK103,MD3-3: TestWB4APR-7 > APK103,W4DJY-1*, MD3-2: TestWB4APR-7 > APK103,W5DJY-1*, MD3-1: TestMy Callsign: W4DJY-1UIflood: OnAlias: MDSubstitution: IDMy Callsign: W5DJY-1UIflood: OnAlias: MDSubstitution: IDFigure 7-6 Using UIFLOODThe UIFLOOD method of digipeating is only a function of a full sized properly configured permanentdigipeater. If a normal mobile station is activated with UIFLOOD, it can cause much unnecessaryinterference to the network. The only time to ever activate a mobile station with UIFLOOD is in veryspecial cases, when a mobile station is being used on top of a hill to provide temporary emergencydigipeating to replace a broken or missing wide area digipeater.7.4.3 UITRACEUITRACE functions similar to UIFLOOD with the difference that UITRACE reports the full relay pathof digipeaters that were used to relay the message. UITRACE is the most powerful and traceabledigipeating function in APRS. It is the basis of the New-N paradigm discussed in 7.4 Digipeaters.Therefore, with UITRACE activated (On), upon receipt of a UI frame by a digipeater with a characterstring for alias in the form XXXXn-N where XXXX matches the alias character string in the digipeater,the digipeater subtracts 1 from N and processes the packet reporting each of the previousdigipeaters. This causes the digipeater itself to produce a frame length that becomes longer as themessage is relayed. Using UITRACE allows you to confirm the exact routing of any message.Like UIDIGI and UIFLOOD, UITRACE should normally never be enabled by a mobile except in veryunusual circumstances.WB4APR-7 > APK103,WIDE2-2: TestWB4APR-7 > APK103,W4DJY-1*, WIDE2-1: TestWB4APR-7 > APK103,W4DJY-1, W5DJY-1,WIDE2*: TestMy Callsign: W4DJY-1UItrace: OnAlias: WIDEFigure 7-7 Using UITRACEMy Callsign: W5DJY-1UItrace: OnAlias: WIDE58 CONTENTS TH-D72A/EFrom The N3UJJ.COM Document Library