Kenwood TM-455E - Manual (Page 45)

7 APRS NETWORKS
TM-D710A/E CONTENTS 35
7.4.2 UIFLOOD
With UIFLOOD activated (On), when a digipeater receives a UI frame with a character string 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 only the revised character string
so as not to make the frame length too long. The UIFLOOD technique does not provide traceable
paths, so its use is not recommended except for supporting the SSn-N or SSSn-N state or regional
paths. Also the example should change to start with SS3-3 instead of WIDE3-3. UIFLOOD
should very rarely be used by mobiles.
Figure 7-6 Using UIFLOOD
The UIFLOOD method of digipeating is only a function of a full sized properly configured
permanent digipeater. If a mobile is activated with UIFLOOD, it can cause much unnecessary
interference to the network. The only time to ever activate a mobile with UIFLOOD is in very
special cases, when a mobile is being used on top of a hill to provide temporary emergency
digipeating to replace a broken or missing wide area digipeater.
7.4.3 UITRACE
UITRACE functions similar to UIFLOOD with the difference that UITRACE reports the full relay
path of digipeaters that were used to relay the message. UITRACE is the most powerful and
traceable digipeating function in APRS. It is the basis of the New-N paradigm discussed in 7.4
Digipeaters. Therefore, with UITRACE activated (On), when a digipeater receives a UI frame with
a character string 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
previous digipeaters as well as itself resulting in a frame length that becomes longer as the
message 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
very unusual circumstances.
Figure 7-7 Using UITRACE
MYCALL: W4DJY
UIFLOOD: ON
ALIAS: MD
SUBSTITUTION: ID
WB4APR-9 > APK102,
MD3-3: Test
WB4APR-9 > APK102,
W4DJY*, MD3-2: Test
MYCALL: W5DJY
UIFLOOD: ON
ALIAS: MD
SUBSTITUTION: ID
WB4APR-9 > APK102,
W5DJY*, MD3-1: Test
"MD" stands for
Maryland.
MYCALL: W4DJY
UITRACE: ON
ALIAS: WIDE
WB4APR-9 > APK102,
WIDE3-3: Test
WB4APR-9 > APK102,
W4DJY*, WIDE3-2: Test
MYCALL: W5DJY
UITRACE: ON
ALIAS: WIDE
WB4APR-9 > APK102,
W4DJY, W5DJY*,
WIDE3-1: Test