[HamGateNY] What is Old is New Again! (NetRom Parameters)

[Charles J. Hargrove]

I was looking at the old NEDA (NorthEast Digital Association)
newsletters from twenty years ago (1999) and want to show you some
pertinent NetRom parameters that might help with the bloated (some
over 100) nodes lists that we see from time to time. These started
as X1J parameters, but you might find them useful to give you an idea
how to tweak your BPQ, Xrouter, *NOS, Flex, etc systems. Each program
might use a different naming convention, but reading the details of
your documentation will align to NEDA labels. As always, adjustments
can be made for a non-standard configurations like full duplex data
repeaters, etc. Feel free to discuss the technical points here, but
gear the explanation for the newer sysops.

The parameters are broken down differently by the type of connection you
have with another station (mostly RF-based).  Adaption to an AXIP link via
wired internet should follow the Dedicated Point-to-Point Link (DPPL).

USER PORT (typical 2 meter port):
No node table is broadcast to keep channel clear. Do this by setting
Initial (Default) Obsolescence at 5 and the Minimum Obsolescence to 6.
Since the default is lower than the cutoff, it will never broadcast.

DPPL (only two backbone users on a dedicated frequency) [or AXIP]:
Your partner station should be a locked route with quality of 203.
Accept incoming nodes from your partner with minimum quality of 63.
Initial (Default) Obsolescence at 5
Minimum Obsolescence to 3
Nodes Broadcast Interval 900 seconds (15 minutes)
The obsolescence count will start at 5 and decrement by 1 every 15
minute cycle and stop when it hits 3 if there is no refresh from your
partner station. This keeps things clean and updated within 30 minutes.

Multiway Backbone with 3 Partners (typically 220 Mhz regional channel)
Your partner station should be a locked route with quality of 203.
Accept incoming nodes from your partner with minimum quality of 63.
Initial (Default) Obsolescence at 5
Minimum Obsolescence to 2
Nodes Broadcast Interval 900 seconds (15 minutes)
The obsolescence count will start at 5 and decrement by 1 every 15
minute cycle and stop when it hits 2 if there is no refresh from your
partner station. This keeps things clean and updated within 45 minutes.
This allows for occasional transmitter collisions between partners.

NOTE: current practice is to set minimum quality values at 150 or 180 is
only to mitigate the effect of mislabeled nodes qualities broadcast to
partner systems that get propagated. There are several systems that make
all of the nodes in their table higher than they should be. When the
network is cleaned out and realigned, then the minimum quality can be
adjusted downward.

How are node qualities adjusted when the nodes table is passed around
the network from partner to partner?

*** ONLY WHAT IS ON YOUR PHYSICAL BOX OR WIRED LAN SHOULD BE HIGHER THAN 
203 ***

Initial partner quality is 203 (out of 256) or 203/256
First hop between AXIP partners is   203/256 * 203/256 or 161/256
Second hop between AXIP partners is  161/256 * 203/256 or 128/256
Third hop between AXIP partners is   128/256 * 203/256 or 101/256
Fourth hop between AXIP partners is  101/256 * 203/256 or  80/256
Fifth hop between AXIP partners is    80/256 * 203/256 or  63/256


-- 
Charles J. Hargrove - N2NOV
NYC-ARECS/RACES Citywide Radio Officer/Skywarn Coord.

NYC-ARECS/RACES Nets 147.360/107.2 PL
ARnewsline Broadcast Mon. @ 8:00PM
NYC-ARECS Weekly Net Mon. @ 8:30PM
http://www.nyc-arecs.org

NY-NBEMS Net Saturdays @ 10AM & USeast-NBEMS Net Wednesdays @ 7PM
on 7.036 Mhz USB (alt 3.536)/1500 hz waterfall spot; MFSK-16 or 32

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