dwight@timeinc.UUCP (Dwight Ernest) (08/01/85)
[ This file relating to the Mid Atlantic Packet Radio Council was downloaded on packet radio from WB2MNF digipeater in Medford, NJ by Dwight Ernest, KA2CNN, on 30 July 1985, and is presented here for consideration. There are two portions--an originating proposal for the MAPRC, and an expression of its future plans. I found it interesting. I hope you do too. --Dwight ...vax135!timeinc!dwight ] by Tom Clark, W3IWI Since I've been commissioned to give some formal organization to the Mid-Atlantic Packet Radio Council (MAPRC) I wanted to present some thoughts on how we might go about it. MAPRC is being formed as a formal organization to provide assistance - technical and financial - to the long-haul links in the middle of the EASTNET network. Many of the local digipeaters, BBSs, and other resources are best provided by local groups, but some facilities, particularly the new high-speed 220 MHz links may need some help. It was also pointed out at the last MAPRC meeting that many critical facilities are provided through the efforts of individuals and if they were damaged or lost we'd all be out of luck. What we'd like to do with MAPRC is provide a way to build an efficient network financed by those who use it. MAPRC's principal area of interest was set at the first meeting to be a circle of about 100 miles from the rest stop at which the meetings are held. This takes it down to Washington, out to Harrisburg, and about 1/2 way up New Jersey. This area was chosen purposely because it was well represented at the meeting. No area was to be excluded, but we didn't want to preempt any other group. We'd welcome any group from any area which wanted to work with us. We're going to try to get MAPRC incorporated as a not-for-profit charitable research and educational organization so that contributions would be tax deductible. There is precedent for this - TAPR, AMSAT, and PARA are charitable organizations. This would give some break to those who might contribute money, equipment, sites, etc. We've also discussed types of membership. I proposed two classes - individual and club. Individual members would pay annual dues of something like $20, and would have all operating and voting privileges (although all network resources are now available to all packeteers, this may not continue forever). These would probably be those who are really involved in packet operations and want to have a voice in the development of the network. Club memberships would allow other radio clubs to join and support MAPRC. A club membership would cost the club something like $200 and would allow all members of that club all operating privileges. Individual club members would have no voting rights in MAPRC, however - the club would appoint a representative to MAPRC who would have a single vote. We'd have to limit the size of the club that could join (perhaps to 500 members) to prevent an organization like the ARRL from joining and opening the network to all of its members. I hope to have a MAPRC constitution done in a couple of weeks and I'd like to use a company in Delaware to set things up. This done, we need an interim board of directors to volunteer until the first organizational meeting when the first elected board takes office. Before then I want to make application to the IRS for the tax exemption. That will take a while. Since MAPRC will need the support of the packet community and must respond to its needs, I'd like some comments on this proposal. Otherwise, this is what it's going to look like! -- ----------------------------------------------------------------------------- --Dwight Ernest KA2CNN \ Usenet:...vax135!timeinc!dwight Time Inc. Edit./Prod. Tech. Grp., New York City Voice: (212) 554-5061 \ Compuserve: 70210,523 Telemail: DERNEST/TIMECOMDIV/TIMEINC \ MCI: DERNEST "The opinions expressed above are those of the writer and do not necessarily reflect the opinions of Time Incorporated." -----------------------------------------------------------------------------
dwight@timeinc.UUCP (Dwight Ernest) (08/01/85)
SOME THOUGHTS ON THE PRESENT AND FUTURE OF PACKET RADIO
IN THE MID-ATLANTIC AREA
Tom Clark W3IWI
27 May 1985
A. Introduction:
There has been a lot of discussion the past few months on how we should
develop our packet radio networks in the future and here are some of my
ideas. First let us begin by listing the a priori knowledge that we have:
(1) Packet radio is experiencing an explosive growth. In each of our local
areas in MAPRC (Balto/Wash, Philly/Trenton/SNJ, Harrisburg/York, etc.)
we are seeing several new users pop up each week. The recent entry of
Heath and Kantronics into the commercial market (complete with
unprecedented ad campaigns), plus TAPR's TNC2, plus the series of
articles that are to appear in QST this summer will all act like a
magnet. In May alone, nearly 100 users have logged into the 'IWI BBS
at least once.
(2) Our present networks DO work. The BBS's are serving a communications
need for non-real-time electronic mail (EM) between individuals, as a
focal-point for public discussions ("electronic meetings") and as a
way for users to get help. They are serving as our publishing channel
(why spend $0.22 to mail this to you when I can post it by radio?) so
that the MAPRC confederation hasn't felt the need to start a "paper"
newsletter. Assuming that such communications must extend past the
coverage area of any BBS and it's associated local area network (LAN),
these communications functions REQUIRE linking.
(3) Individual users want to have real-time links available to them too,
whether for "conventional" QSO's or for computer-to-computer
connections. Some users must use a part of the linking network just to
gain access to the local BBS (e.g. the Virginia folks to use 'IWI or
'3Q BBS or APR-5 HF Gateway). A growing number of users from further
away want to use the linking "trunks" to access BBS's outside their
LAN (the BBS DXing syndrome!). Some of the more technical types want
to use the links to test advanced networking concepts before they are
made "public".
(4) The "community" resources which we all enjoy were, for the most part,
installed by individuals and their ultimate control lies with PEOPLE.
There has been precious little community (read that to mean you all)
resources (read that to mean money, hardware, digipeater sites, etc.)
applied to develop the networks.
(5) Technology is rapidly improving -- K9NG has developed 9600 baud modems
which will be available soon. TNC2 is already a reality, albeit still
in a "beta" testing mode. AX.25 Rev.2 code which will fix some "bugs"
is near at hand (it is already available in TNC2 and KA9Q X820 code).
Rudimentary Level 3 (networking) software is running between the BBS's
and certainly will be available for more general use within a year.
W0RLI and his network of linked BBS's continues to enhance their
capabilities daily. KE3Z has developed dual-ported digipeater code.
(6) One of our most valuable resources are the frequencies we use. Most of
the activity is in the 145.01-145.09 range since radio hardware is
easy to obtain. This range is being established nation-wide for packet
use, but in the TMARC area, we only have coordinated three channels
(.01,.03,.05). 220 is not a panacea for curing all future ills for two
reasons -- we may very well lose the band in the next 1 (3,5,??) years
to commercial interests, and radio hardware is not readily available.
Only one channel has been coordinated on 441.0 (where hardware is more
readily available), and hardware is hard to come by on 1270.
Because of all the above, our skeleton system-level resources are being
taxed to the limit. Users thrash with BBS activity on 145.01. People still
continue sending Beacons announcing that they aren't home but their
computer is! New groups want to help by putting up more digipeaters and
BBS's to serve their LAN needs. Is this problem soluble? I think it is, and
here are some of my ideas on HOW.
B. The User and the LAN side of things:
Central to the problem AND the solution is the user and his LAN. My
prediction for the future is that packet radio will evolve towards being a
non-real-time communications service. Industry has already demonstrated
that electronic mail (EM) is the only practical way to tie together diverse
groups that are geographically "spread out". I want to communicate when it
is convenient for ME and I don't want to have to worry about the other
person's schedule. The problem is compounded if multiple people need to
participate in a "meeting" -- N people either have N^2 schedule conflicts
or they have N^2-N separate 2-way discussions -- in either case progress is
retarded.
I see the path towards orderly development involving the concepts of
cellular radio. We have already seen that about 30-50 active users is about
all that a BBS can accommodate without becoming a full-time job for the
SYSOP and without having the individuals "thrash" for BBS access time
(assuming a normal single-user BBS configuration like we have now). [ It is
interesting to note that FM repeater groups have discovered the same thing.
The "super" repeaters with hundreds of users are able to support only brief
call-and-answer communication and usually "spin-off" a new repeater for
every 100 members or so. ] I envision that we will see local-area
"cellular" BBS's springing up to serve LAN needs.
Most, but not all of these will provide their user access on 2M (at 1200
baud) since equipment is cheap and readily available. These "cellular" BBSs
will be QRP since they only need to provide direct access to a small
physical area. They probably do not need to have digipeaters associated
with them unless terrain and similar local conditions dictate. Adjacent
"cells" would have coordinated frequencies so that they don't hear each
other. A theorem in topology states that ANY map can be "painted" in four
colors, with no adjacent areas having matching colors; therefore given a
perfect world, four frequencies should be able to have minimal thrashing
given QRP LAN coverage by all stations. Given my premise that 2M is the LAN
frequency of choice, and the present 145.01-.09 band, these four channels
are .03, .05, .07 and .09 (if we were to choose to enter the 15 vs. 20 khz
repeater war, we could stretch this to provide one more channel by adopting
15 khz spacing).
C. Linking the LAN's:
Nobody wants to "talk" only with people in his own LAN -- that's what
networking is all about. At present EASTNET exists only on 145.01 and
thrashing is occurring because LAN functions go on at the same time as
legitimate network activities. INDIVIDUAL USERS AND NETWORKS "TRUNKS"
CANNOT COEXIST!!
In the evolution of our system, the network should serve to interconnect
the LANs, and the BBS's (or other gateway stations) provide the user
interface into the network. INDIVIDUAL USERS SHOULD NOT ACCESS THE NETWORK
"TRUNKS" DIRECTLY.
Our present networks are fragile and easily broken. If WB2RVX points his
beam north to access WA2SNA, then access thru Mike from APR-6 is marginal;
and Mike is an experimenter at heart -- sometimes his station is doing
other things. A single-point failure at a key site causes us to lose
everything. The present bastardized network using dumb digipeaters requires
end-to-end acknowledgements. Let us assume that a station has a 90%
probability that a given packet will get to the next station, and a 90%
probability of receiving the ack back. Then .9*.9 of his packets = 81% of
his packets will make it thru (with ack) on the first try, and he will have
to retry once out of 5 transmissions. This presents no serious problem
other than the fact that 19% of the channel time is being wasted. However
if 7 hops were needed, then the thruput goes down to 0.9^14 = 22.9% and
only one packet out of 5 makes it the first time! The result -- the channel
is clogged and nothing works. The Level 3 development work is intended to
remove the need for end-to-end acknowledgement. The BBS's right now do this
Level 3 function now in their mail forwarding -- IWI does not attempt to
connect with W0RLI to get stuff to Boston, instead IWI passes the buck by
sending it to WB2MNF, who then worries about the next hop up the coast.
The problem is aggravated if one of the key relay stations is situated in
the midst of heavy LAN activity. Typical local users will be running small
antennas and simply not hear the remote stations at all; the result is that
LAN users on link frequencies kill the link! INDIVIDUAL USERS SHOULD NOT BE
ON LINKING FREQUENCIES!
At present, all we have is .01 (and HF) for linking. The same frequency is
used by users and network gateways. Users also need to access the network
directly since they do not have direct access to the gateways. The solution
seems to me to be to build a second, redundant network in parallel on
different frequencies. This second network should run the highest possible
speeds consistent with reliability and affordability. Right now, the winner
seems to me to be the K9NG 9600 baud design. Hopefully boards will be
available soon. To go along with these modems, we need to begging
implementing multi- (or at least dual-) ported digipeaters; the KE3Z design
based on the venerable X820 board seems to be the logical choice. And we
need to establish a source of good, reliable radios and antennas. It
appears that 220 is the best choice, even considering that 220 is new
"turf" for many of us, and that hardware is harder to find, and that the
FCC might choose to cave in to the commercial interests and pull the band
out from under us. If not 220, then the next place we have to go is 1270,
and that will probably be even a tougher nut to crack since even less
hardware is now available.
The 2M links on .01 should be maintained. For now it is all we have. When
the higher speed links are in place, .01 can serve as an independent
backup. And .01 can be the frequency for individual users to gain access to
the longer-haul links for their own purposes.
D. A Plague on BBS DXing!:
As a special case of the problem just discussed, I want to cite a growing
cancer in our midst -- BBS DXing!! The past couple of months have seen a
large number of new users come on. The links have been improving with the
addition of WA2SNA-2 in NNJ. Here I have seen a growing number of new users
who seem to be unaware of the fragility of EASTNET. The will call in to IWI
with 5-6 hop paths that look like (the call xxx is suppressed to protect
the actual offenders from Bronx cheers!):
xxx <=> WA1IXU <=> KG1O-9 <=> WA2SNA-2 <=> WB2RVX <=> WB4APR-6 <=> W3IWI
Somehow, their one-way connect request packet arrives at IWI and with the
AX.25 handshaking, the BBS send a connect ack and assumes that we are
connected. It then tries to log the person on, and tries again, and again,
and again until the BBS's timers say "Sorry Charlie" and hang up. Then xxx,
having perhaps seen a packet or two coming thru from the BBS sez "Geez,
this is nifty. I think I'll try again" and starts the whole cycle over
again. In a 13 day sampling period in May, of 273 connections logged on the
IWI BBS on 145.01, a total of 96 (=35%) ended with timeouts. INDIVIDUAL
USERS SHOULD NOT ACCESS BBS'S THRU MORE THAN 2-3 DIGIPEATERS!!! BBS's are
there to serve LAN and network gateway functions -- BBS DXING SHOULD BE
BANNED!! I am considering adopting the anti-social solution to this problem
by putting those folks who show up in the "timeout" list onto the "banned
user" list and invite comments on the acceptability of this approach.
E. Getting it all together:
The fragile system we now have was built by individuals as an experiment.
It works! It paves the way for the future. The individuals cannot be
expected to continue to provide ALL the hardware as a gratuity just 'cuz
they are nice guys. The new wave of users who want the services will have
to begin carrying their share of the load. The LAN BBS's and local coverage
digipeaters are the logical province of local clubs and groups. The shared
resource, to which all must contribute is the interconnecting network.
Parts of the network are going to require WORK!!! New sites for key linking
stations have to be acquired AND MAINTAINED. Special hardware -- high speed
modems, multi-port digipeaters, radios, etc. -- all have to be built and
paid for. And the whole network has to be coordinated. I envision the Mid-
Atlantic Packet Radio Council -- MAPRC -- serving that coordination role.
It remains to be seen if that role includes only technical coordination or
if it also will include the financial/managerial functions too. I ask MAPRC
to consider these ideas and begin forging packet radio's future destiny
NOW. If we don't act now, then I feel that we are in danger of having
uncontrolled chaos in the future.
--
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--Dwight Ernest KA2CNN \ Usenet:...vax135!timeinc!dwight
Time Inc. Edit./Prod. Tech. Grp., New York City
Voice: (212) 554-5061 \ Compuserve: 70210,523
Telemail: DERNEST/TIMECOMDIV/TIMEINC \ MCI: DERNEST
"The opinions expressed above are those of the writer and do not necessarily
reflect the opinions of Time Incorporated."
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