n2dsy@hou2d.UUCP (G.BEATTIE) (12/15/87)
The Radio Amateur Telecommuications Society
Information Bulletin
COSI-Switch Update: 13 December 1987
* Well December is here we're on track ! As stated in our last update
we are running a few weeks behind, but we haven't gotten any more
behind than before !
* Tom, W2VY has the code in the initial Z-80 target machine
(TNC-2) and has begun the debugging process. He has previously
completed an exhaustive set of software and protocol tests on a PC and
on a Z-80 based CP/M machine. The protocol tests, test the whole system
with the exception of the drivers. The early versions of the test
environment were loaded to CompuServe and are available there.
* Beta Testing will begin this month (December).
* The RATS COSI-Switch by Thomas A. Moulton, W2VY will be released
(mailed, uploaded, etc) with source in late January. Target machines
for this release include the TNC-2 family and PAC-COMM's DR-200 and PC-100.
Other targets are being examined...feel free to suggest a favorite !
* RATS is expecting the arrival of a beta test PC-186 board. The RATS
COSI-Switch will be ported to this device, providing a vehicle for
high speed (greater than 56KBps) links.
* The COSI-Switch software has been requested by groups in 33+ states and
15+ countries !
* The back to back multi-TNC node configurations will be supported
for those who wish to change their node software. PLEASE NOTE:
This was requested by YOU, the folks who expressed a desire run software
with available source code.
* There have been some questions about our distribution and use policies.
Our software policy is simple:
1. Free for non-commercial Amateur Radio use ONLY,
2. Modification policy for non-commercial Amateur Radio users is simple,
3. Executable, source and modification licenses can be obtained
for other uses.
Software modification policy for non-commercial Amateur Radio users: You can
modify the code all you want, but in order to maintain your right
to use the code you must send us copies of your modified software source.
This ensures that the distribution of new features added by others
is consistent. It also helps us ferret out bug reports from the field.
******* PLEASE NOTE: ALL PROCEEDS GO TOWARD NETWORK COMPONENTS ********
NO CONVENTION TRAVEL FROM THIS FUND !
* Here is a description of some of the features
*** AS IMPLEMENTED in the SWITCH TODAY.
USER CAPABILITIES
The interface to the COSI-Switch has been designed with the
average user in mind. Current users are familiar with
networking using digipeaters (C CALLSIGN VIA DIGI, DIGI). We
have continued this basic concept in the COSI user interface.
There are several different ways the user can access the switch
and, through it, the network.
Local Digipeating
----- -----------
This mode of operation is pretty straightforward and provides a
familiar mode of operation to continue WITHIN the local network.
The COSI-Switch will ONLY digipeat frames with just one callsign (its own)
in the "via" field of the AX.25 frame.
Within the local network, users may digipeat through the switch by typing:
"C N2FWI V N2DSY-3"
Multi-Switch Networking
------------ ----------
There is only one new concept for users to learn in order to use the advanced,
multi-switch networking capabilities of the COSI-Switch. Each switch has a
unique, 6-digit "address." This address is made up of two parts: the telephone
area code serving the switch's location (first three digits), and a three digit
Switch Number.
In order to connect to another station at a remote switch one must know the
address for that switch. If KB7UV uses the switch "718010" then to connect
to him a user would type:
"C KB7UV V N2DSY-3,718010"
The call request will be routed TRANSPARENTLY to the destination
switch and user.
Local Switching
----- ---------
There is however another option: a user may want to use the advanced
functionality of the switch WITHIN the local network. This is just like a
multi-switch connection except the Destination Switch Address is that of
Source Switch! To do this type:
"C N2FWI V N2DSY-3,201010"
This initially looks like a two hop digipeater connection, but in reality
the COSI-Switch gets into the picture and make the connection more
reliable. The COSI-Switch will receive the request from W2XYZ and then
send a connect to N2FWI. After this connection is established the switch
will acknowledge the initial connect request. If required, the N2DSY-3
switch will retransmit frames that are unacknowledged. The switch will
use its own parameters to determine the need and ideal opportunity to
retransmit. The switch will not only automatically determine the port
used by "known" users, but will search out the "unknown" user on its user
ports.
Network Management
------- ----------
After examining the trends of the last few years, we have determined that most
switches, digipeaters and other devices seem to be fairly stable. We have
chosen to build on this and plan our network implementation philosophy
on the premise that inter-switch trunks will be planned and preconfigured.
This reduces the need to endlessly tie-up precious bandwidth with automatic
reconfiguration tables. This also has the additional advantage of preventing
renegade nodes from appearing and jeopardizing the operational effectiveness
of the backbone. This brings up two points:
1. How will the COSI-Switches be managed ?
The COSI-Switch when released, will contain a remote configuration and
statistics module. This system will have a security mechanism. Another
capability of the COSI-Switch is the generation of "connection records".
These provide an record for the COSI-Switch owner/trustee of the source, and
destination calls and network addresses, access digipeater path (if any), the
time and whether the record is a call or a clear record. The clear records
will also contain the clearing cause and diagnostic code. These are valuable
items which aid in the network configuration process. They are also useful
when attempting to track down the source of undesirable activity.
2. How will temporary COSI-Switches be added in times of emergency when
a stricken area requires supplemental communications ?
A COSI-Switch may be added to the network at any time. The new switch
located in the stricken area would appear as a Level 3 user. Calls would
be routed out by the new switch and through any switches attached to it.
Inbound calls would not be routed into the stricken area until, or unless
the new switch is added to the tables of the existing switches. This is
an IDEAL situation since emergency traffic should flow outbound from the
stricken area, until the situation has stablized. The remote configuration
feature can be used to integrate the new switch into the network if the
situation requires.
The procedure and format of the remote configuration are currently being
finalized.
Addressing Plan
---------- ----
The Level 2 user can be found in the network by routing on the
destination user's callsign and the destination node address. A
short form entry mechanism has been provided for Level 2 TNC
users. This is the six digit switch number made up of the
telephone area code and switch number. This is a part of a
larger (20+ character) address. Don't expect us to ask you the
users to type in all this, but if you wish to have full
interworking between networks (Amateur and others) then you
might want the option for some connections. We'll talk about
this in further bulletins. Here's a brief overview to get you
started.
The addressing plan used by the COSI-Switches is based on the
OSI NSAP Address (Open Systems Interconnection - Network Service
Access Point). This address contains two components: the
callsign of the station and the COSI-Switch Address. The NSAP
takes the form: Prefix + callsign + Data Country Code + Number
The Prefix is determined jointly by CCITT and ISO. It functions
to identify the portion of the addressing plan that we are
using. The next field contains the Amateur callsign.
The last two field identify the country of operation and the switch
address. Specific plans for national use outside of North America
will be developed. Consultation with RATS is suggested so that we can
include such plans in our documentation.
Final Note
----- ----
We will be circulating switch software to the beta group later
in the month and general distribution will be in late January.
Despite some recent questions about commercial systems, we are
investigating through letter the possibility of distributing the
COSI-Switch software via CompuServe. Planned channels are via
telephone BBS, UUCP, US Mail, and Amateur Packet Networks Look
for it.
73, J. Gordon Beattie, Jr. N2DSY @ KD6TH or ihnp4!hotps!n2dsy-4!n2dsy
Telephone: 201-387-8896tom@tsdiag.UUCP (12/17/87)
I just want to add that you will notice that the addressing described for COSI referenced Area Code and Switch number, Gordon and I fought over this a bit. Why? Everything listed is CODED AND WORKING unless otherwise stated. We will be using Area Codes and Exchanges in future releases but I was very firm on having the update notice reflect REALITY not what we want to have in for the first release. It's just a matter of coding to get the ideal things in place. The beta release will use switch numbers, I HOPE to have exchanges in for the offical release in Jan. hi ho hi ho it's off to code we go... -- Thomas A. Moulton, W2VY Life is too short to be mad about things. Home: (201) 779-W2VY Packet: w2vy@kd6th Voice: 145.190 (r) Work: (201) 492-4880 x3226 FAX: (201) 493-9167 Concurrent Computer Corp. uucp: ...!ihnp4!hotps!ka2qhd!w2vy