rdp@pbseps.UUCP (Richard Perlman) (02/07/89)
We are looking for an x.25 Server for a TCP/IP ethernet. The
major use for the x.25 in this case is as a circuit switch.
(It will replace several async lines to a nearby PAD from an
Encore ANNEX terminal server).
The server should be able to extend virtual sessions to hosts on the
local ethernet by telnet or similar protocol.
It would also be nice to be able to use the x.25 server as a
TCP/IP gateway between a local UNIX host and some distant
network.
Any ideas, specific vendor/product sugestions or otherwise are
welcome.
--
Richard Perlman * pbseps!rdp@PacBell.COM || {ames,sun,att}!pacbell!pbseps!rdp
180 New Montgomery St. rm 602, San Francisco, CA 94105 |*| 1(415) 545-0233hedrick@geneva.rutgers.edu (Charles Hedrick) (02/07/89)
You ask about X.25 to TCP/IP services. We are currently doing an experiment with cisco equipment to provide just the sort of service you asked for. I don't think it is a product yet, but you might call them and ask about availability. (I can give you a specific contact if you have trouble getting information). We have a 56K line to NJ Bell's public X.25 network. People use NJ Bell pads to connect to us. This gets them to the cisco gateway. It gives them a normal cisco terminal server prompt. From there they can telnet or rlogin to any system on our network. There are also plans to have them make the connection transparently, based on a mapping from X.121 addresses to IP addresses, so users don't have to go through the extra step of talking to the cisco command level. However we have so many hosts on our network that I don't want to have to keep NJ Bell up to date on all of our addresses. Thus we have no plans to use such a feature even if it exists. cisco has the ability to forward IP packets to another gateway over X.25 connections. This is used for DDN X.25, as well as for X.25 based private networks, so this is a real product. (They can also handle DECnet and probably other things over X.25 links.) They is also an experiment at another university with outgoing TCP/IP to pad service. That is, you make a telnet connection to their box and it turns it into an outgoing X.25 call. Again, I believe that it is an experiment and not a product. At this point the pad to telnet code seems to be solid. However it's hard to be sure. We get lots of unexplained wierd events. As far as I can tell, they are all the fault of the X.25 network, but it's hard to be sure. They are all associated with some clear or other thing that NJ Bell sends us. They have reason codes suggesting that something is wrong on the network (though it's hard to be sure how much to trust reason codes with an X.25 network that uses "out of order" as the reason code in a normal close). It sounded to us like a great idea to use a public X.25 network for communications around the state. (We have a group that supplies services to state colleges.) Unfortunately, I'm not convinced that we can afford to use it in any large-scale way. X.25 seems to be priced for interactive transaction processing, where every minute or so a user with a block-mode terminal sends a couple of new values for a field and gets a few updates back. If you try to use it for something like a news feed, the packet charges kill you. It is cheaper to put in a dedicated line. Of course maybe if you are with the phone company, this isn't an issue for you. Our theory is that this is why the Internet doesn't use X.25 more than it does.
dnwcv@dcatla.UUCP (William C. VerSteeg) (02/10/89)
As long as everyone is using this opportunity to get a plug in, here comes DCA's plug. DCA offers a product that has both a telnet (TCP/IP) terminal server and a telenet (X25) PAD in the same box. It also has some user validation capabilities that are useful in a security concious environment. This product has been available for about a year and is pretty stable. I won't crassly flood the net with a long commercial. Please contact Ken Davis at 404-442-4156 for more information. Bill VerSteeg
bct@lfcs.ed.ac.uk (Brian Tompsett) (02/13/89)
In article <333@pbseps.UUCP> rdp@pbseps.PacBell.COM (Richard Perlman) writes: >We are looking for an x.25 Server for a TCP/IP ethernet. [...] > >It would also be nice to be able to use the x.25 server as a >TCP/IP gateway between a local UNIX host and some distant >network. You should look at boxes made by Spider. They specialise in this kind of product. Some literature just arrived on my desk this morning about a TCP/IP router via X.25. They also do X.25 WAN to X.25 LAN via ether boxes and all kinds of other goodies. They have an office in Burlington Mass. (617 270 3510). We have an X.25/Ether gateway here and it acts as the X.25 gate for 6 or so main frames. Seems to work OK. Brian. > Brian Tompsett. Department of Computer Science, University of Edinburgh, > JCMB, The King's Buildings, Mayfield Road, EDINBURGH, EH9 3JZ, Scotland, U.K. > Telephone: +44 31 667 1081 x2711. > JANET: bct@uk.ac.ed.ecsvax ARPA: bct%ed.ecsvax@nss.cs.ucl.ac.uk
ccruss@deneb.ucdavis.edu (0059;0000000000;230;9999;98;) (02/17/89)
We have been using a Develcon Develnet that has x.25 to tcp/ip
capabilities. In addition to connecting all of our async terminals and
host ports, we have x.25 connections to our Unisys A10. Each of the four
64kb x.25 circuits to the A10 supports 48 vertual connections. We also
have the Develnet terminal server board installed. This board supports
64 telnet sessions to our campus TCP/IP network. Connections can be made
in any of the directions between any of the protocols. We have been
running this equipment for about a year and a half.
I believe that Develcon also markets a box that does just x.25 to telnet
service as well.
Russ
Russell Hobby
Data Communications Manager
U. C. Davis
Computing Services BITNET: RDHOBBY@UCDAVIS
Davis Ca 95616 UUCP: ...!ucbvax!ucdavis!rdhobby
(916) 752-0236 INTERNET: rdhobby@ucdavis.edu