----MESSAGE-BEGIN---- <1983080810334600> Return-path: Received: from UDEL-RELAY by SRI-NIC via DDN; 8 Aug 83 11:49:52-PDT Date: Mon, 8 Aug 83 14:33:46 EDT From: Farber Return-Path: Subject: Re: TCP/IP for VMS Received: from udel-ee by udel-relay.ARPA ; 8 Aug 83 14:34:39 EDT (Mon) To: pam%purdue.arpa@udel-ee Cc: tcp-ip%sri-nic.arpa@udel-ee I just got an announcement from Compion urbana Ill 217 384 8500 of a tcp-ip for the vms vax Dave ----MESSAGE-END---- ----MESSAGE-BEGIN---- <1983081613480000> Return-path: Received: from DDN1 by SRI-NIC via DDN; 16 Aug 83 14:52:45-PDT Date: 16 August 1983 17:48 EDT From: Turkewitz @ DDN1 Subject: Thank you, TCP To: TCP-IP @ SRI-NIC CC: Turkewitz @ DDN1 Date: August 16, 1983 Text: Dear TCP designers and implementors, This mailing list must undoubtably be a forum for many TCP discussions, complaints, and bugs. You have probably all heard more than your share about how much slower TCP is than NCP. This, however, is not one of those messages. This is a simple thank-you. I have been working on a TCP/IP connection from Germany over a satellite link back to the United States. Unfortunately, the line has been pretty flakey, and we have had frequent outages. To my amazement, however, I have found out that when we reestablish connection, I can pick up right where I left off! We had one outage that was about 25 minutes long. I was in the middle of composing an electronic mail message at the time the line went down. When it came back up, I was still in the middle of composing the message (not even an interrupt!), and the characters that I had typed between the time that the line went down and the time that I noticed it was down suddenly echoed to me when the line came back up! An associate tells me that this is due to the reliability of TCP. Thank you TCP & all involved. --Ken Turkewitz ----MESSAGE-END---- ----MESSAGE-BEGIN---- <1983082419000000> Return-Path: Received: FROM BRL-VGR BY USC-ISIF.ARPA WITH TCP ; 26 Aug 83 03:46:12 PDT Received: From Brl-Vgr.ARPA by BRL-VGR via smtp; 26 Aug 83 5:39 EDT Sender: Mike Muuss From: TCP-IP@brl To: TCP-IP@brl Date: 25 Aug 1983 00:00 EST Subject: TCP-IP Digest, Vol 2 #13 TCP/IP Digest Thursday, 25 Aug 1983 Volume 2 : Issue 13 Today's Topics: Administrivia && Connecting IBM Mainframes to Foreign Devices TCP/IP from IBM && Looking for TCP/IP to SNA Protocol Gateway BBN TCP has Retransmit-overtaking-Persist Bug Comments on the Parsing of HOSTS.TXT 2 more implementations of TCP/IP for VMS Seeking Portable TCP/IP in Pascal or ADA Information on Omninet hardware ---------------------------------------------------------------------- TCP/IP Digest --- The InterNet Digest LIMITED DISTRIBUTION For Research Use Only --- Not for Public Distribution ---------------------------------------------------------------------- From: Mike Muuss Subject: Administrivia This is the first digest in quite some time, caused by overwork, and slow rate of submissions. There are quite a few interesting topics still left to be discussed, though! One important item which I would like to bring to your attention: For some time now, the NIC has published a much smaller mailing list, on a direct re-transmission basis, which carries the (perhaps unfortunate) name . A great deal of mail directed to that list would be profitably displayed in this Digest as well. The most interesting transmissions to the NIC list I have requested permission from the authors to reprint, and (so far) have always been granted permission. However, this is a tremendous administrative burden on me, and it is no longer my desire to continue with this strategy. Furthermore, a great many people have urged me to automaticly publish all traffic on that list in this digest, as they wish to "keep informed", a request which seems quite justified. Based on a fair quantity of writing with various people, and a good deal of contemplation, I have decided to begin printing excerpts from the NIC TCP-IP (direct) mailing list in the TCP-IP Digest, so that readers of the Digest can stay informed. Please be aware of the fact that messages which get sent to the NIC list *might* be published in the TCP-IP Digest. I will, of course, attempt to be discrete, and will not reprint messages which "obviously" should not receive wider distribution than they already got. Good examples are crassly commercial comments, and random flaming. But, I feel compelled to broadcast solid, technical discussion out to the widest possible audience, to attempt to increase the understanding and acceptance of TCP/IP, and to sensitize computer people to the demands and benefits of inter-operable networks. The subscribers to the NIC list have been notified of this new policy. Please direct your comments on this topic to TCP-IP-REQUEST @ BRL, and I will summarize the response. Best, -Mike Muuss, Moderator ------------------------------ Date: Thursday, 30 Jun 1983 09:29-PDT To: tcp-ip@brl, local-nets@mc Subject: Connecting IBM mainframes to foreign devices From: imagen!cpr%Shasta@su-score There are currently two basic routes to go to connect your IBM mainframe to special devices: the 4300-series DACU, and the Auscom general channel-to-Qbus. ACC also makes an IBM channel attachment for Ethernet which emulates a 327x cluster controller, with individual Ethernet stations corresponding to 3278 tubes or 328x printers. I haven't been able to find out more from ACC, and it sounds like a special-purpose solution, so I won't go into it. For the 4300 series mainframes, IBM is trying very hard to support OEMs and customers with special device-connection requirements, using what they call a DACU (Device Attachment Control Unit), which is basically a fast buffer between a block multiplexor channel on a 4300 and a true Unibus, with an IBM PC (personal computer) as the controlling device. The cost (no OEM pricing yet) is $13,500, without the PC (which only requires a minimal configuration, of a cost around $2500). The contact, Bill Denson (Information Systems Group, Atlanta, 404-238-4710), is extremely helpful and informative. Seems that IBM has finally realized there's money in attaching foreign devices to their mainframes. Auscom is a company in Austin, Texas, whose sole business for years has been making IBM channel attachment devices. The kernel of their interface is a 3-quad-board Qbus set, which they sell alone for about $8k, or packaged in an LSI-11 system with software to drive a whole slew of devices, for about $20k. (Don't believe the prices; talk to them.) The contact is Linda Lewis, 512-836-8080. I'm quite impressed with them; they appear to be the only company making this their entire business, and their customer list is top-notch. For example, they have a standard channel-to-Ethernet (with simple DoD IP-based protocol), emulating an IBM tape drive or line printer, etc. (They use Interlan Ethernet Qbus interfaces.) --Chris Ryland, IMAGEN Corporation ------------------------------ Date: Mon 8 Aug 83 17:57:04-PDT From: Suzanne Johnson Subject: IBM TCP/IP To: tcp-ip@BRL.ARPA My understanding is that although trial versions of IBM TCP/IP are becoming available, IBM has not worked out any method for making a product out of this software. That means that they are not planning a way for a site to arrange for support service other than through (I believe) an expensive contract situation with their Federal Systems Division. It is therefore important that if you are interested in this software, that you have your local IBM rep call the IBM Special Products Group in Chicago and say that they have a customer site interested in a supported version of the software. If the SPG gets 10 or so of these calls, they begin to believe that they need to establish a product related way to handle the software. If only tcp/ip were a bit better known outside of DoD related communities, it might occur to some of the organizations which are implementing internal LANs, and scratching their heads over what protocol to use, that tcp/ip is a natural to consider in this respect. Especially since many LAN's contain many of the mainframe/os combinations currently supported by tcp/ip implementations. Suzanne Johnson ------------------------------ Date: 10 August 1983 09:30 edt From: Vinograd.Multics@mit-multics Subject: TCP/IP-SNA Gateway To: TCP-IP@brl I am looking for any information on a TCP/IP to SNA gateway. What I have in mind is the ability to telnet/FTP to any host on an SNA net, given a physical connection to one host on the SNA net. The reverse access from the SNA net is equally important. SMTP support would be useful, but is not a requirement. Any pointers or rumors of such a capability would be most helpful. Thanks - Dave ------------------------------ Date: 6 Jul 1983 10:53:51 EDT (Wednesday) From: Dennis Rockwell Subject: retransmit overtaking persist bug To: tcp-ip@brl-vgr, tcp-ip@nic, bbn-tcp@bbn-vax There is a bug in the BBN TCP timer code which causes connections with large delays to hang. The symptom is that the sender will continually send single-octet packets which are one octet past the receiver's advertised window. The cause is that the persist timer (used for probing closed windows) was fixed, which the retransmit timer is adaptive (variable). When the persist timer goes off, it resets the retransmit timer. Thus, when the retransmit timer exceeds the persist timer, you hang. The fix is to replace the token T_PERS in tcp_procs.c (about line 250) with tp->t_xmtime*2. This is the only instance of T_PERS except for its definition (which you can delete if you wish). This guarantees that the persist timer is always greater than the retransmit timer. If you know of any system running the BBN software that doesn't receive one of these mailing lists, please inform either them or me. Sorry to send this out to such a wide audience, but this bug will bite more systems as the Internet grows. ------------------------------ Date: 12 Aug 83 15:43:01 BST (Fri) From: Steve Kille To: tcp-ip@brl.arpa cc: robert@ucl-cs Subject: Parsing of hosts.txt We have found a problem which some sites are having with the UCL-CS hosts.txt entry. It appeared in the BBN UNIX software, but this may well not be the only guilty system. 1. Some SMTP sites check the name of a caller against the callers address, thus if you use a multi-homed host for mail under a single name it is useful to put all the addresses in the NIC hosts table. 2. UCL has the facility to route mail over SATNET or IPSS so we use two addresses for UCL-CS (128.16.9.3 the main address and 14.0.0.9) 3. BBN software for SMTP compiles a mail host table from the NIC tables, it sorts any multiple addreses against the host name. Thus HOST : 128.16.9.3, 14.0.0.9 : UCL-CS,UCL :: LOGICAL-HOST : IP,TCP/SMTP : becomes UCL-CS,UCL : 14.0.0.9 : 128.16.9.3, Thats OK, but the mailer only ever uses the first address. The whole point of arranging the addresses in the original table was to cause mailers to try the first address first. 4. Unless some activity at UCL has opened the IPSS tunnel all attempts to reach 14.0.0.9 will fail; because of time zone differences this is quite likely. Thus it looks as though UCL is hardly ever up, and when I complain to people about their mailer, they complain ours is never up. There seems to be an assumption, valid or otherwise, that all Internet paths are either up or down, but never UNI-DIRECTIONAL! Robert Cole + Steve Kille ------------------------------ Date: Wednesday, 27 Jul 1983 09:35-PDT To: tcp-ip@BRL-BMD.ARPA Subject: Re: TCP/IP for VMS From: Chris Kent Kashtan's stuff works and seems to be available from the Wollongong Group. It's full 4.1c networking code. The people at Rice that did the Phoenix Unix under VMS emulator are also reported to have the Berkeley TCP/IP running under their system, but I don't know details. Cheers, chris ------------------------------ Date: 6 Aug 1983 1121-PDT From: LYONS@usc-isi Subject: TCP-IP IN HOL To: TCP-IP@brl cc: LYONS@usc-isi, LYONS@dca-ems I AM INTERESTED IN KNOWING OF HIGH ORDER LANGUAGE IMPLEMENTATIONS OF TCP AND IP WHICH ARE PORTABLE, ESPECIALLY IMPLEMENTATIONS IN PASCAL OR ADA. DO YOU KNOW OF ANY? REGARDS, BOB LYONS/DCEC [ I believe that the CSNET TCP/IP implementation for the IBM was written mostly in PASCAL. There is also a commercial version in PASCAL, for Cybers and other mainframes, mentioned in earlier Digests. -Mike ] ------------------------------ [ This message is reprinted with permission. -Mike ] Date: Wed 27 Jul 83 10:17:39-PDT From: Chris Ryland Subject: Re: request for Omninet vs VAXes info To: local-nets@MIT-MC.ARPA I've been looking into Omninet lately for other reasons, and, as far as I can tell, there isn't much activity with interconnection to VAXes, or, for that matter, with other networks. Omninet DOES have an XNS packet encapsulation protocol, which they and Xerox agreed to (it's published in the Omninet protocol handbook). There is, I believe, a Unibus Omninet board just announced or to be announced, though I can't find the information right now. With that, I suppose you could write a VMS driver for Omninet. For people's information, Omninet seems to be the dominant "cheapo" LAN for the micro world right now (they claim over 20,000 networks, of average size 4 (stations)). It's a 1mb twisted-pair RS422 network, using two proprietary chips (they sell) and a Motorola 6801 (with their custom code burned in) to accomplish the link-level, and little of the transport level. Thus, for the IBM PC, their board is very simple, and low-cost (about $300, I believe), as well as reasonably efficient, as they DMA from the network to waiting buffers in the CPU. It's really a wonderful network from the point of view of cabling: the "transceivers" cost $10, and can be wired by anyone with a screwdriver. 1mb isn't bad for a small cluster of workstations. There are some limitations on the number and type of connections a given workstation can have open: only one "remote disk" connection at a time is allowed, and only three more other connections of non-remote-disk type are allowed simultaneously. /Chris Ryland ------------------------------ END OF TCP-IP DIGEST ******************** ----MESSAGE-END---- ----MESSAGE-BEGIN---- <1983082519000000> Return-Path: Received: FROM BRL-VGR BY USC-ISIF.ARPA WITH TCP ; 26 Aug 83 04:56:36 PDT Received: From Brl-Vgr.ARPA by BRL-VGR via smtp; 26 Aug 83 6:12 EDT Sender: Mike Muuss From: TCP-IP@brl To: TCP-IP@brl Date: 26 Aug 1983 00:00 EST Subject: TCP-IP Digest, Vol 2 #14 TCP/IP Digest Friday, 26 Aug 1983 Volume 2 : Issue 14 Today's Topics: Thank you to TCP -- A testimonial Questions about TCP/IP for Various UNIX Versions 4.2 BSD IEN142 Time Server Available 4.2 BSD UNIX Protocol Violation Discussion Further Details on the MILNET/ARPANET Split ---------------------------------------------------------------------- TCP/IP Digest --- The InterNet Digest LIMITED DISTRIBUTION For Research Use Only --- Not for Public Distribution ---------------------------------------------------------------------- Date: 16 August 1983 17:48 EDT From: Turkewitz@ddn1 Subject: Thank you, TCP To: TCP-IP@brl Dear TCP designers and implementors, This mailing list must undoubtably be a forum for many TCP discussions, complaints, and bugs. You have probably all heard more than your share about how much slower TCP is than NCP. This, however, is not one of those messages. This is a simple thank-you. I have been working on a TCP/IP connection from Germany over a satellite link back to the United States. Unfortunately, the line has been pretty flakey, and we have had frequent outages. To my amazement, however, I have found out that when we reestablish connection, I can pick up right where I left off! We had one outage that was about 25 minutes long. I was in the middle of composing an electronic mail message at the time the line went down. When it came back up, I was still in the middle of composing the message (not even an interrupt!), and the characters that I had typed between the time that the line went down and the time that I noticed it was down suddenly echoed to me when the line came back up! An associate tells me that this is due to the reliability of TCP. Thank you TCP & all involved. --Ken Turkewitz [ Some hosts must have *enormous* values for the retransmit timeouts! -Mike ] ------------------------------ Date: 21 Jul 1983 0906-PDT From: MUEHLEN@sri-csl Subject: UNIX networking To: tcp-ip@brl cc: muehlen@sri-csl We want to start with networking different UNIX Systems (berkeley, bell, xenix, munix) in a local area network (ethernet). Who has done this work and which hardware and software can be recommended? Is there any survey available? Is anybody using UNET or 3COM or Net/One ? Many thanks -Heinz [ 4.2 BSD comes with a TCP/IP that is quite good. Presently, Bell System V does *not* support TCP/IP, but Bell Labs is working on it, under contract to U.S. Army DARCOM. UNET software is also being used by some people, and their latest version is reported to be useable. -Mike ] ------------------------------ Date: Friday, 15 Jul 1983 14:24-PDT To: tcp-ip@Brl Subject: IEN142 time server/user for Berkeley VAX Unix From: Chris Kent Just wanted to let the community know that I've written a network time user/server pair for 4.1cBSD Unix. I have submitted it to Berkeley for inclusion in 4.2, but who knows when they'll finally ship? So if people need it, I'll be happy to send it out. You'll have better luck mailing to me as . Cheers, chris ------------------------------ [ The following 2 messages concern a discussion of an extention to IP which is used by 4.2 BSD UNIX on Ethernets. Bill Shannon's comments on this appeared in the UNIX-WIZARDS mailing list, and I enclose them here to show some of the felings in the UNIX community. -Mike ] Date: Saturday, 20 Aug 1983 16:17-PDT To: tcp-ip@brl Subject: 4.2 Berkeley Unix protocol violation From: imagen!cpr%Shasta@su-score I've brought this up elsewhere (Unix-Wizards), but I thought I might mention it to the TCP/IP world directly. I'm concerned about the Berkeley 4.2 Unix TCP/IP Ethernet implementation, because this version of Unix uses a private encapsulation protocol for IP packets on 10Mbit Ether, in violation of the as-yet-unofficial encapsulation protocol. In detail, the problem is that this TCP implementation uses a non-standard (i.e., an extension of RFC 820) type of IP packet encapsulation in certain circumstances, in an attempt at efficiency improvement (due to Unix internal structures). This happens with no warning, and with no negotation whatsoever with the foreign host. To the foreign host, it simply appears that the connection is hung at the point the private encapsulation is first used. This ``feature'' can be turned off, if you have sources, or are willing to patch the kernel binary image, but this seems like a big mistake on Berkeley's part. Those people trying to supply a product speaking TCP/IP on Ethernet to the 4.2 Unix world are thus forced to either support this extension, or else force the site to turn it off on all their 4.2 machines. Is there an ``official position'' on this type of encapsulation ``violation'' (admittedly by extension)? (Postel? Clark?) /Chris Ryland, IMAGEN ------------------------------ Date: 9 Aug 83 12:54:15-PDT (Tue) To: Unix-Wizards @ Brl-Vgr From: sun!shannon @ Ucb-Vax Subject: Re: 4.2 TCP/IP/Ethernet trailers Philisophically, I don't believe there is anything wrong with the 4.2 TCP/IP Ethernet code, it simply imposes another software layer (the local net encapsulation) between IP and the Ethernet. Practically, I think it is rather unfortunate since it destroys compatibility with the "obvious" implementations of IP on Ethernet. Having some way of negotiating for the use of trailers sounds nice but it also sounds like another software layer which won't be present in the "obvious" implementations. The same sort of problem exists with ARP. Perhaps what is needed is a "standard" for how to implement IP on Ethernet. In the Sun 4.2 system we've made it easy to turn off trailers in the driver, however ARP is mandatory. We may provide a way to "wire down" ARP translations (however the ARP translation table is by nature a cache and therefore small) and I guess it would also be possible to enable trailers based on the destination address. As we start talking to other TCP/IP/Ethernet implementations I suspect we will have to address these problems more directly. Bill Shannon sun!shannon Sun Microsystems, Inc. ------------------------------ Date: 14 Jul 1983 1742-PDT From: NIC@sri-nic Subject: DDN Newsletter No. 28 To: DDN-NEWS-LIST1: ; FURTHER DETAILS ON THE MILNET/ARPANET SPLIT Testing the Logical Split The logical split of the existing ARPANET into the Experimental ARPANET and the MILNET is a major change which requires substantual testing to insure it will be accomplished as an orderly process. ALL HOSTS AND USERS will be impacted. The ARPANET will change from one network into two, and communications with hosts on the other net will require a knowledge of internet procedures. MILNET hosts will use a new network number (Network 26). (Details of procuring updated host tables from the Network Information Center will be covered in a forth- coming newsletter.) The MILNET and the ARPANET will remain connected via five mail bridges (internet gateways augmented with a load-splitting mechanism and an access control filter). The load-splitting mechanism works as follows. Each bridge will contain a table assigning the "default" bridge for each host to use in sending traffic to the other network. If a host sends a message via the wrong bridge and its default bridge is operational, the host will receive an ICMP redirect message telling it which alternate gateway (i.e., default bridge) to use. This mechanism allows the five gateways to balance the internet traffic. After the initial default assignment, if one of the bridges is found to be carrying a disproportionate share of the load, then the host assignment table will be modified. No changes to host software are required. As long as a host supports ICMP, the host-to-gateway protocol, it can make full use of the bridges without knowing its default bridge assignment in advance. A schedule has been developed for testing prior to the actual split. The goals of this testing are to: o Verify the mail bridge load-splitting mechanism and access control filter. o Test host TCP/IP and ICMP implementations. o Test the entire system networkwide. Initial testing will use the testbed environment already available at BBN. BBN has a local ARPANET-clone network, the BBNNET (Network 8), which is connected to the ARPANET via a gateway. During daytime hours the BBNNET passes about 50% as much traffic as does the ARPANET, with the existing gateway passing about 1,000,000 packets during an average day, with about 80,000 packets per hour passing through it during peak hours. This represents a significantly heavier load than will pass through any of the five mail bridges, therefore the BBNNET will provide a realistic test environment. The testing schedule is: 15 June: Two additional gateways between the ARPANET and the BBNNET are installed. 30 June: The gateway load-splitting mechanism is operational. 15 June to 15 August: Gateway load-splitting and routing between the ARPANET and the BBNNET are verified. To aid users in verifying their capabilities to communicate with the MILNET, the first MILNET host to receive net number 26 will be a public news host implemented on a C/70, which will allow anonymous logins and will contain information of general interest to the ARPANET/MILNET community. In addition, to assist TAC users, a TACNEWS service will be provided. By typing "@n" to the TAC, a TAC user will automatically be connected to the public news host wherever it may exist without having to know its actual internet address. Following are some of the major milestones of the Split. 1 July - 1 September: The mail bridges between ARPANET and MILNET are installed. 15 July: The C70 public news host is installed as the first host in the MILNET COI. Also, a second MILNET interface will be added to SRI-NIC. Host managers and technical personnel should now try to connect to the C/70 news host via the mail bridges in order to test their ICMP implementations. 28 July - 2 August: Network technical liaison meetings in: Los Angeles and San Francisco, Cambridge and Washington DC 1 September - 1 October: The NIC maintains the old (ARPANET-only) and the new (ARPANET/MILNET) host tables in parallel. During this period MILNET hosts may voluntarily change to Network No. 26 provided their changeover is coordinated with the NIC to permit timely update of the official host tables. Two full day tests will occur, during which the network will enforce the split, and hosts must use the new host tables. 4 October: The logical split occurs. Network IMPs will enforce the proper COI for each host, and network addressing will be updated to reflect the split. 1 Febuary 1984: Access control filters are implemented in the mail bridges. Although this capability has existed for some time, its implementation is deferred to reduce the problems associated with the logical split on 4 October. ------------------------------ END OF TCP-IP DIGEST ******************** ----MESSAGE-END---- ----MESSAGE-BEGIN---- <1983082601320300> Return-Path: Received: from BRL-VGR by SRI-NIC.ARPA with TCP; Fri 26 Aug 83 02:38:30-PDT Date: Fri, 26 Aug 83 5:32:03 EDT From: Mike Muuss (TCP-IP Digest) To: TCP-IP@sri-nic cc: tcp-ip-request@brl-vgr Subject: NOTE: Automatic Feed to the Digest Based on a fair quantity of writing with various people, and a good deal of contemplation, I have decided to begin printing excerpts from the NIC TCP-IP (direct) mailing list in the TCP-IP Digest, so that readers of the Digest can stay informed. Please be aware of the fact that messages which get sent to the NIC list *might* be published in the TCP-IP Digest. I will, of course, attempt to be discrete, and will not reprint messages which "obviously" should not receive wider distribution than they already got. Good examples are crassly commercial comments, and random flaming. But, I feel compelled to broadcast solid, technical discussion out to the widest possible audience, to attempt to increase the understanding and acceptance of TCP/IP, and to sensitize computer people to the demands and benefits of inter-operable networks. I trust that you will understand. Please send comments on this decision to TCP-IP-REQUEST @ BRL (not NIC). Best, -Mike Muuss TCP/IP Digest Moderator ----MESSAGE-END---- ----MESSAGE-BEGIN---- [632%40brl-bmd.UUCP] <1983082601533600> Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP From: TCP-IP%brl@brl-bmd.UUCP (TCP-IP@brl) Newsgroups: fa.tcp-ip Subject: TCP-IP Digest, Vol 2 #13 Message-ID: <632@brl-bmd.UUCP> Date: Fri, 26-Aug-83 05:53:36 EDT Article-I.D.: brl-bmd.632 Posted: Fri Aug 26 05:53:36 1983 Date-Received: Sat, 3-Sep-83 15:01:24 EDT Lines: 299 TCP/IP Digest Thursday, 25 Aug 1983 Volume 2 : Issue 13 Today's Topics: Administrivia && Connecting IBM Mainframes to Foreign Devices TCP/IP from IBM && Looking for TCP/IP to SNA Protocol Gateway BBN TCP has Retransmit-overtaking-Persist Bug Comments on the Parsing of HOSTS.TXT 2 more implementations of TCP/IP for VMS Seeking Portable TCP/IP in Pascal or ADA Information on Omninet hardware ---------------------------------------------------------------------- TCP/IP Digest --- The InterNet Digest LIMITED DISTRIBUTION For Research Use Only --- Not for Public Distribution ---------------------------------------------------------------------- From: Mike Muuss Subject: Administrivia This is the first digest in quite some time, caused by overwork, and slow rate of submissions. There are quite a few interesting topics still left to be discussed, though! One important item which I would like to bring to your attention: For some time now, the NIC has published a much smaller mailing list, on a direct re-transmission basis, which carries the (perhaps unfortunate) name . A great deal of mail directed to that list would be profitably displayed in this Digest as well. The most interesting transmissions to the NIC list I have requested permission from the authors to reprint, and (so far) have always been granted permission. However, this is a tremendous administrative burden on me, and it is no longer my desire to continue with this strategy. Furthermore, a great many people have urged me to automaticly publish all traffic on that list in this digest, as they wish to "keep informed", a request which seems quite justified. Based on a fair quantity of writing with various people, and a good deal of contemplation, I have decided to begin printing excerpts from the NIC TCP-IP (direct) mailing list in the TCP-IP Digest, so that readers of the Digest can stay informed. Please be aware of the fact that messages which get sent to the NIC list *might* be published in the TCP-IP Digest. I will, of course, attempt to be discrete, and will not reprint messages which "obviously" should not receive wider distribution than they already got. Good examples are crassly commercial comments, and random flaming. But, I feel compelled to broadcast solid, technical discussion out to the widest possible audience, to attempt to increase the understanding and acceptance of TCP/IP, and to sensitize computer people to the demands and benefits of inter-operable networks. The subscribers to the NIC list have been notified of this new policy. Please direct your comments on this topic to TCP-IP-REQUEST @ BRL, and I will summarize the response. Best, -Mike Muuss, Moderator ------------------------------ Date: Thursday, 30 Jun 1983 09:29-PDT To: tcp-ip@brl, local-nets@mc Subject: Connecting IBM mainframes to foreign devices From: imagen!cpr%Shasta@su-score There are currently two basic routes to go to connect your IBM mainframe to special devices: the 4300-series DACU, and the Auscom general channel-to-Qbus. ACC also makes an IBM channel attachment for Ethernet which emulates a 327x cluster controller, with individual Ethernet stations corresponding to 3278 tubes or 328x printers. I haven't been able to find out more from ACC, and it sounds like a special-purpose solution, so I won't go into it. For the 4300 series mainframes, IBM is trying very hard to support OEMs and customers with special device-connection requirements, using what they call a DACU (Device Attachment Control Unit), which is basically a fast buffer between a block multiplexor channel on a 4300 and a true Unibus, with an IBM PC (personal computer) as the controlling device. The cost (no OEM pricing yet) is $13,500, without the PC (which only requires a minimal configuration, of a cost around $2500). The contact, Bill Denson (Information Systems Group, Atlanta, 404-238-4710), is extremely helpful and informative. Seems that IBM has finally realized there's money in attaching foreign devices to their mainframes. Auscom is a company in Austin, Texas, whose sole business for years has been making IBM channel attachment devices. The kernel of their interface is a 3-quad-board Qbus set, which they sell alone for about $8k, or packaged in an LSI-11 system with software to drive a whole slew of devices, for about $20k. (Don't believe the prices; talk to them.) The contact is Linda Lewis, 512-836-8080. I'm quite impressed with them; they appear to be the only company making this their entire business, and their customer list is top-notch. For example, they have a standard channel-to-Ethernet (with simple DoD IP-based protocol), emulating an IBM tape drive or line printer, etc. (They use Interlan Ethernet Qbus interfaces.) --Chris Ryland, IMAGEN Corporation ------------------------------ Date: Mon 8 Aug 83 17:57:04-PDT From: Suzanne Johnson Subject: IBM TCP/IP To: tcp-ip@BRL.ARPA My understanding is that although trial versions of IBM TCP/IP are becoming available, IBM has not worked out any method for making a product out of this software. That means that they are not planning a way for a site to arrange for support service other than through (I believe) an expensive contract situation with their Federal Systems Division. It is therefore important that if you are interested in this software, that you have your local IBM rep call the IBM Special Products Group in Chicago and say that they have a customer site interested in a supported version of the software. If the SPG gets 10 or so of these calls, they begin to believe that they need to establish a product related way to handle the software. If only tcp/ip were a bit better known outside of DoD related communities, it might occur to some of the organizations which are implementing internal LANs, and scratching their heads over what protocol to use, that tcp/ip is a natural to consider in this respect. Especially since many LAN's contain many of the mainframe/os combinations currently supported by tcp/ip implementations. Suzanne Johnson ------------------------------ Date: 10 August 1983 09:30 edt From: Vinograd.Multics@mit-multics Subject: TCP/IP-SNA Gateway To: TCP-IP@brl I am looking for any information on a TCP/IP to SNA gateway. What I have in mind is the ability to telnet/FTP to any host on an SNA net, given a physical connection to one host on the SNA net. The reverse access from the SNA net is equally important. SMTP support would be useful, but is not a requirement. Any pointers or rumors of such a capability would be most helpful. Thanks - Dave ------------------------------ Date: 6 Jul 1983 10:53:51 EDT (Wednesday) From: Dennis Rockwell Subject: retransmit overtaking persist bug To: tcp-ip@brl-vgr, tcp-ip@nic, bbn-tcp@bbn-vax There is a bug in the BBN TCP timer code which causes connections with large delays to hang. The symptom is that the sender will continually send single-octet packets which are one octet past the receiver's advertised window. The cause is that the persist timer (used for probing closed windows) was fixed, which the retransmit timer is adaptive (variable). When the persist timer goes off, it resets the retransmit timer. Thus, when the retransmit timer exceeds the persist timer, you hang. The fix is to replace the token T_PERS in tcp_procs.c (about line 250) with tp->t_xmtime*2. This is the only instance of T_PERS except for its definition (which you can delete if you wish). This guarantees that the persist timer is always greater than the retransmit timer. If you know of any system running the BBN software that doesn't receive one of these mailing lists, please inform either them or me. Sorry to send this out to such a wide audience, but this bug will bite more systems as the Internet grows. ------------------------------ Date: 12 Aug 83 15:43:01 BST (Fri) From: Steve Kille To: tcp-ip@brl.arpa cc: robert@ucl-cs Subject: Parsing of hosts.txt We have found a problem which some sites are having with the UCL-CS hosts.txt entry. It appeared in the BBN UNIX software, but this may well not be the only guilty system. 1. Some SMTP sites check the name of a caller against the callers address, thus if you use a multi-homed host for mail under a single name it is useful to put all the addresses in the NIC hosts table. 2. UCL has the facility to route mail over SATNET or IPSS so we use two addresses for UCL-CS (128.16.9.3 the main address and 14.0.0.9) 3. BBN software for SMTP compiles a mail host table from the NIC tables, it sorts any multiple addreses against the host name. Thus HOST : 128.16.9.3, 14.0.0.9 : UCL-CS,UCL :: LOGICAL-HOST : IP,TCP/SMTP : becomes UCL-CS,UCL : 14.0.0.9 : 128.16.9.3, Thats OK, but the mailer only ever uses the first address. The whole point of arranging the addresses in the original table was to cause mailers to try the first address first. 4. Unless some activity at UCL has opened the IPSS tunnel all attempts to reach 14.0.0.9 will fail; because of time zone differences this is quite likely. Thus it looks as though UCL is hardly ever up, and when I complain to people about their mailer, they complain ours is never up. There seems to be an assumption, valid or otherwise, that all Internet paths are either up or down, but never UNI-DIRECTIONAL! Robert Cole + Steve Kille ------------------------------ Date: Wednesday, 27 Jul 1983 09:35-PDT To: tcp-ip@BRL-BMD.ARPA Subject: Re: TCP/IP for VMS From: Chris Kent Kashtan's stuff works and seems to be available from the Wollongong Group. It's full 4.1c networking code. The people at Rice that did the Phoenix Unix under VMS emulator are also reported to have the Berkeley TCP/IP running under their system, but I don't know details. Cheers, chris ------------------------------ Date: 6 Aug 1983 1121-PDT From: LYONS@usc-isi Subject: TCP-IP IN HOL To: TCP-IP@brl cc: LYONS@usc-isi, LYONS@dca-ems I AM INTERESTED IN KNOWING OF HIGH ORDER LANGUAGE IMPLEMENTATIONS OF TCP AND IP WHICH ARE PORTABLE, ESPECIALLY IMPLEMENTATIONS IN PASCAL OR ADA. DO YOU KNOW OF ANY? REGARDS, BOB LYONS/DCEC [ I believe that the CSNET TCP/IP implementation for the IBM was written mostly in PASCAL. There is also a commercial version in PASCAL, for Cybers and other mainframes, mentioned in earlier Digests. -Mike ] ------------------------------ [ This message is reprinted with permission. -Mike ] Date: Wed 27 Jul 83 10:17:39-PDT From: Chris Ryland Subject: Re: request for Omninet vs VAXes info To: local-nets@MIT-MC.ARPA I've been looking into Omninet lately for other reasons, and, as far as I can tell, there isn't much activity with interconnection to VAXes, or, for that matter, with other networks. Omninet DOES have an XNS packet encapsulation protocol, which they and Xerox agreed to (it's published in the Omninet protocol handbook). There is, I believe, a Unibus Omninet board just announced or to be announced, though I can't find the information right now. With that, I suppose you could write a VMS driver for Omninet. For people's information, Omninet seems to be the dominant "cheapo" LAN for the micro world right now (they claim over 20,000 networks, of average size 4 (stations)). It's a 1mb twisted-pair RS422 network, using two proprietary chips (they sell) and a Motorola 6801 (with their custom code burned in) to accomplish the link-level, and little of the transport level. Thus, for the IBM PC, their board is very simple, and low-cost (about $300, I believe), as well as reasonably efficient, as they DMA from the network to waiting buffers in the CPU. It's really a wonderful network from the point of view of cabling: the "transceivers" cost $10, and can be wired by anyone with a screwdriver. 1mb isn't bad for a small cluster of workstations. There are some limitations on the number and type of connections a given workstation can have open: only one "remote disk" connection at a time is allowed, and only three more other connections of non-remote-disk type are allowed simultaneously. /Chris Ryland ------------------------------ END OF TCP-IP DIGEST ******************** ----MESSAGE-END---- ----MESSAGE-BEGIN---- [633%40brl-bmd.UUCP] <1983082602251800> Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP From: TCP-IP%brl@brl-bmd.UUCP (TCP-IP@brl) Newsgroups: fa.tcp-ip Subject: TCP-IP Digest, Vol 2 #14 Message-ID: <633@brl-bmd.UUCP> Date: Fri, 26-Aug-83 06:25:18 EDT Article-I.D.: brl-bmd.633 Posted: Fri Aug 26 06:25:18 1983 Date-Received: Sat, 3-Sep-83 15:16:05 EDT Lines: 265 TCP/IP Digest Friday, 26 Aug 1983 Volume 2 : Issue 14 Today's Topics: Thank you to TCP -- A testimonial Questions about TCP/IP for Various UNIX Versions 4.2 BSD IEN142 Time Server Available 4.2 BSD UNIX Protocol Violation Discussion Further Details on the MILNET/ARPANET Split ---------------------------------------------------------------------- TCP/IP Digest --- The InterNet Digest LIMITED DISTRIBUTION For Research Use Only --- Not for Public Distribution ---------------------------------------------------------------------- Date: 16 August 1983 17:48 EDT From: Turkewitz@ddn1 Subject: Thank you, TCP To: TCP-IP@brl Dear TCP designers and implementors, This mailing list must undoubtably be a forum for many TCP discussions, complaints, and bugs. You have probably all heard more than your share about how much slower TCP is than NCP. This, however, is not one of those messages. This is a simple thank-you. I have been working on a TCP/IP connection from Germany over a satellite link back to the United States. Unfortunately, the line has been pretty flakey, and we have had frequent outages. To my amazement, however, I have found out that when we reestablish connection, I can pick up right where I left off! We had one outage that was about 25 minutes long. I was in the middle of composing an electronic mail message at the time the line went down. When it came back up, I was still in the middle of composing the message (not even an interrupt!), and the characters that I had typed between the time that the line went down and the time that I noticed it was down suddenly echoed to me when the line came back up! An associate tells me that this is due to the reliability of TCP. Thank you TCP & all involved. --Ken Turkewitz [ Some hosts must have *enormous* values for the retransmit timeouts! -Mike ] ------------------------------ Date: 21 Jul 1983 0906-PDT From: MUEHLEN@sri-csl Subject: UNIX networking To: tcp-ip@brl cc: muehlen@sri-csl We want to start with networking different UNIX Systems (berkeley, bell, xenix, munix) in a local area network (ethernet). Who has done this work and which hardware and software can be recommended? Is there any survey available? Is anybody using UNET or 3COM or Net/One ? Many thanks -Heinz [ 4.2 BSD comes with a TCP/IP that is quite good. Presently, Bell System V does *not* support TCP/IP, but Bell Labs is working on it, under contract to U.S. Army DARCOM. UNET software is also being used by some people, and their latest version is reported to be useable. -Mike ] ------------------------------ Date: Friday, 15 Jul 1983 14:24-PDT To: tcp-ip@Brl Subject: IEN142 time server/user for Berkeley VAX Unix From: Chris Kent Just wanted to let the community know that I've written a network time user/server pair for 4.1cBSD Unix. I have submitted it to Berkeley for inclusion in 4.2, but who knows when they'll finally ship? So if people need it, I'll be happy to send it out. You'll have better luck mailing to me as . Cheers, chris ------------------------------ [ The following 2 messages concern a discussion of an extention to IP which is used by 4.2 BSD UNIX on Ethernets. Bill Shannon's comments on this appeared in the UNIX-WIZARDS mailing list, and I enclose them here to show some of the felings in the UNIX community. -Mike ] Date: Saturday, 20 Aug 1983 16:17-PDT To: tcp-ip@brl Subject: 4.2 Berkeley Unix protocol violation From: imagen!cpr%Shasta@su-score I've brought this up elsewhere (Unix-Wizards), but I thought I might mention it to the TCP/IP world directly. I'm concerned about the Berkeley 4.2 Unix TCP/IP Ethernet implementation, because this version of Unix uses a private encapsulation protocol for IP packets on 10Mbit Ether, in violation of the as-yet-unofficial encapsulation protocol. In detail, the problem is that this TCP implementation uses a non-standard (i.e., an extension of RFC 820) type of IP packet encapsulation in certain circumstances, in an attempt at efficiency improvement (due to Unix internal structures). This happens with no warning, and with no negotation whatsoever with the foreign host. To the foreign host, it simply appears that the connection is hung at the point the private encapsulation is first used. This ``feature'' can be turned off, if you have sources, or are willing to patch the kernel binary image, but this seems like a big mistake on Berkeley's part. Those people trying to supply a product speaking TCP/IP on Ethernet to the 4.2 Unix world are thus forced to either support this extension, or else force the site to turn it off on all their 4.2 machines. Is there an ``official position'' on this type of encapsulation ``violation'' (admittedly by extension)? (Postel? Clark?) /Chris Ryland, IMAGEN ------------------------------ Date: 9 Aug 83 12:54:15-PDT (Tue) To: Unix-Wizards @ Brl-Vgr From: sun!shannon @ Ucb-Vax Subject: Re: 4.2 TCP/IP/Ethernet trailers Philisophically, I don't believe there is anything wrong with the 4.2 TCP/IP Ethernet code, it simply imposes another software layer (the local net encapsulation) between IP and the Ethernet. Practically, I think it is rather unfortunate since it destroys compatibility with the "obvious" implementations of IP on Ethernet. Having some way of negotiating for the use of trailers sounds nice but it also sounds like another software layer which won't be present in the "obvious" implementations. The same sort of problem exists with ARP. Perhaps what is needed is a "standard" for how to implement IP on Ethernet. In the Sun 4.2 system we've made it easy to turn off trailers in the driver, however ARP is mandatory. We may provide a way to "wire down" ARP translations (however the ARP translation table is by nature a cache and therefore small) and I guess it would also be possible to enable trailers based on the destination address. As we start talking to other TCP/IP/Ethernet implementations I suspect we will have to address these problems more directly. Bill Shannon sun!shannon Sun Microsystems, Inc. ------------------------------ Date: 14 Jul 1983 1742-PDT From: NIC@sri-nic Subject: DDN Newsletter No. 28 To: DDN-NEWS-LIST1: ; FURTHER DETAILS ON THE MILNET/ARPANET SPLIT Testing the Logical Split The logical split of the existing ARPANET into the Experimental ARPANET and the MILNET is a major change which requires substantual testing to insure it will be accomplished as an orderly process. ALL HOSTS AND USERS will be impacted. The ARPANET will change from one network into two, and communications with hosts on the other net will require a knowledge of internet procedures. MILNET hosts will use a new network number (Network 26). (Details of procuring updated host tables from the Network Information Center will be covered in a forth- coming newsletter.) The MILNET and the ARPANET will remain connected via five mail bridges (internet gateways augmented with a load-splitting mechanism and an access control filter). The load-splitting mechanism works as follows. Each bridge will contain a table assigning the "default" bridge for each host to use in sending traffic to the other network. If a host sends a message via the wrong bridge and its default bridge is operational, the host will receive an ICMP redirect message telling it which alternate gateway (i.e., default bridge) to use. This mechanism allows the five gateways to balance the internet traffic. After the initial default assignment, if one of the bridges is found to be carrying a disproportionate share of the load, then the host assignment table will be modified. No changes to host software are required. As long as a host supports ICMP, the host-to-gateway protocol, it can make full use of the bridges without knowing its default bridge assignment in advance. A schedule has been developed for testing prior to the actual split. The goals of this testing are to: o Verify the mail bridge load-splitting mechanism and access control filter. o Test host TCP/IP and ICMP implementations. o Test the entire system networkwide. Initial testing will use the testbed environment already available at BBN. BBN has a local ARPANET-clone network, the BBNNET (Network 8), which is connected to the ARPANET via a gateway. During daytime hours the BBNNET passes about 50% as much traffic as does the ARPANET, with the existing gateway passing about 1,000,000 packets during an average day, with about 80,000 packets per hour passing through it during peak hours. This represents a significantly heavier load than will pass through any of the five mail bridges, therefore the BBNNET will provide a realistic test environment. The testing schedule is: 15 June: Two additional gateways between the ARPANET and the BBNNET are installed. 30 June: The gateway load-splitting mechanism is operational. 15 June to 15 August: Gateway load-splitting and routing between the ARPANET and the BBNNET are verified. To aid users in verifying their capabilities to communicate with the MILNET, the first MILNET host to receive net number 26 will be a public news host implemented on a C/70, which will allow anonymous logins and will contain information of general interest to the ARPANET/MILNET community. In addition, to assist TAC users, a TACNEWS service will be provided. By typing "@n" to the TAC, a TAC user will automatically be connected to the public news host wherever it may exist without having to know its actual internet address. Following are some of the major milestones of the Split. 1 July - 1 September: The mail bridges between ARPANET and MILNET are installed. 15 July: The C70 public news host is installed as the first host in the MILNET COI. Also, a second MILNET interface will be added to SRI-NIC. Host managers and technical personnel should now try to connect to the C/70 news host via the mail bridges in order to test their ICMP implementations. 28 July - 2 August: Network technical liaison meetings in: Los Angeles and San Francisco, Cambridge and Washington DC 1 September - 1 October: The NIC maintains the old (ARPANET-only) and the new (ARPANET/MILNET) host tables in parallel. During this period MILNET hosts may voluntarily change to Network No. 26 provided their changeover is coordinated with the NIC to permit timely update of the official host tables. Two full day tests will occur, during which the network will enforce the split, and hosts must use the new host tables. 4 October: The logical split occurs. Network IMPs will enforce the proper COI for each host, and network addressing will be updated to reflect the split. 1 Febuary 1984: Access control filters are implemented in the mail bridges. Although this capability has existed for some time, its implementation is deferred to reduce the problems associated with the logical split on 4 October. ------------------------------ END OF TCP-IP DIGEST ******************** ----MESSAGE-END----