Alan.Gallatin@samba.acs.unc.edu (Alan Gallatin) (03/27/91)
I've been told by several people that there is a way (ways?) to send TCP/IP packets over a modem thereby allowing an IBM (such as my 386) which has no ethernet access to the internet to run such utilities as telnet, ftp, etc. I would be MOST GRATEFUL for answers to the following: 1) Is there any truth to what I've heard? Can I run TCP/IP over a modem? 2) Aside from speed, what differences will I notice between this implementation and an "ethernet-ed" IBM running "TELBIN / TN3270" and "FTP"? 3) What software do I need and what's the installation process like? 4) Do I need the cooperation of a current internet machine for me to access the internet and, if so, what does that machine need to provide me with? 5) Do I need any TECHNICAL knowledge of TCP/IP packet structure, ethernet, internet, etc. or is a good working knowledge of IBM and internet USAGE sufficient? 6) Do I really want to do this???? (Don't bother answering this one - the questions above are what I really need!) Thanks MUCH! Alan -- ============================================================================= Extended Bulletin Board Service, Research & Development Office of Information Technology, University of North Carolina at Chapel Hill internet: bbs.acs.unc.edu or 128.109.157.30
nelson@sun.soe.clarkson.edu (Russ Nelson) (03/27/91)
In article <3108@beguine.UUCP> Alan.Gallatin@samba.acs.unc.edu (Alan Gallatin) writes:
I've been told by several people that there is a way (ways?) to send
TCP/IP packets over a modem thereby allowing an IBM (such as my 386)
which has no ethernet access to the internet to run such utilities as
telnet, ftp, etc. I would be MOST GRATEFUL for answers to the
following:
1) Is there any truth to what I've heard? Can I run TCP/IP over a
modem?
Yes. You can do TCP/IP over *any* medium, even carrier pigeon.
In fact, I believe there is even an RFC describing how to do it.
There are two standard protocls for transporting TCP/IP packets
over a serial link: SLIP and PPP.
2) Aside from speed, what differences will I notice between this
implementation and an "ethernet-ed" IBM running "TELBIN / TN3270" and
"FTP"?
None.
3) What software do I need and what's the installation process like?
You need a TCP/IP package that can communicate using SLIP or PPP.
For example, MIT's PC-IP package can use SLIP.
4) Do I need the cooperation of a current internet machine for me to
access the internet and, if so, what does that machine need to provide
me with?
They need to set up a router that can use SLIP (or PPP). The cheapest
way to do this is using Phil Karn's (KA9Q) NOS. The only hitch with it
is that only educational or amateur radio users can use it.
5) Do I need any TECHNICAL knowledge of TCP/IP packet structure,
ethernet, internet, etc. or is a good working knowledge of IBM and
internet USAGE sufficient?
You need to know a bit about IP routing.
--
--russ <nelson@clutx.clarkson.edu> I'm proud to be a humble Quaker.
It's better to get mugged than to live a life of fear -- Freeman Dyson
I joined the League for Programming Freedom, and I hope you'll join too.steve@johnson.jvnc.net ("Steven L. Johnson") (03/27/91)
>1) Is there any truth to what I've heard? Can I run TCP/IP over a >modem? Yes, two ways. First, and most common, is SLIP (Serial Line Internet Protocol). Second, is PPP, the newer Point to Point Protocol. I currently run dial-up SLIP access from a Compaq 286 box to the Internet (NSFnet backbone node at Princeton). >2) Aside from speed, what differences will I notice between this >implementation and an "ethernet-ed" IBM running "TELBIN / TN3270" and >"FTP"? Well, theory says that SLIP is a full IP access. But in actual practice many of the IBM-PC programs won't run because they make assumptions that all IP datagrams will have a 14 byte ethernet header tacked onto the front, or that the ARP protocol is available. It is my understanding (although no experience) that some versions of TELBIN and TN3270 do support the Packet Driver type 6 packets (i.e. SLIP). I don't believe that the commercial packages (from FTP, Sun, B&W, etc) suffer from these problems. This 'compatibility problem' would go away if someone wrote a packet driver that accepted etherenet frames (PD type 1) from the user and converted them to SLIP frames for network transport, and hacked fake ethernet id and ARP service. I've had limited discussions with people to implement this functionality, but have seen little interest. I included this discussion, because I'm sure someone will tell you that you can just use the SLIP packet driver and everything will work. It doesn't, unless the program specifically has slip packet driver support. >3) What software do I need and what's the installation process like? I've used Phil Karn's KA9Q package successfully. It is free for Ham Radio people and universities; a license is needed for other use. Full source is available, a big plus. Telnet support is very weak; it works but no terminal emulations. If you find versions of telbin, ftpbin, tn3270 that support slip packet formats, you can get the slip driver itself from sun.soe.clarkson.edu. Alternatively of course there are the commercial packages. The installation varies from package to package, and many people have reported frustration with all of the packages. The error messages are not necessarily intuitive. >4) Do I need the cooperation of a current internet machine for me to >access the internet and, if so, what does that machine need to provide >me with? You need the cooperation of a machine. Many people run SLIP on a unix box connected to the Intenet. I haven't done this. I have connected directly to a Cisco router and a Cisco terminal server which directly supported SLIP access. These of course had to be configured to route packets for my IP address (also security config'ed also). Since I purchased this service, the Internet side was all done for me (thank goodness). I imagine that the procedure varies highly dependent on the type of service (single IP address or network gateway), and what type of machine you're tying into on the Internet side. >5) Do I need any TECHNICAL knowledge of TCP/IP packet structure, >ethernet, internet, etc. or is a good working knowledge of IBM and >internet USAGE sufficient? To install and use SLIP on the PC side, I wouldn't think so. But to resolve problems, someone will. It depends on if there is any SLIP experience on the machine you connect to, and how willing they are to tackle PC problems. >6) Do I really want to do this???? (Don't bother answering this one - >the questions above are what I really need!) In my case, I both wanted to and did. It provides me with a flexible and cost effective access to the Internet. -Steve
ITMS400@INDYCMS.BITNET (Manjit Trehan) (03/27/91)
> . . . >They need to set up a router that can use SLIP (or PPP). The cheapest >way to do this is using Phil Karn's (KA9Q) NOS. The only hitch with it >is that only educational or amateur radio users can use it. > . . . > Does this mean, a PS/s with connections to a modem and ethernet could act as a router using Phil Karn's (KA9Q) NOS (supporting SLIP), so I could call the PS/2 from home and use FTP and TELNET and not have to purchase any other equipment to accomplish this task? Thank you. Manjit
nelson@sun.soe.clarkson.edu (Russ Nelson) (03/28/91)
In article <9103270832.aa15221@louie.udel.edu> ITMS400@INDYCMS.BITNET (Manjit Trehan) writes: > . . . >They need to set up a router that can use SLIP (or PPP). The cheapest >way to do this is using Phil Karn's (KA9Q) NOS. The only hitch with it >is that only educational or amateur radio users can use it. > . . . Does this mean, a PS/s with connections to a modem and ethernet could act as a router using Phil Karn's (KA9Q) NOS (supporting SLIP), so I could call the PS/2 from home and use FTP and TELNET and not have to purchase any other equipment to accomplish this task? Yes, exactly. I've done it. The only tricky thing is to get your network's routers to route to your remote PC. That can usually be done by using the ARP hack (set up a hard-coded ARP entry that points the local Ethernet to your PC at home). -- --russ <nelson@clutx.clarkson.edu> I'm proud to be a humble Quaker. It's better to get mugged than to live a life of fear -- Freeman Dyson I joined the League for Programming Freedom, and I hope you'll join too.
dzoey@TERMINUS.UMD.EDU (03/29/91)
> From: Alan Gallatin <beguine!Alan.Gallatin@mcnc.org> > 1) Is there any truth to what I've heard? Can I run TCP/IP over a > modem? There are two "official" ways of running IP over a modem. The older, more widely implemented method is to use SLIP (serial line IP). I believe there is a SLIP packet driver, and all the commercial implementations support SLIP. SLIP has some administrative shortcommings, such as assignment of IP addresses and authentication. If you're the only one dialing into a slip server (many (most?) unix boxes can be configured as slip servers) the addressing problem is less important. The other way of running IP over serial lines is to use PPP (Point to Point Protocol). This solves the shortcomings of slip, but since it's a new protocol, isn't as widely implemented. I don't know if there's a PD PPP packet driver. > 2) Aside from speed, what differences will I notice between this > implementation and an "ethernet-ed" IBM running "TELBIN / TN3270" and > "FTP"? There are different administrative issues involving address generation and security. Once you've set up the SLIP connection, you shouldn't notice any difference though. In fact, you probably won't notice a lot of difference in telnet at all. > 4) Do I need the cooperation of a current internet machine for me to > access the internet and, if so, what does that machine need to provide > me with? Yes. You need a machine to talk to that runs the protocol you're running (SLIP or PPP). There are PD implementation of SLIP for various OS's and there are some PD implementations of PPP for some flavors of unix. Many TCP/IP vendors will be offering PPP products shortly if they don't already, and most, if not all currently offer SLIP service. > 5) Do I need any TECHNICAL knowledge of TCP/IP packet structure, > ethernet, internet, etc. or is a good working knowledge of IBM and > internet USAGE sufficient? You may need to know how to assign an IP address to your slip implementation. > 6) Do I really want to do this???? (Don't bother answering this one - > the questions above are what I really need!) It's really not that bad. There are a couple of magic numbers you need to know that vary between installations, but once you've done it once it's trivial. I wouldn't try SLIP using anything under 9600 baud. PPP has some compression options (I think, not sure) that make 2400 painful, but usable. Good luck, Joe Herman dzoey@terminus.umd.edu
dzoey@TERMINUS.UMD.EDU (03/29/91)
> From: Manjit Trehan <ITMS400%INDYCMS.BITNET@uicvm.uic.edu> > Does this mean, a PS/s with connections to a modem and ethernet could > act as a router using Phil Karn's (KA9Q) NOS (supporting SLIP), so I > could call the PS/2 from home and use FTP and TELNET and not have to > purchase any other equipment to accomplish this task? Absolutely. I know of several sites that use this setup or a simllar one using one of the commercial packages. This setup fails when you try and add more than two or three serial lines to the router. A couple of years ago, we took an old IBM AT (6 MHz) and set it up as a router for 2 ethernet cards, two token ring cards and two serial lines. It routed between the LAN cards well enough, but two active 9600 lines caused it to start missing interrupts. Today's machines may be able to handle the load though. There's a big difference between 25 and 6 MHz. So, yes, it's a nice, cheap solution. You start up the router when you leave the office and telnet in from home. Joe Herman U. of Maryland, DOSIP project dzoey@terminus.umd.edu
trier@cwlim.INS.CWRU.Edu (Stephen C. Trier) (03/29/91)
I've used the SLIP packet driver, but I'm curious about other solutions to the problem of network extension over serial lines. Has anyone worked on implementing PPP under MS-DOS? Any tips? Also, does anyone have any ideas on sharing a serial line between IP and Novell NetWare's IPX protocols? I have two ideas on this: (1) use PPP; (2) Encapsulate IP in IPX. The first has the disadvantage of being non-standard, at least for now, and the second would require a NetWare 3.11 router and two packets sent over the Ethernet for every one sent to or received from the remote site. (The modems used must be attached to a terminal server on the Ethernet.) A third possibility would be to encapsulate the IPX in IP and to let a NetWare 3.11 router deencapsulate. This seems to have all of the disadvantages of 2, with the additional disadvantage that custom IPX- in-IP encapsulation for DOS would have to be developed. Any comments or brilliant ideas? :-) -- Stephen Trier Case Western Reserve University Work: trier@cwlim.ins.cwru.edu Information Network Services Home: sct@seldon.clv.oh.us %% Any opinions above are my own. %%
jst@cca.ucsf.edu (Joe Stong) (04/04/91)
In article <NELSON.91Mar26201547@sun.clarkson.edu> nelson@clutx.clarkson.edu (aka NELSON@CLUTX.BITNET) writes: > The cheapest >way to do this is using Phil Karn's (KA9Q) NOS. The only hitch with it >is that only educational or amateur radio users can use it. Correction: Commercial use is possible, for a very modest fee, upon my last investigation. Contact Mr. Karn as karn@ka9q.bellcore.com for details. Joe Stong jst@cca.ucsf.edu