mcb@presto.ig.com (Michael C. Berch) (11/03/90)
In the referenced article, dhesi%cirrusl@oliveb.ATC.olivetti.com (Rahul Dhesi) writes: > While we're on the subject, the whole idea of requiring some sort of > leased line for Internet access is all wrong. In this age of > Trailblazers, low-volume access to a network shouldn't need to cost > more than $30/hour after hours plus $1.50 per month for maintaining the > account. Uhhh, $30/hour? That's about $21,000 per month, isn't it? Even assuming you typo'd "$30" for "$3" that would be $2,100/month which is still pretty high. Unless you meant some sort of access that would only be a few hours per day, which misses the main advantage of Internet access in the first place, which is real-time access to a large set of distributed resources. As an Internet user I can sit at my workstation during business hours and log in to remote accounts, FTP files to and from arbitrary locations all over the world, and send and receive mail that arrives in seconds or minutes. Dial-up SLIP or PPP on an after-hours batched basis can't offer those services and do not, to my mind, provide much of an advantage over dial-up UUCP. "Real" Internet access, to me, means real-time access. -- Michael C. Berch mcb@presto.ig.com / uunet!presto.ig.com!mcb / ames!bionet!mcb
pcg@cs.aber.ac.uk (Piercarlo Grandi) (11/05/90)
On 3 Nov 90 07:27:22 GMT, mcb@presto.ig.com (Michael C. Berch) said: [ ... on cheaper Internet access ... ] mcb> Unless you meant some sort of access that would only be a few hours mcb> per day, which misses the main advantage of Internet access in the mcb> first place, which is real-time access to a large set of mcb> distributed resources. As an Internet user I can sit at my mcb> workstation during business hours and log in to remote accounts, mcb> FTP files to and from arbitrary locations all over the world, and mcb> send and receive mail that arrives in seconds or minutes. All these goodies COST MONEY. If you are the one signing the cheques and you are given an option between instant service during business hours at 3X and evenings at X, maybe you think more than three times about the choice. mcb> Dial-up SLIP or PPP on an after-hours batched basis can't offer those mcb> services and do not, to my mind, provide much of an advantage over mcb> dial-up UUCP. "Real" Internet access, to me, means real-time access. Note that dialup IP connections are indeed non batched -- it is applications that would be batched, waiting for the IP connection to be established. Just like sendmail does today wih SMTP. The difference between dialup IP and dialup UUCP is that UUCP can only be offline, while IP can also be online. The difference between dialup IP and direct link IP is that dialup IP does not give continuous access, but only on request. It is up to you do delay the request or not. So the issue is not batched vs. online, but continuous vs. on demand. Once we all have ISDN and IP over ISDN we will all have continuous IP at the same price as dialup IP; for now, dedicated lines offering continuous Internet connectivity are expensive... -- Piercarlo "Peter" Grandi | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk Dept of CS, UCW Aberystwyth | UUCP: ...!mcsun!ukc!aber-cs!pcg Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk
jcurran@SH.CS.NET (11/06/90)
Dialup IP services are quite inexpensive, and if set up with care will give all the advantages of a dedicated circuit only with an occasional 30 second delay (those times when the line must be brought up.) Yes, dedicated circuits are very nice. But if it takes a dial-up line to get some companies on the Internet, then so be it. /John
peter@ficc.ferranti.com (Peter da Silva) (11/10/90)
In article <9011061147.AA20765@ucbvax.Berkeley.EDU> jcurran@SH.CS.NET writes: > Dialup IP services are quite inexpensive, and if set up with care will > give all the advantages of a dedicated circuit only with an occasional > 30 second delay (those times when the line must be brought up.) Um, won't this cause problems with SMTP? What does SMTP do when the destination is only available for brief periods, or should you handle your mail via an MX? -- Peter da Silva. `-_-' +1 713 274 5180. 'U` peter@ferranti.com
jdeitch@jadpc.cts.com (Jim Deitch) (11/10/90)
In article <WA_6L.@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes: >In article <9011061147.AA20765@ucbvax.Berkeley.EDU> jcurran@SH.CS.NET writes: >> Dialup IP services are quite inexpensive, and if set up with care will >> give all the advantages of a dedicated circuit only with an occasional >> 30 second delay (those times when the line must be brought up.) > >Um, won't this cause problems with SMTP? What does SMTP do when the >destination is only available for brief periods, or should you handle >your mail via an MX? >-- >Peter da Silva. `-_-' >+1 713 274 5180. 'U` >peter@ferranti.com Not at all. SMTP will just hold the message on queue until either sendmail or whatever you are using to smtp with wakes up and tries again to send it. If it can't connect within about 3 days or so then it is returned to the sender. This is the way it works for both directions. Once you have the link up you can invoke sendmail -q to run the queue and deliver what it can. Jim -- UUCP: nosc!jadpc!jdeitch ARPA: jadpc!jdeitch@nosc.mil INET: jdeitch@jadpc.cts.com
jcurran@SH.CS.NET (11/11/90)
Regarding dialup IP services, Peter da Silva writes: > Um, won't this cause problems with SMTP? What does SMTP do when the > destination is only available for brief periods, or should you handle > your mail via an MX? As long your implementation automatically brings up the circuit when there is a packet queued (at either end), the application layer can not distinguish dialup IP services from dedicated. SMTP simply gets a long delay on the initial connection. /John
bzs@world.std.com (Barry Shein) (11/11/90)
>As long your implementation automatically brings up the circuit when there >is a packet queued (at either end), the application layer can not distinguish >dialup IP services from dedicated. SMTP simply gets a long delay on the >initial connection. That doesn't quite answer Peter's message. What about some random host out there with mail for you? He tries to connect, gets a timeout since you're not dialed in at the moment, and re-queues. Chances are slim that you'll be dialed in when he happens to retry unless you're dialed in a lot. Of course, if the other host will also dial you then that's a solution. But I'm pretty sure (due to voice network charges and the service relationship usually implied) this is not the model most people are thinking of, they are effectively a leaf node and dial a centralized host providing the SLIP service to them. One has to either use MX records so the centralized host accepts and forwards the mail (the easiest solution), or use something like POP. -- -Barry Shein Software Tool & Die | {xylogics,uunet}!world!bzs | bzs@world.std.com Purveyors to the Trade | Voice: 617-739-0202 | Login: 617-739-WRLD
imp@marvin.Solbourne.COM (Warner Losh) (11/11/90)
Someone write: >>As long your implementation automatically brings up the circuit when there >>is a packet queued (at either end), the application layer can not distinguish >>dialup IP services from dedicated. SMTP simply gets a long delay on the >>initial connection. But most systems time out if they don't get a connection after 30 seconds or so. When I dial in to work from home, it takes at least that long to make the connection. Since a mailer will requeue to try later (anywhere from 10 minutes to a day depending on the mailer%), the line may well have disconnected by then to save charges. In article <BZS.90Nov10150636@world.std.com> bzs@world.std.com (Barry Shein) writes: >Of course, if the other host will also dial you then that's a >solution. But I'm pretty sure (due to voice network charges and the >service relationship usually implied) this is not the model most >people are thinking of, they are effectively a leaf node and dial a >centralized host providing the SLIP service to them. However, SMTP doesn't work this way in practice. Sure, there is a command that tells the mail daemon on a remote machine to send mail down the line, but it isn't widely implemented. Unless my machine can connect to your machine, the mail usually doesn't go out. >One has to either use MX records so the centralized host accepts and >forwards the mail (the easiest solution), or use something like POP. This sounds like a good idea. But if you are going to do dialup already, why not just use uucp mail? It is simpler to setup than arranging slip lines. The whole idea of dialup access is good, if it can be done "fast" and on demand. TCP connection would show the line is still in use, but how do you work out things like UDP packets? There is no "connection" data or state associated with them. Warner -- %Mailers -- Sendmail is one mailer that is on the Internet. There are others that don't behave the same way that sendmail does, but are not the less just as standard conforming as sendmail. -- Warner Losh imp@Solbourne.COM How does someone declare moral bankruptcy?
jcurran@SH.CS.NET (11/12/90)
> This sounds like a good idea. But if you are going to do dialup > already, why not just use uucp mail? It is simpler to setup than > arranging slip lines. > > The whole idea of dialup access is good, if it can be done "fast" and > on demand. TCP connection would show the line is still in use, but > how do you work out things like UDP packets? There is no "connection" > data or state associated with them. > > Warner Dialup IP provides a general transport service for mail, ftp, telnet, etc. Many people are using dialup IP with automatic initiation for this reason and it works quite well. Certainly a little care has to be used when setting up mail and DNS [kids, don't try this at home..], but it's worth it for those sites who can't afford the cost of a dedicated circuit. This line of conversation started regarding the high cost of connecting to the Internet; it's important to show there are alternatives to the direct line. /John
dave@ecrc.de (Dave Morton) (11/13/90)
In article <9011101731.AA20352@ucbvax.Berkeley.EDU>, jcurran@SH.CS.NET writes: |>Regarding dialup IP services, Peter da Silva writes: |>> Um, won't this cause problems with SMTP? What does SMTP do when the |>> destination is only available for brief periods, or should you handle |>> your mail via an MX? |> |>As long your implementation automatically brings up the circuit when there |>is a packet queued (at either end), the application layer can not distinguish |>dialup IP services from dedicated. SMTP simply gets a long delay on the |>initial connection. |> |>/John This is exactly how tund appears to work on X.25 links. If you're on a fixed cost X.25 net like the WiN then that's ok, if you're on a fee per packet X.25 net then you might end up paying even though the other site has established the call. Tund, for example, re-establishes it from your side. We ran into this situation recently - it can be expensive.... Dave Morton, European Computer Research Centre Tel. + (49) 89-92699-139 Arabellastr 17, 8000 Munich 81. Germany. Fax. + (49) 89-92699-170 E-mail: dave@ecrc.de