Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!mstar!mstar.morningstar.com!bob From: bob@MorningStar.Com (Bob Sutterfield) Newsgroups: comp.mail.misc Subject: Re: mail servers Summary: soapbox, crying in the wilderness Message-ID: Date: 22 Aug 90 14:26:25 GMT References: <1990Aug17.021921.1863@chinet.chi.il.us> <1594@i2ack.sublink.org> Sender: usenet@MorningStar.COM (USENET Administrator) Reply-To: bob@MorningStar.Com (Bob Sutterfield) Organization: Morning Star Technologies Lines: 68 In-Reply-To: venta@i2ack.sublink.org's message of 19 Aug 90 17:55:44 GMT A mail-based archive server is an impolite and destructive way to distribute large amounts of information, and should be discouraged in such applications. When a mail-based archive server (MBAS) sends a requested chunk of stuff (CoS) to the requestor, it has no way to know what transport mechanisms will be used along the route. If the transport mechanisms are all on zero-incremental-cost-per-use networks, all is well. Very often, at least some of the trip will be along edges in a graph of an intermittent-connection, store-and-forward network, usually involving a nonzero incremental cost for transporting each CoS. Most such edges are maintained, and paid for, by the nodes on either end. They voluntarily allow other traffic to pass over their link, usually with the understanding that the volume will be small enough to be of negligible cost. However, if someone starts shipping megabytes of archives across those links, the distribution cost is borne by someone other than the requestor. This is impolite. Eventually, such hospitality abuse can cause the eventual removal of that connection from general "public service", and the two nodes will return to maintaining a private edge for their own use. Traffic will then shift to other edges, increasing their burden and encouraging them to retreat similarly. In the extreme case, the practice of general use and hospitable availability of connections will disappear. Everyone would need to maintain distinct links with every other site with which they wish to exchange traffic. Free, open, cooperative communication as we know it would wither, a nostalgic remnant of a bygone era. But take heart, there's another way! Instead, sites can pay for the connectivity they use for shipping large CoSs. If they're connected to a zero-incremental-cost-per-use network then they pay for the connectivity every month in their leased line bills. This is the case on the IP Internet, the BITnet, SPAN, and others. If a site is not so connected, then they can pay for the transient connectivity when they need it. For example, the Computer Science department at the Ohio State University has for several years maintained just such an archive. Similarly, UUNET Communications Services offers dialup UUCP file transfer service even to sites without pre-established UUNET accounts, through their "900 number" facilities. The connectivity appears in the requestor's next telephone bill because, unlike OSU CIS, UUNET must recover the costs of providing the service. Such archives' contents are freely available to anyone who wants them and is willing to pay the cost to acquire them. No provision is made to assist requestors in freeloading on other sites' generous hospitality, other than in exchanging relatively small mail messages containing instructions and assistance in using the archive. Any number of schemes are possible, usually based around a reliable file transfer protocol. Pay-per-use archives run today using Kermit, UUCP and Fido request protocols, and probably innumerable others. Note that in saying "pay-per-use" I mean paying for connectivity (usually the phone company), not paying for the privilege of access nor for the archive contents themselves. The work involved in maintaining such access to an archive is negligible, compared to the work of maintaining the archive itself. In fact, compared to the work of untangling bounced mail replies from a MBAS, it should be quite attractive to the archivist. Once set up, the access mechanism pretty much runs itself. But MBASs are so popular, and so useful to so many people, I often feel like a voice crying out in the wilderness. Please, at least provide and encourage other, more polite distribution means. I wouldn't want such a good thing as people's desire to share to be a contributing cause to the dismantling of open networks!