TOASTERNETS An introduction on building your own. By Tim Pozar 1. - DEFINITION OF TOASTERNET... Recently with the development of low cost software and hardware that supports the Internet networking protocols and the commercialization of the Internet, a level of access for users and new concept in coopretive networking has been born. "Toasternet" is the generic term for Internet-connected computer networks built very cheaply so as to have a cost that a small busness, school or individual can afford. In fact, it has been joking said that these networks are so cheap, you can connect everything in sight, including your toaster. Generally speaking, most Toasternets exist to meet a group's or individual's communications needs, rather than profit as a motive. At the same time Toasternets are poping up everywhere with low cost access to the Internet, there is a push to develop programs to provide better naviation tools for the Internet to aid in search and retrival of information. The most notible tools/programmes are Gopher, WAIS, and World Wide Web. 2. - WHAT'S BEHIND THE MIRRORS... The Internet has typically used expensive technology to transport its packets. Lease lines, microwaves, and fiber are tradionally costly and require a technical knowlege that most folks don't have. These "costs" are translated into high access fees to connect to the Internet. Recently, with the development of personal computers and networking hardware and software, the cost and expertise to install local and wide are networks has dropped dramaticly. Some of the advances are: May 21, 1993 1 * Dial-up telephone modems using standards like V.32bis or V.FAST and compression standards like V.42bis to create links over low-cost, residential lines have just become fast enough to run networking protocols like the Internet Protocol (IP). * Packet routers can be built out of inexpensive personal computers running public-domain or shareware software like KA9Q, PCROUTE, or 386BSD can send IP over these fast modems from the Internet to computers running client software for the users. The hardware and software advances are only half of the story. A non-profit, or cooprative "agreement" is made between the members of a Toasternet. The agreement can also includes the nonexclusive use of the network where, members can also resell their connections, and the agreement may also include the non-restriction of data unless existing law may prohibit it. With the use of these tools, the availiblity of a close access point to the Internet (aka. Point Of Presents - POP), and the cooprative nature of toasternets, the Internet can be accessed at a very low cost to the user. 3. - HOW INTERNETWORKING IS DONE... A Toasternet looks just like any other Wide Area Network (WAN), where leased lines, and/or radio links are used to connect hubs to other links that eventually connect to each machine or host in the network. Since a Toasternet is not an isolated network there needs to be at least one link to the outside world. This link is a connection to an Internet provider at the most convenient POP to the network. We will start looking at the Toasternet layout from the IP provider's POP going towards the hosts. This is more of a technical tour through the net and we will cover more of the politics and social aspects of the Toasternet later. 3.1 - The POP The POP would normally be a commercial provider. The provider would require a monthy fee and a startup fee to install. The startup fee may include the purchase of a 2 May 21, 1993 commercial router ($4,000 to $20,000). The montly fee would vary with the bandwith that the Toasternet requires. Monthy fees are typically less than $1000 a month for 56 Kilobit per second (Kb/s), and upwards to $2000 a month for T1 or 1.544 Megabits per second service. 3.2 - Routers and Links From the POP the Toasternet starts it's distribution. A number of technlogies may be mixed and matched to create data paths to deliver IP to the user. 3.2.1 - The Links 3.2.1.1 - Lease lines (i.e., T1 and 56Kb/s) There are several leased line options offered by your local phone company. The lines you would be most likely use for high speed data links are [FIXME: right nomanclature?] 56K, T1. 56K linkes will support (as you would imagine) 56 Kilobits per second and T1 will supply 1.544 Megabits per second. 56K and T1 are used for long distance runs where you need to get data to the next Central Office (CO) area, LATA, state or country. It should be mentioned that there is another high speed link that most phone companies will offer. It is called T3 and will provide data at 45 Megabits per second. Normally these links are pretty expensive, and until a Toasternet gets several thousand hosts on it's net, T3 would not be accessable to a Toasternet's pocketbook. [FIXME: How about fiber?] Cost of lease lines vary with distance and speed of the link. Normally the local telephone company will charge for the distance of the link and for each end termination. An example breakdown for cost of a 30 mile 56Kb/s link would be: (FIXME: get real prices) May 21, 1993 3 Installation ....................... $1000* Termination ($100 per end) .......... $200* Milage ($1/mile after 10 miles) ..... $ 20* In contrast, a T1 link would run: (FIXME: get real prices) Installation ....................... $1000* Termination ($100 per end) .......... $200* Milage ($2/mile after 10 miles) ..... $ 40* [*Pacific Bell 5/1/93 for the SF LATA] These prices may be higher or lower in your area as the local phone companies' rates vary wildly. Lease lines are a bit more involved and more expensive to order than your average residential line. A bit of planning is involved. For instance, where you install a leased line needs to be considered at some lenght. You want to design the link to be the most effective for the speed needed and the area you need to serve. You also want the link's ends to be placed at locations were they can stay for some period of time since each move will cost you another installation fee. Please see [FIXME: What is the real ref?] 3.2.1.5 for considerations in choosing the what kind of link you need. Additional hardware is required for lease lines. Each end of the leased line is terminated with the equivalent of a modem. These boxes are called Customer Service Units/Data Service Units, or CSU/DSUs. Prices for CSU/DSUs will start around $550 and go up to about [FIXME: get prices from Dowty] $750. On the CSU/DSU you will have at least three connections, power, lease line connection and interface connection. Power should be simple enough where you just plug it into the closest power outlet (See [FIXME ref?] 3.x for bullet proofing your network). The lease line connection will be tied to the lease line, and the interface will go to the router. CSU/DSUs can be ordered with a number of different interfaces. The most common is V.35. V.35 defines the [FIXME: Hardware and electrical? Does it include RS-422 too?] [FIXME: What's happening with RS-232C as an Interface?] [FIXME: What's happening with async vs. sync as an Interface?] 4 May 21, 1993 3.2.1.2 - Dial-up phone lines. (i.e., POTS, ISDN, Switched 56) Unlike lease lines, dial up lines can be temporary links. The data path needs to be "built", when needed, by dialing the number of the other end of the link. 3.2.1.2.1 - POTS "Plain Old Telephone Service/System" or POTS lines are the voice lines that we commonly used to dial up our relitives, work, etc. As most of the readers to this essay would already know, with the addition of a device called a modem, this POTS line can be used to transfer data over it. At this point in time, maximum speeds of a POTS circuit is 14.4Kb/s for the V.32bis standard protocol, and 28.8Kb/s for V.FAST. Addionally, the compression standard V.42bis for modems can increase the througput up to four times. It is claimed that with a V.FAST modem using V.42bis can have a potential thoughput of 115.2Kb/s. This, by the way, is as fast as the serial port of a PC using a 16550 UART will do. There are a number of advantages to POTS lines. The best, pertaining to your telephone provider, is that they know how to order it and install hundreds of them a day. This solves most of the hassles with installation. In my area, Pacific Bell can take weeks to engineer and 3.2.1.2.2 - Switched 56 and ISDN These tarrifs are digital dial up phone lines. The POTS circuit described above is an analog phone line. With POTS circuits you are transmitting different tones that represent the digital signalling or the data that is traveling from one end of the line to to other. Digital circuits vary the voltage from one level to another that represent digial signaling. You do not need a "modem" that converts the data into tones, but you will need a device much like the leased lines' CSU/DSU that will "condition" the data for the digital circuit. They will also handling the signalling needed to "dial" the other phone you need to connect to. These devices are called [...FIXME]. Switched 56 has a data throughput of 56Kb/s and ISDN is May 21, 1993 5 64Kb/s or 128Kb/s depending on if one or both "B" channels are used. Tariffs for the above will be in the range of $10 to $50 a month, and could include a per minute charge of around $0.01 a minute. There is some effort by state Public Utility Commissions and concerned individuals to see that phone companies offer unmeasured residental rates. 3.2.1.3 - Radio links (i.e., AX.25 via KA9Q or PPP over high-speed microwave) Radio's main benifit is that the monthy cost can be significantly less than leased lines. Unfortunatly, high speed radio links can be costly to install. A T1 link could run as high as $30,000 for the link. There is some work by Amateur radio operators, and advances in spread spectrum radio that promise very low cost links that could move data as fast as T1 (1.544Mb/s) and T3 (45Mb/s) speeds. There are two paradymes for radio, point to point or point to multipoint. Point to point connections are more like SLIP or PPP connection where all of the traffic between two or more networks are going through a radio link and are terminated by a single router at each end. Normally point to point connections are used for high-speed backbones that carry the traffic to each POP. Point to multipoint links are more like ethernet or tokenet hardware where all hosts are trying to share the same resource. In this case, a single frequency or band of frequencies are used to talk to two or more hosts. These links are used for hubbing out connections and are more applicible to POPs feeding the last mile connections to hosts. When two or more radio transmitter want to "talk" at the same time there Licensing concerns... Satilite links... Concerns about the 230mS delay per hop. 6 May 21, 1993 3.2.1.4 - Special Phone Company Supplied Tariffs 3.2.1.4.1 - LADD Circuts A LADD (FIXME: Local Access D..) is a plain old pair of copper wires going from a customer's premises (prem) through a Central Office (CO) back to another customer's prem. This type of circuit does not have any amplifiers or equalizers built in and, in phone terms, it is called a "Dry Pair". Two strong points for LADD circuits are the low cost, ussually $8/month, and the ability with low cost line drivers to send data up to 115Kb/s. 3.2.1.4.2 - OPX 3.2.1.5 - Considerations on choosing the right link. Chossing the right link involves anserwing a number of questions about how the link will be used. * Is this a temporary link? * Can the link go up and down as demand warrants? * If it is a temporary link, can the user(s) of the link be happy with the speed of a dialup SLIP or PPP link? With V.32bis/V.42bis modems, the speed would be around 21Kb/s. ISDN links would be 64Kb/s or 128Kb/s depending on how many B channels used. * Are both ends of the link within line-of-sight of each other? Can one site see the roof of the other site? * Is the end of the link feeding many high demand users? May 21, 1993 7 3.2.2 - Routers At each branch of the links, routers are used to route the data down the proper path. Typical routers are: * Commercial (CISCO, 3com, Livingston) * Shareware/Public Domain (KA9Q, PCROUTE, 386BSD) 4. - CASE STUDIES... 4.1 - TLG (ONE PARAGRAPH) topology (20 words) constituency (WE'RE SO SOCIALLY RESPONSIBLE WE CANT STAND IT) history how it started 4.2 - RAINnet (TWO PARAGRAPHS) topology (20 words) constituency (WERE SO RIGHTEOUS WE CANT STAND IT EITHER) Randy brags here (yes Randy) history how it started IP suppliers: how they came to exist our troubles with (in context) -- CONCLUSION What we are doing now. (ONE PARAGRAPH) Where we're headed. With the combination of the development of Toasternets and better navigation tools the Internet .... 8 May 21, 1993 CONTENTS 1. - DEFINITION OF TOASTERNET........................... 1 2. - WHAT'S BEHIND THE MIRRORS.......................... 1 3. - HOW INTERNETWORKING IS DONE........................ 2 3.1 - The POP....................................... 2 3.2 - Routers and Links............................. 3 3.2.1 - The Links 3 3.2.1.1 - Lease lines (i.e., T1 and 56Kb/s) 3 3.2.1.2 - Dial-up phone lines. (i.e., POTS, ISDN, Switched 56) 5 3.2.1.3 - Radio links (i.e., AX.25 via KA9Q or PPP over high-speed microwave) 6 3.2.1.4 - Special Phone Company Supplied Tariffs 7 3.2.1.5 - Considerations on choosing the right link. 7 3.2.2 - Routers 8 4. - CASE STUDIES....................................... 8 4.1 - TLG........................................... 8 4.2 - RAINnet....................................... 8 - i -