For all new, and old users of packet, A Maryland PBBS sysop by the name of Pete, KA3RFE, put together this quite straightforward and easy-to-read guide. It's recommended reading for all. What motivated Pete to do it? Well, one major reason was all the TNC's with "PK-232" in their callsign field after the X-mas holidays, usually loading down the Northern Virginia LAN on 145.07. Pete determined that the "PK" prefix used to belong to the Dutch West Indies. We wrote to the ARRL to determine if we could get DXCC credit. So far, no response :-). However, the last straw was seeing the following beacon: JOE HAM IS NOT IN, MAKE NO ATTEMPT TO CONNECT TO HIS STATION (Well, the last one didn't really happen, but it's still funny). Please keep the following in mind: 1. Pete, KA3RFE, is the author and is solely responsible for its content. 2. All questions, comments, and criticisms should be sent to Pete via AMPR KA3RFE@KA3RFE.MD.USA. 3. Pete doesn't mind if you disseminate it, just make sure that it's not for commercial gain and that Pete is ALWAYS given proper attribution. 4. Requests for garbled, lost, or expired-on-your-news-server issues should be sent to me. 73, Paul W. Schleck, KD3FU ACMNEWS@zeus.unomaha.edu uunet!unocss!zeus!acmnews 137.48.1.1 ps67@umail.umd.edu uunet!mimsy!umail!ps67 128.8.10.28 ***************************************************************** MSG # TR SIZE TO FROM @BBS DATE TITLE 4673 B# 3444 ALL KA3RFE MDCBBS 910106 ATT: New Packeteers Forwarding path: W3IWI N4QQ N2GTE KA3RFE This is for those of you got new tncs for Christmas and are just starting out in the Wonderful World of Packet. There are some things you should know that your tnc manual may not have mentioned. Some terms which get people confused: 1) Home BBS: A "home BBS" does not refer to the mailbox program which your tnc may have in it's guts. It refers to a full-service BBS which handles personal mail, bulletins, and file transfers. Your "home BBS" would be a full-service BBS which you might check into often to read bulletins and to pick up any personal mail which might be held for you. If you have arragned for a full-service BBS to forward your personal mail to your mailbox, your home BBS still remains that full-service BBS. This term is important as several BBS programs will ask you to enter a "home BBS" the first time you connect to it. 2) Node: You can figure a "node" to be something of a packet switchboard which has the ability to operate on several frequencies. A node differs from a digipeater in the sense that it handles all of the packet housekeeping chores within its program. Most nodes have more than one operating frequency and they can shuttle packets back and forth via any number of intermediate nodes. The benefit of using a node over a digipeater is that the node will find the quickest way to make the connection whereas a digipeater will only try to connect you to the station you tell it to connect to, regardless of whether the digipeater can hear it or not. You cannot send mail to a node. It is not a mailbox or a BBS. 3) Network BBS: A network BBS is a full-service BBS which is operating under a special node-compatible software program. Network BBSs will show up in node broadcasts and can be connected to over the node network by entering a connect request to the network BBS alias. Generally, a network BBS will have an alias in which either BBS or BB is part of the alias. For example: ANNBBS is the alias for KA3RFE BBS in Annapolis; BWIBBS is the alias for WB3V BBS in Severn. BBJ9X is the alias for AJ9X's tcp/ip BBS in Westminister. The network BBS alias is ONLY FOR CONNECTING. You should not use the network BBS alias as an entry for "home BBS" when your are asked to enter your home BBS. Use the callsign of the BBS and not its alias as your home BBS when asked to enter it. The same goes for sending mail to a netowrk BBS. If you enter a message to KA3RFE @ ANNBBS, the message will never get there since ANNBBS is only an alias for use in connecting to it over the node network. IF you enter a message to KA3RFE @ KA3RFE, the message will be forwarded without much hassle. I strongly suggest that you throurghly read your tnc manual and also suggest that you get a copy of "Your Gateway to Packet Radio" from somewhere. Its the best book yet written on the ins and outs of packet radio. 73, Pete, sysop KA3RFE (ANNBBS) Annapolis, Md. MSG # TR SIZE TO FROM @BBS DATE TITLE 4813 B# 1760 ALL KA3RFE MDCBBS 910110 Att New Packeteers pt.2 Forwarding path: W3IWI N4QQ KA3DXX WA7NTF KA3RFE This bulletin is being re-sent at the request of several people: "GARBAGE CHARACTERS" You may see some very strange-looking characters flitting across your moniter's screen from time-to-time. Those funny-looking things are symbols for binary data being transmitted. There are several sources which use binary data instead of text. Net/Rom nodes use binary data in their nodes broadcasts. The purpose of the node broadcasts are to inform other nodes within range what nodes they can connect to. The data is binary for reasons of accuracy. Another source of garbage characters is binary file transfers from a BBS to a user. These transfers are generally executable programs which the BBS might have stored for downloading by users. These differ from text files in that the binary code contains control characters and computer programming commands which cant be sent as text files. A third source of garbage characters is tcp/ip packets being sent between two stations using that protocol to exchange files or mail. Tcp/ip is a protocol which has several different layers to it and can be used to interface with some of the major computer networks such as those used by colleges and government computers. So, if you see funny-looking symbols on your monitor, dont panic, its just binary traffic going bye. 73, Pete KA3RFE @ KA3RFE BBS MSG # TR SIZE TO FROM @BBS DATE TITLE 4766 B# 3742 ALL KA3RFE MDCBBS 910108 ATT: New Packeteers pt 3 Forwarding path: W3IWI KA4USE N4QQ N2GTE KA3RFE SENDING MAIL/BULLETINS Most BBS programs use the same commands to send mail and bulletins. One of the most common mistakes in sending messages of any type is the confusion between what is mail, and what is a bulletin. The issue gets further confusing when trying to determine how to send a bulletin meant for all BBSs is a given bulletin distribution scheme. Generally, there are three commands for sending mail and bulletins: A) S.....Most BBS programs treat the S command as a command to send a PRIVATE message. For instance: entering S KA3RFE will send a private message to KA3RFE...but only on the BBS you enter the message on. If KA3RFE does not use the BBS you are entering the message on, the BBS program will try to forward the message to KA3RFE...but ONLY if that BBS has KA3RFE listed in its forwarding file. If you try to send a bulletin using S alone, the BBS will still treat that message as a private message. So, entering a bulletin using "S ALL @ MDCBBS $" will result in a private message to NOBODY at MDCBBS except for SYSOPS, because a private message to "ALL" could only be read by sysops or a ham who's callsign is "all". Since "all" is not a legal callsign, nobody else can read the message Did you notice the "$" in the example above? To send a bulletin out to other BBSs, the address has to include the $. This tells the BBS that the bulletin should be forwarded out to other BBSs. So, you must include that $ if you want the bulletin to be sent to other BBSs. B) SP......The SP command means "Send Private". This tells the BBS that the message you are sending is "eyes only" for the addresssee. The sysop will be able to read that message but no one else will be able to read it. This is the same command as the plain S command. To avoid confusion, you should always send your private messages to another ham using the SP. C) SB.....This command means "Send a Bulletin". There are two types of bulletins you might send. One type would be only for users of the same BBS you are entering the bulletin on. If you were connected to KA3RFE BBS and you sent a bulletin reading "SB ALL", the BBS will treat it like a local bulletin and it will only stay on KA#RFE. If you sent a bulletin titled "SB ALL @ MDCBBS" the bulletin will still be considered a local bulletin on KA3RFE. Why????? To send a bulletin which you want forwarded to "ALL @ MDCBBS" you have to tell the BBS you want it forwarded.....THATS WHAT THE "$" IS FOR. So, if you want your bulletin sent to every BBS which accpets the MDCBBS distribution scheme, you have to add that $. The correct way is "SB ALL @ MDCBBS $". So, to sum up....use S and SP for PRIVATE messages. ("Mail"), and SB for BULLETINS. Dont forget the "$" in the address if you want your bulletin to get forwarded. Try it out! Send me a private message to KA3RFE @ KA3RFE.md. If it gets here, I'll send you a reply. 73, Pete KA3RFE sysop KA3RFE BBS MSG # TR SIZE TO FROM @BBS DATE TITLE 4894 B# 1594 ALL KA3RFE USA 910113 Att: New Packeteers pt 4 Forwarding path: W3IWI W3ZH N4QQ N2GTE WB3V KA3RFE In Part 3 I stated that a dollar-sign symbol must be appended to any bulletin which you want to have forwarded out from the BBS you entered it on. I've gotten information that entering the dollar sign is not required on CBBS and RLI bbs systems for the forwarding-out to take place. At this point, to the best of my knowledge, the dollar sign is required on MBL, MSYS, and REBBS systems. There are other systems which may not require the dollar sign. Your best course of action is to ask your sysop if you need to append the dollar sign to your bulletins for them to be forwarded-out. Those of you who are sysops: I want to make this series helpful, so correct me if I dont have it correct! I dont know how BQE's system handles bulletins, nor FISBBS, and maybe I'm wrong with MSYS and AA4RE...(I ran both MSYS and AA4RE, but I've forgetton and dont have the docs any more...getting senile...) The dollar-sign IS required for the WA7MBL bbs and with another BBS system being beta-tested in Anne Arundel County MD called "GTEPMS". Part 5 will deal somewhat with tnc settings....look for it soon! 73, Pete KA3RFE @ KA3RFE.md.usa MSG # TR SIZE TO FROM @BBS DATE TITLE 4968 B# 3405 ALL KA3RFE MDCBBS 910114 Att: New Packeteers pt 5 Forwarding path: W3IWI WA3ZNW NB3P KA3RFE SETTINGS: Nothing generates more frustration than trying to set up a tnc to operate effectively when you dont understand the language. This is a short run- through of the more important parameters which enable your tnc to work properly with minimum hassle. FRACK: FRACK is short for FRame ACKnowledge. It is the timer which tells the tnc how long to wait for an acknowledge frame from the other station before re-sending a frame. Typically, tncs come with a default value of 4, which is adequate. However, if you are operating on a very busy channel, you may want to increase FRACK to 6, or even 8. A short FRACK value can lead to retrying-out, so dont set it below 4 or so. RETRY RETRY tells the tnc how many times to keep sending a packet that does not get ACK'ed by the other station. This usually defaults to 10 from the factory. After the 10th retry, the tnc "times out" and the connection is broken. A value of 10 is just fine. Some people say a shorter value is better but 10 will do. If you set your tnc retry value to 0, the tnc will NEVER time-out! This is NOT a good idea! DWAIT DWAIT enters a pause in-between transmitted packets to let digipeaters to transmit first. This is usuallly set by local agreement. Ask around to find out what your DWAIT should be. TXDELAY This determines how soon the packet will be transmitted after the tnc keys the radio. The purpose of TXDEAY is to insure that the first few parts of the packet dont get chopped off by a slow-keying transmitter. You will have to set this based on what sort of transmitter you are using. Good values range from around 30 to 50. Longer TXDELAY values just take up air time. You can figure that TXDELAY works the same way that you do on voice....you wait a second or so after keying the mic before you start talking....well, thats TXDELAY! There are more settings which control your tnc, but the above are the ones that make the difference. There are also two settings for your RADIO which are important: DEVIATION: W3IWI reccomends a deviation of no more than 3 percent for optimum packet operation. A too-wide deviation will reult in lots of retries and timing-outs. VOLUME: Your volume-control is the most important setting on your radio insofar as receiving packets is concerned. If you have the volume too loud, the tnc will not be able to decode the packets, and, of course, if the volume it soo low, the tnc wont hear the packets. The best method of setting your volume control is to open your squelch and increase your volume control until you see the DCD light on the tnc come on. That's your setting. 73, Pete KA3RFE @ KA3RFE MSG # TR SIZE TO FROM @BBS DATE TITLE 5029 B# 4630 ALL KA3RFE MDCBBS 910116 Att: New Packeteers Pt 6 Forwarding path: W3IWI KA4USE N4QQ WA3ZNW NB3P KA3RFE SETTINGS CONTINUED There are two more setting which you must consider when setting up your tnc. These settings have much to do with how well your RETRY rate is. PACLEN: PACLEN is short for PACket LENgth. It tells the tnc how many letters, numbers, and spaces should make up the length of the packet your tnc sends out. Most people use a PACLEN of 128 characters, which is ok under most circumstances, I suppose, but that depends highly upon how good the path is between stations, how crowded the channel is, and a couple other factors. On my BBS and node ports here, I use a PACLEN of 80 on my UHF port (when its operating....) as I dont have all that great of a path to the more distance stations, while my 2 meter port has a PACLEN of 180 and my 220 port runs a PACLEN of 120. The differences are due to channel loading, distance, and radio/antenna performance factors. BY THE WAY: PACLEN is NOT a substitute for inserting carriage returns in your transmitted signals. All PACLEN does is tell the tnc to transmit a packet after X number of characters have been inputted. If you make up a long message on a word processor and dont insert any carriage returns in the text, the message will scroll right off the screen of anyone trying to read the message! I am inserting carriage returns as I type this message. If I didn't, you wouldnt be able to read the bulletin! I put my carriage returns at the end of each line I type. When this bulletin gets forwarded out, the PACLEN setting will send X characters out, carriage return and all, and the finished product when you read it, will be exactly as I typed it. MAXFRAME: This is the last setting you need to worry about right now. MAXFRAME works with PACLEN to determine how much information your tnc will send out at any one time and will consult with RETRY to give you the bottom-line total thruput. (Thruput? ....all thruput means is how fast the job it getting done... when packets are just zipping along and being acked real fast, that's high thruput...) MAXFRAME means how many packets you want to have out un- acknowledged before more packets are sent. On a nice quiet channel where you are in within spittin distance of the station you are communicating with, MAXFRAME can be as high as 4 or 5. However, hardly anyone is on a nice quiet channel, so your MAXFRAME setting has to be set to reflect conditions. If the channel is real crowded and noisy, or if you time-out a lot with a high MAXFRAME, you might want to consider setting a MAXFRAME of only 1 or 2. On my UHF port, the channel is both busy and I have a poor- to-fair path to most of the stations I connect to. So, I set a MAXFRAME of 1. On my 2 meter and 220 ports, I set MAXFRAME to 2. I probably could get away with a setting of 4 on 2 meters and 220, but the channels are busy. A NOTE ON THE "$" IN SENDING BULLETINS I've heard from many sysops and two BBS software authors on the use of the dollar sign in sending bulletins which are to be forwarded out from the BBS you're entering it on. The info is being passed on here, somewhat modified to reflect the possibility that you may not know which sort of system you are using..... The WA7MBL BBS requires that you send bulletins to be forwarded out in this manner: SB ALL @(USA, etc) $ Other BBS systems dont require it, but if you are not sure which type of BBS you are using, you can enter the $ with no harm done. In fact, it may be a good idea to use the $ anyhow. It wont hurt, and wont make any difference if the BBS does not need it. (Thanks to all you sysops who sent me the info I needed to clear that up, and a special "thank you" to the two BBS software authors who were kind enough to respond.) MSG # TR SIZE TO FROM @BBS DATE TITLE 5026 B# 2411 ALL KA3RFE MDCBBS 910116 Att: New Packeteers, pt 7 Forwarding path: W3IWI KA3T WA3ZNW NB3P KA3RFE THE DIFFERENCE BETWEEN MAIL AND FILES When you log onto a full-service BBS, there are two separate things you can get into: Mail and Files. Some people get confused about what the two of them are. I know I did when I first got on packet. I thought a file was a file, whether it was a file or whether it was that long list of messages you get when you enter an "L" command. Well, as I found out, they aint the same animal. When a BBS refers to a "file", it's talking about a separate entry which is being stored apart from "mail". I guess I better define "mail" before I get into "files"....its easier. "Mail" means messages from one ham to another, or bulletins which the BBS has open. If ham A sends ham B a message, that's "mail". If a ham sends a message to be read by many people, that's called a "bulletin" but the BBS still calls it "mail". A "file" is not mail, nor is it a bulletin; although some bulletins might be converted to files by the sysop. A file is a permanent part of a BBS. The file might contain text, or it might be a binary file. (WHAT? I THOUGHT EVERYTHING IN PACKET WAS BINARY!) Not to worry...everything packet-ized is binary, but there is a difference in how the information is kept in the BBS. Binary files are those which are actually executable programs which can be downloaded from the BBS. These files require that you have a compatible binary file downloading program in order to get them from the BBS. Text files are those which are plain text and you can download them without needing any sort of special file downloading program. In most BBSs you can get into a text file area in which the documentation is kept with all the commands used by the BBS. So, MAIL is stuff from ham A to ham B, bulletins are from ham A to a selected audience, but still MAIL. FILES are the more permanent information on a BBS and come in two flavors: text and binary. Text files are sent in simple plain old English, while binary files look like the BBS has got the runs. 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA ********************************************************************* For those that thoroughly enjoyed the previous 7 chapters of the KA3RFE "Attn New Packeteers" Guide, here are the latest 3 installments. As you can see, they touch on many sore issues that have worked their way to the surface of the ham community in the wake of the "WA3QNS" citations by the FCC. Those that would enjoy the infamy of their callsigns being remembered with "the Titanic", "Adolf Hitler" and "Pontious Pilate" (not to mention the FCC's "Harden and Weaver Rule") are advised not to read these posts.... ;-) As always, they are written by a Maryland packet BBS sysop, Pete KA3RFE, and all comments or criticisms should be sent to him via: AMPR KA3RFE@KA3RFE.MD.USA Requests for lost installments due to Usenet barfs should, of course, be sent to me. 73, Paul W. Schleck, KD3FU ps67@umail.umd.edu ************************************************************************ MSG # TR SIZE TO FROM @BBS DATE TITLE 5733 B# 2923 ALL KA3RFE MDCBBS 910215 Attn New Packeteers pt8 Forwarding path: W3IWI KA4USE N4QQ N2GTE N3ETI KA3RFE MORE ON BULLETINS OK, now you know that there are local bulletins and flood bulletins. So what? Well, you also need to keep in mind what's appropriate for which catagory. With flood bulletins, there are local floods, regional floods, and national floods; each of which has a designated function and audience. A local flood bulletin would be one going to a very limited distribution area such as one city, or one county. A regional flood would be sent to a wider area, such as a state, or an ARRL region, or an FCC region. A national flood bulletin goes to BBSs throughout the country. Which flood header you choose to use should be appropriate to the purpose of your bulletin, and to the most logical audience. Example: Your club is going to hold a picnic and wants to invite hams from other clubs. What flood header do you use? National? No. Regional? Maybe. Local? Yes. (Why? If the picnic is to be held in Upper Lidville NY, nobody in Lower Coax MD cares...but someone in Middle Lidville NY might be interested.) Example: You have a Deluxe Gee-whiz Whizbang Antenna Gizmo which you want to sell. You paid $20 for it, and want to sell it for $10. Which flood header to use for this? National? No. Regional? No. Local? Yes. (Why? If you use the national or regional floods, the shipping charge to send the thing to anywhere will be almost as much as the asking price...so any buyer for it will want to pick it up, and prob ably wont want to drive more than 30 minutes to get it.) With "for sale" bulletins, you should keep in mind that the item MUST be ham-radio-related for it to be legal under part 97.113. You should also keep in mind that there are many sysops who refuse to carry or forward "for sale" bulletins. You should check with your sysop about this prior to entering the bulletin, or download his "Info" text, where many of them keep their bulletin-forwarding policy. Example: Your club will be holding a hamfest. You want to send a bulletin out to announce it. Its a one-day affair with no programs. Which header do you use? National? No. Regional? Yes. Local? Yes. (Why? The information is of regional interest, but not of national interest. Nobody in California is going to travel to a one-day hamfest in Maryland. So, you see that the content of your bulletin will determine which header to forward it to. You need to excercise some judgement and common-sense in addressing the bulletin. (more in Part 9) 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5730 B# 2328 ALL KA3RFE MDCBBS 910215 Attn New Packeteers pt9 Forwarding path: W3IWI KA4USE N4QQ WA3ZNW NB3P KA3RFE THE NATIONAL FLOODERS There are several varieties of National Flood Headers, all of which do the same thing: They go nation-wide. Three of the most common headers are "USA" "ALLUS" "ALLBBS". There are others, but those three show up more often than the others. What bulletins are appropriate for nation-wide forwarding? This question is continually debated among users and sysops alike. Ask 100 hams and you get 100 different answers. We CAN however use some judgement and common sense and come up with useful criteria. Many bulletins sent via the national floods are inappropriate in one sense or another. It's not unusual to see hamfest announcements going out nationwide, and its obvious that a national audience is not appropriate. It's also common to see someone selling some small piece of gear nationwide. As pointed out earlier,it makes little sense to put a national bulletin out to sell something small. The same also holds true for real big things, like towers. If you send a national bulletin out selling a tower, you'd better be prepared to package it for shipping...and wouldnt you rather the buyer pick it up?. Another point, with "sale"-type bulletins: it's common to see bulletins advertising stuff for sale which is in no way ham-related. FCC part 97.113 clearly states the item being sold MUST be ham-radio- related gear. Also, you must ask yourself if the bulletin could in any way be construed as "business" comms. You should check with your sysop to see what his policy is regarding national flood bulletins, since almost every sysop has differing criteria. If you exercise good judgement and common sense in sending national flood bulletins, you can't go wrong. Oh, one last thing....If you are unsure of the legality of your bulletin, its best not to send it at all. 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5734 B# 1881 ALL KA3RFE MDCBBS 910215 Attn New Packeteers pt 10 Forwarding path: W3IWI N4QQ WA3TAI WA7NTF KA3RFE HOW TO GIVE YOUR SYSOP ULCERS 1) Never kill your mail. Let your read-but-not-killed messages accumulate on the BBS. 2) Assume (wrongly) that the sysop will kill your messages for you. 3) Never read or download the documentation for the BBS. 4) Dont pay any attention to your sysop's messages telling you how to use the BBS and continue along your merry way with your mistakes. 5) Assume (wrongly) that any message you enter in error will be corrected by the sysop. 6) Complain long-and-loudly when the BBS goes down, but never, ever offer any support for system upkeep...monentarily or sweaty. (The majority of BBS systems are operated by individual hams, not clubs...and support for those systems usually are borne by the individual hams themselves with no help from the users...so, if you want to see the system stay up, HELP OUT!) 7) Never learn how to correctly enter NTS traffic on a packet BBS. Send traffic any old way....regardless of whether its sent in the right format or not...then bitch when the traffic never gets delivered at the end point because the traffic handlers cant figure out where it goes. 8) Send illegal bulletins. Eventually you will be caught, and you and your sysop will get fined. Your sysop will not appreciate that and he will lock you out of the BBS, might bomb your shack, and will be sorely tempted to put pins through your coax. This is known as the "WA3QNS EFFECT". 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA *********************************************************************** Here are the latest (and last, according to Pete) installments of the Attention New Packeteers Guide. For those that desire all 15 parts, they are available as one crudely merged, unformatted ASCII text file (hey, I've got a job, a life, and a girlfriend too, you know!) from me via E-mail. If I get mondo requests (i.e. >> 20 or so) I may consider a repost in a month's time or so. As always, the Guide is not my creation, it is that of Pete, KA3RFE, and all questions/comments/criticisms should be directed at him via AMPR KA3RFE@KA3RFE.MD.USA. Enjoy! 73, Paul W. Schleck, KD3FU ACMNEWS@zeus.unomaha.edu uunet!unocss!zeus!acmnews 137.48.1.1 ps67@umail.umd.edu uunet!mimsy!umail!ps67 128.8.10.28 ********************************************************************** MSG # TR SIZE TO FROM @BBS DATE TITLE 5766 B# 1678 ALL KA3RFE MDCBBS 910217 Attn New Packeteers pt11 Forwarding path: W3IWI WA3ZNW NB3P KA3RFE BEACONING It seems like the first thing a new packeteer does is send out beacons announcing to everyone that his/her packet station is on the air. That's understandable, but not a very nice thing to do. Beacons from private mailboxes just take up air time and on a busy channel, they just choke the frequency so badly that thruput gets very, very, slow. The best thing to do if you leave your stattion up for mailbox connects, is just keep the radio and tnc on without beaconing it. Why? What's the best way to see if a station is on the air?? Try to connect to it! What can be simpler? Leave the beacons turned off. Back in the early days of packet when there were not many stations, a beacon made sense. Now, however, all a beacon does it take up air time, especially if the beacon is being digipeated from various nodes or digi's. A while back, I observed a beacon from one digipeater being digipeated by 3 nodes and 2 digis. That's going overboard. I watched one digipeater being repeated by 4 other digipeaters each of which could hear each other. An utterly useless application of digipeating which only grabbed air time which coulda been used by other stations. So, the bottom line on beaconing is that its not all that of a good use of air time and it's sometimes abused. 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5794 B# 2613 ALL KA3RFE MDCBBS 910218 Attn: New Packeteers pt 12 Forwarding path: W3IWI N4QQ N2GTE WB3V KA3RFE DIGIPEATERS AND NODES: Pt 1 A digipeater is a packet station which can repeat packet signals on the operating frequency the station is on. You use a digipeater by entering it's call in the connect request when you enter a message. For example: "C W3XYZ V K3LID". The "V" tells the tnc to connect to W3XYZ "via" K3LID digipeater. The digipeater can only work correctly if it can hear both your call and the destination call, and all the stations must be on the same frequency. Although its possible to use up to five digipeaters in a path, it's not a very good idea to use more than two digipeaters to reach your end-destination station. Why? Channel loading. Each packet your station sends out will be repeated by each digipeater until it reaches the destination station, and each ACK packet from the destination station will have to be repeated by the digi's until it reaches your station. If you use two digipeaters to reach another station, the channel will get three packets to reach the other station, and three packets back to your station from the destination station. (Three? yeah...your original packet, a packet from digi #1, another from digi #2 equals three packets...the original packet from the destination station gets repeated by digi #2, then digi #1, which equals three more.) So, if you send a message over 2 digi's, the channel will wind up handling SIX packets round-trip. This takes up a lot of air time, not to mention the time it takes to get the round-trip finished...and that's only for ONE packet and assuming no retries! Digipeaters can only work well if they can hear the other stations on each side of the link. If a digi can hear your station, but cannot hear the station identified in the "via" address, nothing will work, and air time has been taken up for no good purpose. Digipeaters are "dumb". They cannot shift frequencies or attempt to establish a connect on a different frequency path from the one it is working. The digi is stuck on that one frequency and can only send on what it hears. If the destination station cannot be heard by the digi, nothing happens, except that lotsa air time has been taken up by lotsa retries, leading to channel loading and QRM. (more) 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5820 B# 1877 ALL KA3RFE MDCBBS 910219 Att: New Packeteers pt 13 Forwarding path: W3IWI N4QQ WA3ZNW NB3P KA3RFE DIGIPEATERS AND NODES pt 2 NODES What's a node, anyhow? How does it differ from a digipeater? A node is something like a switchboard - that's not a very good analogy, but its close. A node takes signals from one station and "ports" those signals to another station. Sounds like a digipeater, doesnt it? In contrast to a digipeater, however, the node handles the ACKs between itself and the stations on each end, cutting down the number of housekeeping packets going over the air. The difference is that the connect from station A to the node is one link, and the connect from the node to station B is another link. It looks like this: Station A: => Node - Node => Station B (one link) Station B: => Node - Node => Station A (second link) or: Station A <==> Node <==> Station B The arrows indicate the ACK and traffic paths. The signal goes to the node, where it is ACKed by the node to Station A. The node then sends the signal to station B, where is must be ACKed by B. If B does not ACK the packet, the node keeps sending it until it exceeds its time-out value, then it breaks the link. How does it make it better than using a digi? Instead of 6 packets round trip, going thru the node only requires 4 packets...so traffic should, theoreticaly, be faster. This is only one aspect of using a node versus using a digipeater. Nodes can also do other things which make them very useful critters to have around. 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5835 B# 2602 ALL KA3RFE MDCBBS 910220 Att: New Packeteers pt 14 Forwarding path: W3IWI WA3ZNW N2GTE WA7NTF KA3RFE DIGIPEATERS AND NODES pt 3 Other features of nodes which make them very valuable, are their ability to operate on more than one frequency and "port" signals between them, and their ability to automatically route traffic from an orginating node and a destination node many miles away. There are many different types of nodes, and while they all do essentially the same things, there are differences in command structure and features, so I'm not going to go into commands used by nodes, except to say that they all have a "help" command, usually in the form of a question mark or "H". The ability of a node to operate on different frequencies means that traffic can be sent to a station far away and not on the same channel. If, for example, you are a Novice, you can legally get into a BBS on 2 meters by connecting to a node on 220. Of course the node must either hear that BBS directly or hears another node which can hear the BBS...and you have to know the destination node to get there. Nodes interconnect with each other. Its possible to connect to a node 2 or 3 hundred miles away, the traffic goes into what most people call "the network". Each node has a list in its memory of the stations it can hear directly, and those which it can hear via another node. The garbage characters you see on the screen from time to time is a node telling other nodes on the frequency what it has available. Its possible, for example to connect to a node in Annapolis, MD and enter a connect request for a node in Richmond, VA on an entirely different frequency...all of which will be handled by the "network" based on the lists kept in each node. One thing you must keep in mind, each "hop" over the network results in a time-bite...it takes time to get the frames through, and the more hops it has to take, the slower the flow of traffic. If you want to connect to a distant node, you do not have to specify the routing, nor do you need to manually connect to each node which is in-between. All you need to do is tell the node to connect to the destination node (assuming it knows about it...) and the network will route the request to the destination node using the best path. 73, Pete, KA3RFE KA3RFE@KA3RFE.MD.USA MSG # TR SIZE TO FROM @BBS DATE TITLE 5834 B# 2630 ALL KA3RFE MDCBBS 910220 Att: New Packeteers pt 15 Forwarding path: W3IWI WA3ZNW N2GTE WA7NTF KA3RFE LAST, BUT NOT LEAST... Feedback from users and sysops has been taken into account for this last (for now) part of the series. Here are some final thoughts: Instead of beaconing your personal mailbox, put a local bulletin on your "home BBS" telling everyone you're up. If you feel that you ABSOLUTELY have to beacon, no matter WHAT anyone else says: use the "beacon AFTER X" command instead of the "Beacon EVERY X". This will let you beacon without adding to the channel loading and congestion. (If you dont know what the difference is, you should read your tnc manual.) Choose ONE "home BBS" and stick with it. Multiple "home BBS's" just make your mail go into a ping-pong circuit. Don't play "BBS DX'ing". Dont use the nodes tables to see how far you can go on the network by trying to connect to a network BBS. Just about all BBSs have the same bulletins on hand, so going thru a bunch of nodes to reach a certain BBS is a waste of air time and a bad use of network resources. Dont try to download a long file from a BBS during peak traffic times. ( about 2100-2300) Make sure you use the correct Hierarchical-routing designator when addressing mail to an out-of-state BBS. (.#local.State.National, and make sure the periods are there!) Use the right bulletin header when sending bulletins. Keep in mind your intended target audience. Dont send club meeting announcements, novice class notices, hamfest information, and other items of stricly local interest via @USA or @ALLUS. Make absolutely certain that your messaage is legal. Its been suggested by some sysops that your only quarentee of "legalness" is to keep your bulletins STRICTLY AMATUER-RADIO RELATED! A bunch of sysops got into hot water with the FCC over a bulletin sent by a now-imfamous user which had absolutely nothing whatsoever to do with Ham Radio. Last of all: HAVE FUN! I hope these messages have been helpful to you. If you have any questions, feel free to send them to me. If I dont know the answer right away, I'll get it from somewhere ASAP. There are lots more areas I could cover, but this series was intended to get you up and running with basic packet. 73, Pete KA3RFE @ KA3RFE.MD.USA.NOAM