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- INTRODUCTION TO PACKET RADIO - PART 17 - by Larry Kenney, WB9LOZ
-
- How did you do on the review quiz in the previous part of this series?
- If you haven't taken it, you might want to read part 16 and take the quiz
- now before reading any further.
-
- Here are the correct answers and the series part numbers where you can
- read more about the subject:
-
- 1 - Answer C is correct. The three TNC modes of communication are Command,
- Converse and Transparent. Command mode is for communicating with the TNC.
- The Converse mode is for normal QSOs, connects to a BBS or mailbox, etc.
- and Transparent mode is used for binary file transfer. (Part 2)
-
- 2 - The UNPROTO command is used for setting the transmit path for both
- beacons and CQs. (Parts 3 and 13)
-
- 3 - The CHECK command is used for setting a timeout value in your TNC.
- If set to a value other than zero, the TNC will attempt to recover a
- connection after a certain specified time if nothing is received from the
- other station. This command is used in combination with the AX25L2V2
- command. (Part 13)
-
- 4 - The MCON command (Monitor while CONnected) is used to monitor other
- traffic on the frequency while you're connected to another station.
- (Part 3)
-
- 5 - When monitoring, the asterick indicates the station that you actually
- hear the packet from. The MRPT command must be ON for the monitor display
- to show digipeaters. (Part 2 and 3)
-
- 6 - The packet node network improves communications because packets are
- acknowledged from your station to the first node, and then node to node
- to the destination. A packet doesn't have to reach the destination
- before an ack is returned. (Parts 4, 10 and 11)
-
- 7 - When using the node network (no matter who you're connected to) you
- disconnect by going to command mode on your TNC and entering a D, just like
- at other times. The fact that you're using several nodes or are connected
- to a distant station makes no difference. The network will take care of
- disconnecting all stations and links. (Parts 4, 10 and 11)
-
- 8 - N6ZYX-2 would appear as N6ZYX-13 if he connects to you using a node.
- The nodes change the SSID using the formula 15-N. (Part 10)
-
- 9 - The two most probable causes for a packet not to get through are
- collisions with other packets on the frequency and noise due to weak
- signals. (Part 15)
-
- 10 - BBS commands:
- a. To receive a list of messages: enter L
- b. To download a file in the General (G) directory called
- FCCEXAMS.89, you'd enter DG FCCEXAMS.89
- c. To enter a private message to Jim, WA6DDM: SP WA6DDM @ W6PW.CA
- (The "@ W6PW" is not needed if you're using the W6PW BBS.)
- d. To read message 7134 with headers: RH 7134
- e. To find out what stations were heard on port B of the BBS, you'd
- enter JB
- (Parts 5, 6, 7 and 8)
-
- 11 - If you wanted to send an NTS message to Tom Smith, 123 Main Street,
- in Keene, NH 03431, you would enter the following at the BBS prompt >
- ST 03431 @ NTSNH (Parts 6 and 12)
-
- 12 - A message with a STATUS of BF means that the message is a bulletin
- and that it has been forwarded to all stations that are supposed to
- receive it from the BBS you're using. (Part 8)
-
- 13 - Answer D is correct. The date/time shown on a message when it's
- listed is the time the message was received at the BBS you're using.
- Please note that the date/time of a message indicates whatever time the
- BBS your using is set to, and that could be local time or zulu time, UTC,
- GMT, or whatever. Most BBSs are now set to zulu time (UTC, GMT), but a
- few still use local time. When you read a message, you should be able to
- read the date and time the message was written from the message header.
- (Part 8)
-
- 14-To find the call of the HOME BBS of your friends, use the White
- Pages Directory. If the BBS you're using has the WP feature enabled,
- you will find the I command to be useful, otherwise send an inquiry
- to WP. (Part 9)
-
- 15-The maximum value for MAXFRAME is 7. MAXFRAME is the number of packets
- transmitted by your TNC contiguously, and the number of unacknowledged
- packets the TNC can have outstanding. You decrease MAXFRAME when the
- conditions are poor. Your TNC will send fewer packets at one time, so
- there will be less information to collide with other packets on the
- frequency and less chance of information being wiped out by noise.
- (Part 14)
-
- There is no passing grade on the quiz. It was designed for you to check
- your general packet knowledge, and you'll have to be your own judge of that.
- I hope you did well on it!
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