We all know that a network allows us connectivity with other stations. To aid our analysis, consider what happens when you want to leave a message to a friend of yours who lives some distance away from you. If you are in a typical packet radio situation, you may have 2 or 3 ways to do this:
1) You can connect to your local BBS and type in a message (if you both have access to a BBS). While other stations do the work, you have to remember his BBS address, you have no time to correct spelling errors and word your message properly.
2) You can connect up to his mailbox and leave a message there. Of course, you would have to navigate through a series of nodes to get to his mailbox. And if his station is not active, you have wasted your time. If you have a shaky path to any node in the circuit, you may suffer sudden disconnection and your message is lost in the ether. You will have to try another time. Again, you have no editing capabilities.
3) You could also leave a message in your mailbox, or another friend's mailbox. Of course, your mail recipient must remember to check for the mail (just like the BBS example above). If you choose to leave a message in your friend's mailbox, you also have to remember node aliases, the best route to take, and might have to wait for the right time of day to make a connection.
To sum it up, the process looks like this:
1) Connect to your local LAN node.
2) Gain access to the network.
3) Know the alias of his LAN node.
4) Deal with any nodes on the backbone making shaky connections.
5) Segment your connection circuit if there are any shaky paths.
6) Connect to his LAN node.
7) Connect to his mailbox and leave a message.
This is a heck of a lot of thought and human intervention required for a system that is run by computers! In contrast, consider what happens if you E-Mail one of your friends on the Internet:
1) You dial-in to an Internet service provider, and leave a message.
2) Your friend dials into his internet service provider and picks up his message.
It can be made even simpler. Some folks have their computers set up to automatically connect up to the service provider to send and collect E-Mail. Wouldn't it be nice to do that on Amateur Packet Radio?
Well, it is feasible, and many people do it right now with packet radio E-Mail. The secret is to have an advanced mail system and an open, transparent network at your disposal, as the Internet is. What do we mean by an open, transparent network?
Consider all of the stuff that goes on behind-the-scenes when making any kind of connection on the Internet, for any purpose. An excellent example of this is what happens when a person is "Web Surfing". When a person connects up to a "Web Site", he or she has no knowledge of how the data gets to or from this site. All they have to know is "//www.bogus.com", an internet address. This is a transparent connection, computers that do the routing and relay of the data are not seen by the user.
In a global computer network, there is likely to be a significant amount of network activity just to allow someone to connect up to this web site. This network is also open to a number of different protocols. The protocol used in this case is http, used for transferring the hypertext present in most web pages.
Contrast this with what you had to go through to get a message to your friend. There is a lot to know, and a lot to do. You have to know details about your friend's station and the network that the average Internet user doesn't ever worry about. So in order to make our mail system more "automatic", we need the following :
1) A way to send mail with maximum convenience, preferably without ever "leaving our own station".
2) A mail system that knows who the recipient of the mail is.
3) Mail systems that know how to work with a network.
4) An open network - capable of handling a protocol used by a "smart" mail system that works with the network.
5) Network transparency - packets of any kind are routed to their destination without human intervention.
6) Some method of receiving the mail and possibly storing it.
7) Ability to collect the mail in a convenient fashion.
Amateur Packet Radio has tried to accomplish this in a variety of ways. It has always been the vision of packeteers to have "door-to-door" mail delivery. While we will explore ways to get closer to this with our existing situation, we will not see mail fully automated with what we are using now. Although we would like to think of our current network node system as "auto-routing", it really is not always very efficient when we ask it to do this. In addition, some of our network nodes will not pass data that is sent using protocols other than Net/Rom and AX.25 (remember our discussion of how some protocols are not well suited for some tasks, but prefectly to others).
I have used mail as an example of one process that might be able to use a different protocol. There are other packet radio functions that may well be able to use protocols different that what we are using now. When discussing a digital radio network, we can further break a network system down to a few basic functions we will discuss in the next installment. These can be described as:
1) A originator of data.
2) A Network Interface Host Computer (comparable to a network node we now use, but more functional and automatic).
3) A transparent Auto-Routing network requiring no user knowlege or intervention.
4) Another Network Interface Host Computer at the destination.
5) A receiver of data. Actually, origination and reception of data can be combined into the function of Network Interface Host Computers, further eliminating two of these functions.
Next time we will dissect the functions of each of these parts of our radio network.
On to Part 25 - TCP/IP and Future Packet
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