What is shn, md5, mkwact, etc?
What is a round administrator?
What are rounds?
How do I sign up for a round?
How does a round work?
What does an etree'er do?
What is a vine?
What does a vine "head" do?
What does a vine "member" do?
What does an audio CD "leaf" do?
What does a free-loader do?
Why does the sender pay for postage? Isn't that backwards?
What is a SHN CD? How is it different than an audio CD?
Wait, can you go over that again?

What is shn, md5, mkwact, etc?
The big problem with CD trading today is that it's too easy to get audio errors while copying. Digital audio is much harder to extract than digital data, and it's not uncommon to get some kind of error - in the form of a pop or a click - when you extract audio, or "rip," from a cd.

Therefore, DDS utilizes a lossless-compression system - called Shorten - to shrink full wave files to about 60% of their original size. Because this is a lossless system, the files you get when you decompress the shorten files (called shn files) are exactly the same as the original wave files. No pops or clicks.

To make sure the shn files that person A has are the same as the ones that person B, we use something called md5sum-checking. An md5 file is generated that verifies that the files are the same. If anything is changed since the md5 was generated, even the name of the file, it will not verify.

The best tool for working with all these files is the mkw audio compression tool (mkwact), a great program designed by Michael K. Weiss. It can be found at the DDS Software page.

What is a round administrator?
The round administrator is the person who is running the round. For the DDS Rounds 1-7, Mike Vernal and Allan Chen were the round administrators. For Round 8, it is Allan Chen.

What are rounds
DDS spreads shows in "rounds." We would call it a tree except that
1) it has multiple shows
2) it only loosely follows traditional "tree" structures and standards

How do I sign up for a round?
We send an e-mail to the mailing list and you fill out the form. If there is room in the round, then you are in. That's it. Please don't e-mail to ask how to join a round.

How does a round work?
There are different ways you can participate in a DDS round. You can be an etree'er, be a vine "head," be a vine "member," an audio CD "leaf," or be a free-loading downloader. The structure runs from top to bottom in that order - servers feed vines, which are made up on a head and several members. Vine members then have several audio CD leaves. Etc.

What does an etree'er do?
The top levels of DDS utilize an "etree" to spread the show out via high-speed internet connections. Basically, there are a small number of "seed servers" which are chosen by the round administrator and given the shows early on. Then, a level of etree'ers download the shows from these seed servers. If there is need or if there are enough people with high speed internet connections, another level of etree'ers might then download as well. The etree'er level of the round might be abnormally large - even 3 seed servers could easily send to 30-40 etree'ers. This is a quick and proven way of getting the shows to people.

Keep in mind that round administrators will usually be picky about the seed servers and etree'ers. Seed servers will usually be those who have been with DDS for some time and have made a lasting commitment to the effort. Similarly, because etree'ers need to be dependable, round administrators often will make seemingly arbitrary decisions on whether a person should or should not be an etree'er.

An etree'er may or may not be a vine "head" as well. Please see the section on vine heads and free-loaders for the two options.

What is a vine?
A vine is exactly what it sounds like - a linear path from recipient to recipient. The round makes stops at each waypoint on the vine, then continues to move along.

For DDS, this means that the round starts at the top, or "head" of the vine. The head then sends to the first vine "member." That person then sends to the next member, and etc. Each member, in turn, has a few audio CD "leaves." At the end of the vine, the last member sends back to the head - this is a "circular" vine. More details below.

What does a vine "head" do?
The vine "head" starts off the vine. The selection of vine "heads" is based on two things:
1) location. since there will be a lot of mailing back and forth, the round administrator will often try and keep vines close together, geographically, to keep the time it takes to mail something at a minimum.
2) reliability. as with etree'ers, it's important that vine heads be dependable.

The head will also be an etree'er - downloading from a seed server. The head then burns the SHN's onto CD (in data format, not as uncompressed audio). The head then mails the SHN CD's to the first vine "member." The _sender_ pays for postage (don't worry, it evens out in the end). At the end of the vine, the last vine member sends back to the head. That's it.

What does a vine "member" do?
A vine member is one of the stops along the vine. The vine member receives SHN CD's from the preceding person (which is either another member or the vine head). He/she then copies the SHN's onto his/her computer. He/she then _immediately_ sends the SHN CD's to the next vine member. The _sender_ pays for postage.

A vine member needs to make sure he/she has enough hard drive space for the SHN's and for the wave files as you decompress and burn. You _must_ send the SHN CD's to the next vine member after copying to your hard drive or things will move too slowly. That means that after you copy them to you hard drive you'll need to have the space to decompress, burn, decompress, burn, etc.

What does an audio CD "leaf" do?
A leaf is just like in a regular tree. Each vine member (but usually not vine heads) will have a few people to whom they will send audio copies of the round. These operate like B&P's or trades, whatever you want. Simple.

It is important that a leaf move quickly. If they are doing a B&P with their vine member, and the blanks aren't there when the member is ready to burn them, then the cd's might not be directly from the SHN's. A vine member cannot be expected to keep either the SHN's or the decompressed waves on their computer indefinitely, waiting for a leaf to send discs.

What does a free-loader do?
There are many people who will want the shows in a round but who don't feel like doing anything else. This is understandable, especially with the growth of self-serve servers and etc. Therefore, if someone just wants to download the show, they can do so by signing up as a "free-loader." The round will not be available for download until the round is at least 1/2 over. Free-loaders will download from a seed server or some other designated location.

Why does the sender pay for postage? Isn't that backwards?
As noted above, the sender in a vine always pays for postage. Usually, in trading, we have all gotten used to the recipient paying for postage, like a B&P. There are three reasons why the sender pays in DDS vines:
1) it's faster. you don't have to wait for postage to get to you.
2) it doesn't make sense to go the other way and have the recipient just send $3 or whatever in the mail. it's slower and it's illogical.
3) it all works out in the end. the vine is a circle - ever sender is also a recipient. if the sender _always_ pays for postage, then eventually they will also have someone else pay for postage to them.

What is a SHN CD? How is it different than an audio CD?
A SHN CD is a data cd of the shortened wave files. You just take the SHN's and burn them as data. An audio cd is made up of the wave files that you get _after_ you decompress the SHN's. If you were to burn audio files and send them along the vine, the whole point of using a lossless compression system is missed.

Wait, can you go over that again?
Here is an overview. A sample structure:
S - seed server
E - etree'er
H - vine head
M - vine member
L - audio cd leaf
FL - free-loader

S1 - kaiyen

S1.E1.H1 - Oktava Boy
S1.E1.H1.M1 - Sony Slave
S1.E1.H1.M1.L1 - Robby Rotel

S1.E1.H1.M2 - Tommy Tascam
S1.E1.H1.M2.L1 - Paul Plextor
S1.E1.H1.M2.L2 - Mary Mitsui

S1.FL1 - Frankie Freeloader

So. kaiyen gets the shows from the round administator. kaiyen runs a server or at least sets one up temporarily, and one of the people who download from him is Oktava Boy.

Oktava Boy is also a vine head. He makes SHN CD's and mails them directly to Sony Slave. Sony Slave then copies the SHN's to his hard drive and mails the CD's to the next member, Tommy Tascam. Tommy Tascam copies the SHN's to his hard drive and, since he is the last member, mails the CD's back to the head, which is Oktava Boy.

Both Sony Slave and Tommy Tascam have leaves. Sony and Tommy contact their leaves ahead of time and decide that they will do B&P's. So Robby Rotel sends B&P to Sony and Paul Plextor and Mary Mitsui send to Tommy. Sony and Tommy will first copy the SHN's to the hard drive and mail off the CD's, then make themself audio copies. As they are making themselves audio copies, they will make their leaves copies as well. If any of the leaves are too slow and Sony or Tommy could not make them audio copies directly from the SHN's, then they will copy cd's the "old," less reliable way.

Finally, Frankie Freeloader is going to download the round directly from the seed server - kaiyen - after the round has reached at least Tommy Tascam in the vine.