Docs at CacheTorrent.

docs/cache.md

@@ -2,12 +2,22 @@
 
 ![ ](pics/cache.png)
 
-The general idea of the **CacheTorrent** protocol is assigning the role of leaders to a percent of the peers. Each Leader will act as a unidirectional cache for downloading in each autonmous system. On one hand, a Follower will have to connect to a Leader in order to download a piece. On the other hand, a Follower can upload directly to another Leader in a different autonmous system.
+The general idea of the **CacheTorrent** protocol is assigning the role of leaders to a percent of the peers. Each Leader will act as a unidirectional cache for downloading in each autonomous system. On one hand, a Follower will have to connect to a Leader in order to download a piece. On the other hand, a Follower can upload directly to another Leader in a different autonomous system.
 
 ### Implementation
 
 We extend the BitTorrent protocol by adding components on top of it. We decorate a BitTorrent **Peer** as follows:
-- **Peer** - a CacheTorrent wrapper over a BitTorrent peer
+- **Peer** - a CacheTorrent wrapper over a BitTorrent peer; it has a *node* filed
+- **Leader** - a wrapper over a BitTorrent peer and it can sit on top of a *node* field
+- **Follower** - a wrapper over a BitTorrent peer and it can sit on top of a *node* field
+
+The **Follower** does not have many modifications, having less capabilities. The **Leader** replaces has the following components:
+- **CacheDownload** - a Download components which forwards uses a **Forwarder** and a **Picker**
+- **CacheUpload** - an upload component which uploads only if it has the piece
+- **Picker** - a wrapper over a BitTorrent Picker which selects a piece for a Leader by taking into consideration the requests made by Followers
+- **Forwarder** - a structure which forwards messages received by a Leader towards its followers
+
+To see more implementation details, take a look at the **godoc**.
 
 ### Message Types