docs: active channel description (#787)

* docs: adding active channels explanation

* change ordering

* updating config and adding more docs

* Update docs/app-modules/interchain-accounts/active-channels.md

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

* Update docs/app-modules/interchain-accounts/active-channels.md

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

* Update docs/app-modules/interchain-accounts/active-channels.md

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

* Update docs/app-modules/interchain-accounts/active-channels.md

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

docs/.vuepress/config.js

@@ -121,6 +121,11 @@ module.exports = {
                   directory: false,
                   path: "/app-modules/interchain-accounts/auth-modules.html"
                 },
+                {
+                  title: "Active Channels",
+                  directory: false,
+                  path: "/app-modules/interchain-accounts/active-channels.html"
+                },
                 {
                     title: "Integration",
                     directory: false,

docs/app-modules/interchain-accounts/active-channels.md

@@ -0,0 +1,25 @@
+<!--
+order: 3
+-->
+
+# Understanding Active Channels 
+
+The Interchain Accounts module uses [ORDERED channels](https://github.com/cosmos/ibc/tree/master/spec/core/ics-004-channel-and-packet-semantics#ordering) to maintain the order of transactions when sending packets from a controller to a host chain. A limitation when using ORDERED channels is that when a packet times out the channel will be closed. 
+
+In the case of a channel closing, a controller chain needs to be able to regain access to the interchain account registered on this channel. `Active Channels` enable this functionality. Future versions of the ICS-27 protocol and the Interchain Accounts module will likely use a new 
+channel type that provides ordering of packets without the channel closing on timing out, thus removing the need for `Active Channels` entirely.  
+
+When an Interchain Account is registered using the `RegisterInterchainAccount` API, a new channel is created on a particular port. During the `OnChanOpenAck` and `OnChanOpenConfirm` steps (controller & host chain) the `Active Channel` for this interchain account
+is stored in state.
+
+It is possible to create a new channel using the same controller chain portID if the previously set `Active Channel` is now in a `CLOSED` state. This channel creation can be initialized programatically by sending a new `OnChanOpenInit` message like so:
+
+```go
+	msg := channeltypes.NewMsgChannelOpenInit(portID, string(versionBytes), channeltypes.ORDERED, []string{connectionID}, icatypes.PortID, icatypes.ModuleName)
+	handler := k.msgRouter.Handler(msg)
+```
+
+Alternatively, any relayer operator may initiate a new channel handshake for this interchain account once the previously set `Active Channel` is in a `CLOSED` state. This is done by initiating the channel handshake on the controller chain using the same portID associated with the interchain account in question.  
+
+It is important to note that once a channel has been opened for a given Interchain Account, new channels can not be opened for this account until the currently set `Active Channel` is set to `CLOSED`. 
+

docs/app-modules/interchain-accounts/transactions.md

@@ -1,5 +1,5 @@
 <!--
-order: 5
+order: 6
 -->
 
 # Transactions