Make federate.md more of a sumary of the steps to follow to set up replication

docs/federate.md

@@ -1,30 +1,41 @@
-Setting up Federation
+Setting up federation
 =====================
 
 Federation is the process by which users on different servers can participate
 in the same room. For this to work, those other servers must be able to contact
 yours to send messages.
 
-The ``server_name`` configured in the Synapse configuration file (often
-``homeserver.yaml``) defines how resources (users, rooms, etc.) will be
-identified (eg: ``@user:example.com``, ``#room:example.com``). By
-default, it is also the domain that other servers will use to
-try to reach your server (via port 8448). This is easy to set
-up and will work provided you set the ``server_name`` to match your
-machine's public DNS hostname, and provide Synapse with a TLS certificate
-which is valid for your ``server_name``.
+The `server_name` configured in the Synapse configuration file (often
+`homeserver.yaml`) defines how resources (users, rooms, etc.) will be
+identified (eg: `@user:example.com`, `#room:example.com`). By default,
+it is also the domain that other servers will use to try to reach your
+server (via port 8448). This is easy to set up and will work provided
+you set the `server_name` to match your machine's public DNS hostname. 
+
+You will also need a valid TLS certificate for this `server_name` served
+on port 8448 - the preferred way to do that is by using a reverse proxy,
+see [reverse_proxy.md](<reverse_proxy.md>) for instructions on how to
+correctly set one up.
+
+In some cases you might not want Synapse to be running on the machine that
+has the `server_name` as its public DNS hostname, or federation traffic
+to use port than 8448 (e.g. you want to use `example.com` as your `server_name`
+but want Synapse to be reachable on `synapse.example.com:443`). This can
+be done using delegation, which allows an admin to dictate where federation
+traffic should be sent, see [delegate.md](<delegate.md>) for instructions on
+how to set this up. 
 
 Once federation has been configured, you should be able to join a room over
-federation. A good place to start is ``#synapse:matrix.org`` - a room for
+federation. A good place to start is `#synapse:matrix.org` - a room for
 Synapse admins.
 
 ## Troubleshooting
 
-You can use the [federation tester](
-<https://matrix.org/federationtester>) to check if your homeserver is
-configured correctly. Alternatively try the [JSON API used by the federation tester](https://matrix.org/federationtester/api/report?server_name=DOMAIN).
-Note that you'll have to modify this URL to replace ``DOMAIN`` with your
-``server_name``. Hitting the API directly provides extra detail.
+You can use the [federation tester](<https://matrix.org/federationtester>)
+to check if your homeserver is configured correctly. Alternatively try the
+[JSON API used by the federation tester](https://matrix.org/federationtester/api/report?server_name=DOMAIN).
+Note that you'll have to modify this URL to replace `DOMAIN` with your
+`server_name`. Hitting the API directly provides extra detail.
 
 The typical failure mode for federation is that when the server tries to join
 a room, it is rejected with "401: Unauthorized". Generally this means that other
@@ -36,8 +47,8 @@ you invite them to. This can be caused by an incorrectly-configured reverse
 proxy: see [reverse_proxy.md](<reverse_proxy.md>) for instructions on how to correctly
 configure a reverse proxy.
 
-## Running a Demo Federation of Synapses
+## Running a demo federation of Synapses
 
 If you want to get up and running quickly with a trio of homeservers in a
-private federation, there is a script in the ``demo`` directory. This is mainly
+private federation, there is a script in the `demo` directory. This is mainly
 useful just for development purposes. See [demo/README](<../demo/README>).