.. _lab_setup:

Hardware Setup of a VOLTHA Test Pod
===================================

Overview
--------

In a testing setup rather than using a real RG or BNG emulated ones are
deployed on a Linux development server:

- The ``RG`` can be emulated by an ``lxc`` container (from now on ``client``)
- The ``BNG`` can be emulated by a Linux server
- The ``AggSwitch`` is optional in a VOLTHA deployment.

.. figure:: ../_static/voltha_lab_setup.png
   :alt: VOLTHA Lab Setup

   VOLTHA Lab Setup

*The image above represents the data plane connections in a LAB setup.
It does not include the kubernetes cluster for simplicity.*

What you’ll need to emulate E2E traffic is:

- 1 x86 server with Ubuntu 16.04 and at least the following interfaces:

  - 1 1G Ethernet port
  - 1 10G Ethernet port (this can be a second 1G interface as long as you have a media converter)

Setting up a client
-------------------

The first thing you need to do is to install ``lxd`` on your server. To do that
you can follow `this guide
<http://tutorials.ubuntu.com/tutorial/tutorial-setting-up-lxd-1604>`_

Once ``lxd`` is successfully installed you need to initialize it with:

.. code:: bash

   lxd init

we recommend to use all the provided default values.

Once ``lxd`` is initialized you can create a container and assign a physical
Ethernet interface to the container:

.. code:: bash

   lxc launch ubuntu:16.04 <name>
   lxc config device add <name> eth1 nic name=eth1 parent=<physical-intf> nictype=physical

Where:

- ``name`` is the desired container name. The convention used to identify which
  RG container is connected to an ONU is to use the ONU serial number as the
  lxc container name.

- ``physical-intf`` is the name of the interface on the server where the ONU
  is physically connected

Once the container is created you can check it's state with with ``lxc list``:

.. code:: bash

   +---------------+---------+--------------------+------+------------+-----------+
   |     NAME      |  STATE  |        IPV4        | IPV6 |    TYPE    | SNAPSHOTS |
   +---------------+---------+--------------------+------+------------+-----------+
   | voltha-client | RUNNING | 10.63.3.144 (eth0) |      | PERSISTENT | 0         |
   +---------------+---------+--------------------+------+------------+-----------+

Please make sure the container has an assigned IP or we it won’t be able
to login and install the ``wpasupplicant`` tool inside the RG.

Once the container is running you need to enter it for configuration. To access
the container run: ``lxc exec <name> /bin/bash``

Once inside:

.. code:: bash

   # activate the interface
   ip link set eth1 up
   # install the wpasupplicant tool
   apt update
   apt install wpasupplicant

..

   NOTE: ``wpasupplicant`` is a Linux tool to perform 802.1X authentication.
   `wpasupplicant documentation can be found here
   <https://help.ubuntu.com/community/WifiDocs/WPAHowTo>`_.

Create a configuration file for ``wpasupplicant`` in
``/etc/wpa_supplicant/wpa_supplicant.conf`` with the content:

.. code:: text

   ctrl_interface=/var/run/wpa_supplicant
   eapol_version=1
   ap_scan=0
   fast_reauth=1
   network={
           key_mgmt=WPA-EAP
           eap=MD5
           identity="user"
           password="password"
           ca_cert="/etc/cert/cacert.pem"
           client_cert="/etc/cert/client.pem"
           private_key="/etc/cert/client.key"
           private_key_passwd="whatever"
           eapol_flags=3
   }

..

   NOTE: The configuration in this file is not really important if you are
   using the ``freeradius`` server provided as part of the VOLTHA helm charts.
   Do not worry if the certificates do not exist, they won’t affect
   authentication as that is password based.

At this point you’ll be able kickoff the authentication process (by
sending ``EAPOL`` packets into the system) with the command:

.. code:: bash

   wpa_supplicant -i eth1 -Dwired -c /etc/wpa_supplicant/wpa_supplicant.conf

If everything has been set up correctly, you should see output similar to this
in the VOLTHA logs:

.. code:: bash

   cord@node1:~$ kubectl logs -f -n voltha vcore-0 | grep -E "packet_indication|packet-in" | grep 888e
   20180912T003237.453 DEBUG    MainThread adapter_agent.send_packet_in {adapter_name: openolt, logical_port_no: 16, logical_device_id: 000100000a5a0097, packet: 0180c200000390e2ba82fa8281000ffb888e01000009020100090175736572000000000000000000000000000000000000000000000000000000000000000000, event: send-packet-in, instance_id: compose_voltha_1_1536712228, vcore_id: 0001}

Setting up an emulated BNG on Linux
-----------------------------------

The emulated BNG needs to perform only two operations: ``DHCP`` and
``NAT``.

To setup a NAT router on an Ubuntu 16.04 server you can look at this
tutorial:
https://www.nairabytes.net/81-linux/418-how-to-set-up-a-nat-router-on-ubuntu-server-16-04

To install a DHCP server you can follow this tutorial:
http://nairabytes.net/81-linux/415-how-to-install-a-dhcp-server-in-ubuntu-server-16-04

Once the ``DHCP`` server is installed, you need to configure it.

Create Q-in-Q interfaces
~~~~~~~~~~~~~~~~~~~~~~~~

On the interface that connects to the Agg Switch (upstream) you are
going to receive double tagged traffic, so you’ll need to create
interfaces to received it.

Supposing that your subscriber is using ``s_tag=111``, ``c_tag=222`` and
the upstream interface name is ``eth2`` you can use this commands to
create it:

.. code:: bash

   ip link set eth2 up
   ip link add link eth2 name eth2.111 type vlan id 111
   ip link set eth2.111 up
   ip link add link eth2.111 name eth2.111.222 type vlan id 222
   ip link set eth2.111.222 up
   ip addr add 10.11.2.254/24 dev eth2.111.222

Then you’ll need to tell the ``dhcp`` server to listen on that
interface, you can do that by editing the file
``/etc/default/isc-dhcp-server`` so that it looks like:

.. code:: bash

   INTERFACES="eth2.111.222"

..

   NOTE that you can list multiple interfaces, separated by spaces, in
   case you have multiple subscribers in your setup

In the ``/etc/dhcp/dhcpd.conf`` config file, configure the IP address
range to assign to the double tagged interface:

.. code:: text

   subnet 10.11.2.0 netmask 255.255.255.0 {
     range 10.11.2.1 10.11.2.100;
     option routers 10.11.2.254;
     option domain-name-servers 8.8.8.8;
   }