VOIP HOME LAB - Part 1.5.1 Open vSwitch Configuration - Introduction

So far we have installed Windows 7 and Linux Core on VMware Workstation virtual machines. We want to connect these virtual machines into our VoIP home lab. To do this a central connection point must be deployed on the computer where virtual machines are installed. The point must be able to assign traffic from virtual machines to different VLANs and tag traffic with correct VLAN header before it sent to the rest of our network via trunk port.

One of the products that meet these requirements is Open vSwitch project. It is a virtual switch that can be installed on any Linux OS. It offers many features that can be found in modern hardware switches. Open vSwitch installation on Debian Linux is explained here. Follow the tutorial and install Open vSwitch on your Debian Linux distribution.

We will use Open vSwitch to connect the virtual machines into our voice lab network infrastructure. At the moment we have two virtual machines ready to connect to the network.

A virtual machine with installed Core Linux represents Linux workstation and will be connected to the Openvswitch port with configured Data VLAN 11. A network topology diagram is shown here. Core Linux installation on VMware Workstation is discussed here.

A virtual machine with installed Windows 7 and Cisco IP Communicator - CICP will be connected to the Openvswitch port with configured Voice VLAN 10. This is not a solution that follows Cisco design recommendation. In fact, traffic from Windows 7 workstation should be also assigned to the data VLAN 11. Only voice traffic generated by Cisco IP Communicator should be assigned to voice VLAN 10. The reason why we are going to mix voice and data traffic generated by Windows and CIPC is that Openvswitch does not support protocol that informs CICP about voice VLAN configured on switchport. In a Cisco environment a Cisco switch announces voice VLAN ID to Cisco IP phone via CDP protocol. Thanks to this information, Cisco IP phone can tag its traffic with correct VLAN ID. Untagged traffic received on switchport is automatically assigned to data VLAN.

Unfortunately, Openvswitch  has no CDP protocol implemented. Unlike hardware Cisco IP phone, CIPC lacks a configuration option that allows to set voice VLAN manually - parameter Admin VLAN ID. For this reason I have decided that traffic from Windows and CIPC belong to the same voice VLAN 10. As we said before, data traffic will be generated by Core Linux installed on VMware virtual machine.

We will also configure Openvswitch to connect a virtual machine with installed Cisco Unified Communications Manager - CUCM. This virtual machine has not been deployed yet. CUCM will be installed on that VM after we configure all network devices. The virtual machine will be connected to Openvswitch port with configured management VLAN 100 as it is shown here.

As we have mentioned before, a trunk port must be configured on Openvswitch that connects virtual machines to the rest of our network. The trunk port carries VLAN traffic and connects host computer to Cisco Catalyst 3550 switch.

Catalyst 3550 is connected via its port Fa0/24 to the wan port of router Belkin N+. Belkin router is SOHO that connects home network to the Internet. A static default route configured on Catalyst points packets that do not match specific routes in Catalyst routing table to the Belkin router so packets can reach the Internet.

Continue with Openvswitch and VMware Workstation configuration.


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