CME - Creating the Network

A big part of building a Call Manager Express PBX environment is creating the network. CME expects that you are going to run a VLAN'd network with a minimum of 3 VLANs: the Data, Voice and Management VLANs. It also expects that you are going to have inter-VLAN routing (routing between VLANs) and access to the Internet through the WAN interface.

The Data VLAN will carry the data traffic of the network. The Voice VLAN will carry the voice traffic which consists of the voice protocols for call setup (SCCP/SIP/H.323) and the audio transmission using RTP. The Management VLAN is a VLAN restricted to administrators, used for managing the network devices: routers and switches.

The following information assumes that you have an understanding of the Cisco command line up to CCNA 3 level.

VLAN - Virtual Local Area Networks - Virtual LANs provide a method of segragating traffic based on the type of traffic. This page provides general reference material about VLANs.

Creating the VLANs - This page walks you through the creation and configuration of VLANs on a Cisco switch. It also gives you the choice on configuring the port to the router to be configured either for interVLAN routing using a Layer 3 switch OR using a Router on a Stick.

Routing - This area provides a general discussion on several different methods for Inter-VLAN routing and concerns that we should know about when we route out to the Internet (WAN routing).

Creating the Layer 3 Switch InterVLAN Routing - This page walks you through the configuration of InterVLAN routing using a Cisco Layer 3 switch.

Creating a Router on a Stick InterVLAN Routing - This page walks you through the configuration of InterVLAN routing using a Cisco Router on a Stick.

Ideally, you would want to use a Layer 3 switch for inter-VLAN routing. It provides the best performance and is the proper way to do inter-VLAN routing. Another option, if you only have a Layer 2 switch, is to use the 90s technology of Router-on-a-Stick method. Your connection between the router and the switch will take a 40% performance hit using this method.

Creating a DHCP server - An important part of the network is the DHCP server. It allocates IP addresses and options to the devices on the network. The DHCP server can be located on a server, router or a switch. This page details the configuration of a DHCP server on a switch or a router.

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Copyright July 2013 Eugene Blanchard