Let's say that you've decided to pursue CCVP certification, but you need some extra hands-on. You might want to set up a home lab. Some might suggest turning to an IOS emulator to practice anything IOS-related. However, building a home lab for the CCVP track isn't quite that simple. Specifically, you need to connect phones, analog circuits, and digitals circuits into routers. So, in my opinion, you need actual router hardware (in addition to an appropriate IOS image).
First, let's think about the voice ports you might need in your routers. There are three types of Cisco analog voice ports:
- FXS (Foreign Exchange Station) ports: Can connect to analog phones
- FXO (Foreign Exchange Office) ports: Can connect to telephone switches (e.g. a line coming in from your local central office)
- E&M (Ear and Mouth, Earth and Magneto, or rEceive and transmit): Can connect to existing E&M ports in a Private Branch Exchange (PBX). NOTE: If budget is a concern, you might want to omit E&M ports from your home lab.
Next, consider digital voice ports:
- T1 controller: Has 24 channels
- E1 controller: Has 32 channels (one of which is dedicated for framing and synchronization and another which is dedicated to signaling)
Another hardware consideration is whether or not to have Digital Signal Processor (DSP) resources in the router. For example, you could purchase various voice network modules that contain DSPs, and those DSP could be tasked with acting as conferencing or transcoding resources (as just a couple of examples). Adding DSPs could certainly bump up the overall investment in your lab. So, some candidates don't go for it.
There are many combinations and permutations that could be used to build a home lab, many of which are dictated by what equipment you already have on hand. So, to get your creative juices flowing, I thought I'd show you the home lab topology that I constructed. As a disclaimer, it doesn't do everything. It doesn't do transcoding, and it doesn't have ISDN, but it does a lot. First, check out the topology itself.
- The Cisco Unified Communications Server (UCM) is version 6.1. Even though Cisco doesn't support UCM running on VMWare, it will work for the most part in an isolated lab environment.
- Routers R1 and R3 are Cisco MC3810 routers that contain FXS, FXO, and E&M analog voice ports. They each also contain a T1 digital interface.
- Router R2 is a Cisco 2610 router containing an NM-2V (a network module that can accommodate two voice interface cards (VICs)) which contains a single VIC-2FXS (a voice interface card containing two FXS ports).
- Router R4 is a Cisco 2611-XM containing an NM-1V (a network module that can accommodate one VIC) which contains a single VIC-2FXS.
- The IP phone is a Cisco 7940G IP Phone.
- The two analog phones connected to the FXS ports are just basic single-line analog phones much like you would buy at your local department store.
In addition to the hardware (and again, the example provided is just one (non-perfect) home lab topology), there is the consideration of an appropriate IOS version. Fortunately, Cisco offers us a great tool for identifying the IOS needed to support specific features.
To illustrate, let's say that we wanted to make R2 in our topology act as a gatekeeper (which is a feature that it does perform in my home lab). First, we navigate to Cisco's Feature Navigator (www.cisco.com/go/fn), and click on the Search by Feature link. This opens up another window.
From this window, there is a dialog box from which you can select which feature(s) you're interested in. In our example, let's select High Performance Gatekeeper, and click the Add button to add the feature to the Selected Features pane.
Once we've selected our desired features, we click the Continue button. Then we drop down the Platform menu to select our router model (2610-2613 in our example).
We are then presented with a listing of IOS images that support our specified feature(s). Pay close attention to the required DRAM and Flash for the image, and make sure your router meets those requirements. Also, be sure you are licensed to use the image you select.
Hopefully, this short discussion has sparked a few ideas in your mind as to how you can construct your own CCVP home lab. Coming up in my next and final blog for the month will be an overview of Cisco's new CCNA Voice concentration.
See you then,