Is it possible to build a voice lab without actual hardware? The answer is yes and no. You can build a very good lab using GNS3 and VMWare but it is not possible to build a complete lab. The underlying emulation engine for GNS3 (dynamips) does not support digital signal processors (dsps) or voice cards.

Over the next few months, I will show you how to build a very good lab without any hardware. If you want a more complete lab, you will need to obtain at least one router with dsps and voice cards. I have a 2611XM router with DSPs, a vic-2fxs card, a vic-2fxo card and an ATA-186.



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Disclaimer and Due Credit:

This tutorial series is heavily based on by Jayanm of Chicago, IL.  Jaynam has obtained the following Cisco Certifications: CCIE (Voice) – CCVP – CCSP – CCNA – CQS (PIX,VPN,IDS) – VMWare Certified Professional.

I really appreciate the ground breaking research by Jaynam.

Updates and Videos in the series:

I will include future videos in this section as they are created. It is a good idea to bookmark this particular post or subscribe to our RSS Feed if you would like to keep up on all future tutorials.


I am using a fairly basic pc with a 3Ghz hyperthreading CPU and 2GB Ram. By today’s standards, it is nothing special.

Update 1/19/09: I have added Dell 750 server with 4GB RAM for virtual servers at the Headquarters location.

Optional Hardware

As I mentioned before, I have a 2611XM router with a couple voice cards and some dsps. This is not manditory but I will include this hardware with the lab series for those that would like to purchase the hardware to follow along.

Emulated Hardware

I will be emulating 3725 routers because they will be seen on the CCIE lab. Although the 3725s call for 256 MB requirements, I have found that they only actually use ~192MB ram on my PC.

Jaynam and others have opted to use 2691’s. You may find this works better for you also.


I have chosen to use Ubuntu Linux for my host operating system due to better performance over XP, stability, availability, ease of use and price.

Host OS: Ubuntu 8.0.4
PC Emulation: VMWare Server v1.0.6 or 2.x
Router Emulation: GNS3 v0.5 / v0.6
IOS: c3725-adventerprisek9_ivs-mz.124-15.T6.bin

What is possible without hardware?

It is possible to test lots of  different Cisco VOIP Technologies. Here is a short list. I am sure I will make mistakes with this list or leave things out. Feel free to email me or make a comment to help me get a more complete list.

Call Manager Features

  • Call Routing – Partitions, CSS, Time of Day routing, Route Groups, Route Lists, Route patterns, Translation Patterns, Line Groups, Hunt Lists, Hunt Pilots, 4 digit dialing
  • Media Resources – Software Based Media Resources only – Music on Hold, Software Conference Bridge
  • IP Phone registration and dialing
  • Redundancy – SRST, AAR
  • Call Admission Control – Locations based and Gatekeeper
  • Unity Integration
  • Extension Mobility
  • Attendant Console
  • IPMA

SIP Trunking offers free SIP trunks for voice labs.

IOS Features

  • Call manager Express
  • Gatekeeper
  • Digit manipulation
  • Auto Attendant
  • TCL Scripts
  • Voicemail Integration from CME to Unity
  • Frame Relay
  • Class of Restriction (COR)
  • SRST

What is not possible without hardware?

  • Xcoder registration and testing
  • Hardware based conference bridges
  • Router based MOH
  • voice port configuration
  • t.37 fax store and forward
  • Fax relay
  • MGCP
  • Anything related to hardware not emulated, VG248, ATA, CAT6500, Catalyst 3550 switch.


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