Troubleshooting VoIP in Converged Networks

Terry Slattery
Principal Architect

I recently did a recording for Cisco of a presentation that I’ve done at VoiceCon about troubleshooting VoIP in converged networks.   This recording, along with links to the audio files referenced in it, is available from the Cisco Learning Network web site at:

The Cisco Learning Network home page is at:

The slides may not be very readable in the presentation and if that’s important to you, then go to the Netcordia/Resources/Webinars web page to download a PDF of the presentation:

In the presentation I step through a set of common problems with VoIP, from adding a VoIP phone to a network to the causes of poor voice quality. I identify the problems that are typically encountered and how to troubleshooting them. Symptoms, causes, and remediation steps are described. In this presentation, I takes you through:

  • The processes of:adding a VoIP phone to a network
  • The types of problems that are typically encountered and how to begin troubleshooting them
  • Symptoms, causes, and remediation steps for typical VoIP network problems

Because there is more time in the recording studio than I have as a member of a panel at VoiceCon, I was able to expand on some of the trougleshooting topics.  So even if you’ve attended my talk at VoiceCon, you may benefit by watching the Cisco Learning Network video recording.  It is less than 30 minutes in length.


ps –  Since I first wrote this blog, I’ve been invited to do a half-day tutorial at the 2009 VoiceCon, March 30, 2009, in Orlando, FL.   The title is VoIP Troubleshooting, Management, and Metrics, which will be a more in-depth coverage of troubleshooting as well as a discussion of how to tell when things are not going well in your VoIP system.  The metrics can occasionally point out problems that have just started to surface and have not yet begun to affect your customers.  If the above video is useful to you, then you may want to consider attending the tutorial at VoiceCon.


Re-posted with Permission 

NetCraftsmen would like to acknowledge Infoblox for their permission to re-post this article which originally appeared in the Applied Infrastructure blog under


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Nick Kelly

Cybersecurity Engineer, Cisco

Nick has over 20 years of experience in Security Operations and Security Sales. He is an avid student of cybersecurity and regularly engages with the Infosec community at events like BSides, RVASec, Derbycon and more. The son of an FBI forensics director, Nick holds a B.S. in Criminal Justice and is one of Cisco’s Fire Jumper Elite members. When he’s not working, he writes cyberpunk and punches aliens on his Playstation.


Virgilio “BONG” dela Cruz Jr.

CCDP, CCNA V, CCNP, Cisco IPS Express Security for AM/EE
Field Solutions Architect, Tech Data

Virgilio “Bong” has sixteen years of professional experience in IT industry from academe, technical and customer support, pre-sales, post sales, project management, training and enablement. He has worked in Cisco Technical Assistance Center (TAC) as a member of the WAN and LAN Switching team. Bong now works for Tech Data as the Field Solutions Architect with a focus on Cisco Security and holds a few Cisco certifications including Fire Jumper Elite.


John Cavanaugh

CCIE #1066, CCDE #20070002, CCAr
Chief Technology Officer, Practice Lead Security Services, NetCraftsmen

John is our CTO and the practice lead for a talented team of consultants focused on designing and delivering scalable and secure infrastructure solutions to customers across multiple industry verticals and technologies. Previously he has held several positions including Executive Director/Chief Architect for Global Network Services at JPMorgan Chase. In that capacity, he led a team managing network architecture and services.  Prior to his role at JPMorgan Chase, John was a Distinguished Engineer at Cisco working across a number of verticals including Higher Education, Finance, Retail, Government, and Health Care.

He is an expert in working with groups to identify business needs, and align technology strategies to enable business strategies, building in agility and scalability to allow for future changes. John is experienced in the architecture and design of highly available, secure, network infrastructure and data centers, and has worked on projects worldwide. He has worked in both the business and regulatory environments for the design and deployment of complex IT infrastructures.