VoIP Troubleshooting at VoiceCon Fall 2007

Terry Slattery
Principal Architect

I’m doing a presentation at VoiceCon next week in San Francisco’s Moscone Center titled Troubleshooting IP Telephony Networks.

This presentation will be quite a bit different than other similarly titled talks I’ve seen. I’ll be talking about a number of common problems in VoIP networks. Each item is presented with a symptom and a corresponding set of problems that could cause that symptom. Of course, I also provide an idea of what correction needs to be performed.

I wanted to take the above approach, with details about a number of specific problems because other talks I had attended at a variety of seminars were rather vague. The speakers would describe symptoms in general terms and provide similarly vague solutions “You have to monitor X”, without providing enough information to create a solution. I’ve been guilty of it too. For example I’ve told people that they need to monitor QoS queue drops to identify when specific queues are dropping packets and when those packet drops are a problem. But knowing how to setup a system to monitor those queues (it’s not easy) and the meaning of packet drops in specific queues was missing. This may not be a good example because of the complexity of the solution, but it is representative of the hand-waving that occurs in many presentations.

While it is difficult to properly address troubleshooting in a 20-25 minute presentation, there are a number of common problems that can be adequately covered. If this presentation works out, I may plan to do a tutorial session and cover additional scenarios. Starting with a technical session will provide some useful initial feedback and may provide input that the conference organizers need to create a better session for the next conference.

It will be interesting to see how my presentation will be received and whether it provides useful value to people. If you’re attending VoiceCon, please stop by the talk (Wednesday afternoon at 4pm) and let me know what you think of it.



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 http://www.infoblox.com/en/communities/blogs.html


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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.