Conversations with Experts™A Metanoia, Inc. Signature Series!

Designing for Off-Net Traffic? A Look at How Planning Tools Handle Peering Traffic
Analysis, and the Profusion of IPTV and Mobile Backhaul Traffic:

With with Dr. Dave Wang, CEO & Co-Founder, WAND

In the Capacity Planning Panel at NANOG52 (that was Chaired by Metanoia, Inc. Founder, Dr. Vishal Sharma) , an interesting question that emerged on the operator “wish list” was the ability of network planning and traffic engineering tools to assist with peering traffic analysis. Traditionally, the focus of a network planning and traffic engineering tool is to help the service provider perform tasks such as analysis, design, what-if investigation, and capacity planning & forecasting, for traffic that is flowing on the operator’s own network. In the simplest sense, operators have (or generate) an estimate of the traffic volumes in their network, and run these through the planning tool to model any number of metric change, failure, overloading, and new capacity deployment scenarios.

Peering traffic, however, represents traffic that is leaving the operator’s domain, and, in this sense, is “off-net” traffic. Nonetheless, changing internal metrics has an impact on the exit points of this traffic, and, likewise, a change in metrics in peer networks has an impact on the entry point(s) and corresponding volumes of traffic that an operator’s network receives from its peer networks. Since peer network metrics are typically not known within a service provider network, there are interesting constraints on the ability of planning tools to model such scenarios.

To discuss this issue, and to also talk about the impact that the growth in IPTV and mobile backhaul traffic is having on the capabilities and design of planning tools, we invited Dr. Dave Wang of WANDL, one of the pioneers in the network and capacity planning space, to participate in an episode of our signature series, “Conversations with Experts.” Dave shared some of his insights into of how peering traffic analysis may be done in planning tools, and a few of the intricacies involved.

Designing for Off-Net Traffic? A Look at How Planning Tools Handle Peering Traffic Analysis, and the Profusion of IPTV and Mobile Backhaul Traffic:
Dr. Dave Wang, CEO & Co-Founder, WANDL in Conversation with Vishal Sharma, Principal Technologist, Metanoia-Inc.


In this Conversations with Experts episode, we focus on peering traffic analysis and how that may be done in planning tools, with Dave Wang of WANDL. Dave first provides a brief look at the evolution of WANDL, one of the earliest network planning and capacity planning tool companies, from the early 1990’s to the present – going from modeling TDM and ATM networks to modeling IP/MPLS and Ethernet networks.

We then dive into the key issues in modeling peering traffic in modern planning tools. Dave first explains the difference between transit and peering, and then outlines some of the pre-requisites that are needed by an operator (and, of course, the network modeling tool) to help the operator model peering. The key issue is the determination of how and which exit points are impacted when an internal metric in a service provider’s network is changed. Similarly, a change in metrics in external networks will alter where and how much traffic enters a service provider’s network.

The ability to model peering traffic flow is also extremely valuable to today’s content providers, especially as they move more and more towards peering with various large and small operators. So, Dave shares his insights on this issue. Finally, we discuss how the growth in mobile backhaul traffic and the advent of IPTV services is imposing new requirements on planning tools, and what that means for planning tool evolution.

For more on WANDL, please visit


Dr. Dave Wang is President and Co-Founder of WANDL (Wide Area Network Design Laboratory), a premier planning tool vendor for IP, MPLS, and Ethernet networks, and one of the pioneers in the network planning and design space with its flagship NPAT (Network Planning and Analysis Tool) product.

At WANDL, Dave has played a major role in the design, development and evolution of NPAT, and is a renowned expert in the areas of ATM, Frame Relay, TDM and IP/MPLS-based networks, having contributed to each of these areas in his 25 year career at WANDL. Dave has, over the decades, worked closely with hardware and system vendors, such as Cisco, Juniper, Tellabs, Foundry Networks, to name a few, on routing, connection-admission control, and network stability issues. On the other hand, he has also worked with carriers, ISPs, and large enterprise customers of all shapes and sizes on countless network designs, and RFPs, advising them in the planning and analysis of WANs of all types, and enhancing the NPAT tool to meet diverse customer needs.

Over the years, Dave has been an invited speaker and panelist in innumerable industry events and multiple fora, such as NANOG, MPLS & Ethernet World Congress, MPLS (Washington, D.C.), FutureNet, APNIC, APRICOT, and WOCC (Wirless and Optical Communication Conf.).

Dave received a BS in Mathematics from the National Taiwan University in 1969, and his Ph.D. in Mathematics from the Massachusetts Institute of Technology (MIT) in 1973.


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