Knowledge Base

Title Authors Last Update Category
Presentation on the 10GEC Bob Noseworthy

Presented at the 10Gigabit Ethernet User Conference, Nov 1 2002

November 5, 2002 Tutorials
Proceedings of the 5th Annual Linux Showcase & Conference Ashish Palekar, Narendran Ganapathy, Anshul Chadda, Robert D. Russell

Design And Implementation Of A Linux SCSI Target For Storage Area Networks.

June 29, 2012 White Papers
PTP Background and Overview Jeff Laird

Terms used when discussing PTP

June 28, 2012 White Papers
QOS Over ADSL Praveen Reguraman

Today's digital economy, dominated and driven by the growing commercial outlook of the Internet, has stimulated the demand for broadband networking as well as Quality of Service (QoS) architectures to achieve application performance and user satisfaction. Asymmetric Digital Subscriber Line (ADSL) is gaining prominence as a cost-effective broadband access solution for high speed Internet access, being widely deployed nationwide. The promise and potential to handle applications like Video on Demand over ADSL has set the stage to engineer and evaluate QoS in ADSL systems. As a first step in this direction, the various issues applicable to QoS over ADSL are discussed and a test setup was developed to evaluate the QoS metrics with respect to the physical layer characteristics of ADSL systems. The results of the preliminary set of experiments and the insight gained from these will be presented along with recommendations for future work.

December 7, 2000 Theses
Quality of Service Testing Methodology Ankur Chadda

Typically, a network service provider offers best-effort service to customers and Quality of Service (QoS) is provided only by network over provisioning. When traffic bursts cause congestion, this default approach does not always provide an acceptable solution. As the trend in networking is convergence of voice, video and data, it is important to differentiate traffic into high and low priority classes through QoS mechanisms. To deliver differentiated QoS, the routers utilize classification and sometimes remarking of the traffic. Based on service agreements with the customer, a certain class of traffic is then given more resources by the router. Evaluation of the results of these methods and approaches on the network performance is very important to device designers, network evaluators, network administrators, network operators and others involved. To study the effects of QoS solutions/techniques on the traffic, methods for testing need to be developed. The objective of this thesis is to propose methods of measuring QoS metrics like throughput, latency, and jitter for different types of traffic through a device. Classification and remarking were observed to put extra load on a device. For some devices, the performance deteriorates when classification and remarking are enabled. Throughput was seen to drop for classification and remarking in some cases. In multiple instances, latency and jitter increased for classification and remarking. There are multiple ways of measuring jitter which were also discussed in the methodology development. It was also observed that some definitions which might seem better from a research perspective are not always available to measure or widely used in the industry. Based on the study it was concluded that service/network providers will have to take care while providing QoS to the customers in order avoid the scenarios discussed here.

December 13, 2004 Theses
Quartz Crystal Resonators and Oscillators for Frequency Control and Timing Applications - A Tutorial John Vig

This is a slide deck.
Chapter 1 (20 slides) provides an overview of clock synchronization applications.
Chapter 7 (11 slides) compares various types of oscillator.
Chapter 8 (33 slides) provides an overview of timekeeping.
The remainder of the 300 slides describe engineering details of quartz oscillators.

October 22, 2014 External Links
Radio Frequency Interference and Capacity Reduction in DSL Padmabala Venugopal (UNH-IOL), Michael J. Carter, Scott A. Valcourt

The issue of radio frequency interference in Digital Subscriber Line (DSL) networks is of particular concern in urban areas with many strong radio sources nearby. This paper investigates in detail the mechanisms underlying the capacity reduction due to the presence of radio frequency signals from Amplitude Modulated (AM) broadcast stations in an ADSL network. An ADSL system, channel, and radio frequency interference noise were simulated in MATLAB. The capacity reduction due to different Radio Frequency (RF) ingress conditions was studied. Spectral Spreading of the RF interferer, as suggested by Harris et al [1], is a primary cause of capacity reduction, but only at long loop lengths where the signal to Gaussian noise ratio is very low.

November 4, 2002 White Papers
Radio Frequency Interference in DSL and Capacity Reduction Padmabala Venugopal

The issue of radio frequency interference in Digital Subscriber Line (DSL) networks is of particular concern in urban areas with many strong radio sources nearby. Prior work by Harris et al showed drastic decreases in DSL link capacity with a narrowband AM interferer. The purpose of this thesis was to investigate in more detail the mechanisms underlying the capacity reduction observed by Harris. In this thesis, an ADSL system, channel, and radio frequency interference noise were simulated in MATLAB. The capacity reduction due to different RF ingress conditions was studied. It was found that a narrowband interferer does not cause a drastic decrease in capacity if time and frequency domain equalizers are employed in the receiver. Contrary to Harris?s suggestions that spectral spreading of the interferer is the primary cause of capacity reduction, it is shown in this thesis that such spreading is a secondary effect and that the unequalized channel is the predominant source of capacity reduction.

April 23, 2002 Theses
Routing OSPFv2 Guide UNH-IOL

This document describes the OSPF Protocol.

July 21, 2008 Tutorials
RSP: Development of an 802.11 MAC Richard L. Lynch

In the growing world of ubiquitous networking, people often take for granted that interoperability exists between their network devices and the networks they are connecting to. Consortium vendors and international standards bodies are formed to establish standards on how devices should behave if they wish to communicate with each other. However, verifying conformance to these standards is no trivial task. The RSP was developed to add to the Wireless LAN Consortium's testing capabilities. The RSP has the capability of reacting to wireless traffic in a manner that tests a device's handling of uncommon, but very important conditions. The RSP Consists of an 802.11 MAC'less card from Intersil, interfaced to an Altera programmable logic device, which in turn communicates with a PC through a USB microcontroller.

September 18, 2014 White Papers