Knowledge Base

Title Authors Category Updated
Overview of Internet Protocol (Part 2) Ben Schultz

An overview of the workings of the Internet Protocol (Part 2) including specific IPv4 routing protocols.

Tutorials June 4, 2001
Overview of the Internet Protocol Ben Schultz

An overview of the workings of the Internet Protocol.

Tutorials June 4, 2001
Overview of UNH EXS for Programmers Robert Russell, Patrick MacArthur

The Extended Sockets API (ES-API) is a specification published by the Open Group that defines extensions to the traditional socket API in order to provide asynchronous I/O and also memory registration for Remote Direct Memory Access (RDMA). These two major new features enable programmers to take advantage of today's multi-core processors and RDMA network hardware, such as InfiniBand, iWARP and RoCE interfaces, in a convenient yet efficient manner.

Tutorials April 15, 2012
PCIe_Express_Overview Raju Mishra

Step by step overview on the PCIe Express.

Tutorials September 23, 2014
Performance Evaluation of TCP over IEEE 802.11 WLANs Sachin Goel

Transmission Control Protocol (TCP) is a communication protocol that is used to provide reliable data delivery between hosts. As TCP is the most highly used transport-layer protocol, many have worked on addressing the issue of performance. Performance issues have been studied in various environments, especially when using 802.11 Wireless Local Area Networks (WLANs). Wireless networks are prone to a higher number of packets loss and corruption. 802.11 WLANs have an equivalently fast acknowledgement mechanism as TCP to ensure reliability of traffic over it. This duplication of functionality between TCP and 802.11 WLAN creates unexpected behaviors that can result in high costs in terms of overall performance. A significant amount of analytical and simulation work has been done in the past to study the behaviour of TCP over 802.11 WLANs. The main contribution of this work is the analysis of TCP interaction in an 802.11 WLAN topology by using real commercial-grade equipments. A testing methodology is designed to do the quantitative performance evaluation in a network topology consisted of wired as well as a wireless connection. The methodology contains test scenarios with different configurable settings on an Access Point (AP) and various controlled impairments in the network topology such as latency, packet drop, noise interference, etc. The performance of TCP is measured in terms of the throughput. This work provides a comprehensive set of experiments to study the behaviour of TCP over 802.11 WLANs. The results can provide insight into the performance cost associated with TCP traffic on 802.11 WLANs under different network environments and configurations on the AP. The results of this work thus have a value to equipment manufacturers and network operators.

Theses September 1, 2006
Piecing Together the Performance Testing Puzzle Chris Brown & Tim Carlin, UNH-IOL

The latest Dark Reading Ezine focused on Security Testing, features a piece by the IOL "Piecing Together the Performance Testing Puzzle" on pg. 17 NetSecOPEN is developing more security effectiveness test cases as it works to expand and evolve its consensus-driven testing model.

External Links September 6, 2022
PoE Technical FAQ

PoE FAQ's

External Links September 23, 2014
Power over Ethernet (PoE) Certification Process Grace Silha

The UNH-IOL acts as the 3rd Party Test Lab for the Ethernet Alliance PoE Certification Program. This Program works to identify PoE Powered Devices (PDs) and Power Sourcing Equipment (PSEs) that are based on IEEE 802.3 PoE specifications and have passed the Ethernet Alliance PoE Test Plan. Learn more about the process in this step by step graphic.

Tutorials February 28, 2022
PPP Design, Implementation, and Debugging, Second Edition James Carlson

From the back cover: "PPP Design, Implementation, and Debugging, Second Edition, is a complete and convenient resrouce for netowrk system designers and administrators. This book contains everything you need to know to work with the Point-to-Point Protocol (PPP), one of the most important Internet protocols in use today. Inside you'll find clear explanations of the underlying concepts, practical implementation information, and valuable debugging techniques to keep your PPP connections running smoothly, efficiently, and uninterrupted."

Recommended Textbooks June 26, 2012
Presentation on the 10GEC Bob Noseworthy

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

Tutorials November 5, 2002
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.

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

Terms used when discussing PTP

White Papers June 28, 2012
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.

Theses December 7, 2000
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.

Theses December 13, 2004
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.

External Links October 22, 2014
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.

White Papers November 4, 2002
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.

Theses April 23, 2002
Routing OSPFv2 Guide UNH-IOL

This document describes the OSPF Protocol.

Tutorials July 21, 2008
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.

White Papers September 18, 2014
RVU Alliance Testing Robert Noseworthy

The UNH-IOL is an approved RVU Alliance Independent Certification Vendor (ICV). With a UNH-IOL Home Networking (HNC) membership companies are able to certify an unlimited amount of devices in a year. For companies looking to obtain RVU Alliance certification for only a few devices a year, the HNC offers pay-as-you-go RVU test services. Please note, these test services are available to RVU Alliance™ members only.

White Papers April 17, 2015
SAS_Clause_5_Considerations IOL

Topics of transmission Speeds and Unit Intervals, OOB Construction, and Differential Signaling.

Tutorials September 23, 2014
SAS_Clause_6 IOL

Discussing OOB State Machine, speed negotiation, 8b10B Encoding and Synchronization State Machine.

Tutorials September 23, 2014
SAS_Clause_7 IOL

Presenting Clause 7 with a primitive Overview, Primitive Types and definitions, and open Connection Handshake.

Tutorials September 23, 2014
SAS_Clause_9 IOL

Presenting the topics of Transport Layer Protocols: SSP, SMP and STP.

Tutorials September 23, 2014
SAS_Testing IOL

Overview of the physical Layer Test Suites and Equipment, Protocol test suites and equipment and Interop testing.

Tutorials September 23, 2014