Knowledge Base

Title Authors Category Updated
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
How to Make Cable Plants Jon Beck and Austin Boech

An overview of how the UNH-IOL Fast Ethernet and Gigabit Ethernet Consortia create the cable plants that are used during InterOperability testing for 1000BASE-T devices.

Tutorials December 10, 2004
OSRM Test Event 2004 Henry He, Chris Volpe, Takumi Ohba, Kaori Shimizu, Yumiko Kawashima, and Tom DiMicelli

The second UNH-IOL OSRM test event included seven different companies and was designed in collaboration with Nippon Telegraph and Telephone Corp. (NTT) and the participants to validate and prove GMPLS functionality in a multi-vendor network. This collaboration generated an exceptionally realistic and demanding test suite in line with service providers\' operational demands, rather than simple conformance or interoperability scenarios.

White Papers September 27, 2004
Moonv6 PhaseII Whitepaper UNH-IOL

Phase II of the Moonv6 project established the largest native IPv6 network in the world. The second phase of the project was able to demonstrate high speed links, advanced routing functionality, firewalls, QoS, and other key features. More than two dozen organizations participated in Phase II, and testing was facilitated by engineers from nine separate sites.

White Papers July 5, 2004
Super Demo 2004 MFA and MSF

SuperDemo 2004 was the product of a partnering of the Multiservice Switching Forum (MSF) with the MPLS & FR alliance. Eleven companies participated in expanded testing including advanced service provider applications. The collaboration of the MSF and the MFA took the meaning of success to another level in the industry. The Multi-Vendor MPLS infrastructure was constructed for stability and reliability. The Demonstration of VoIP services across this network clearly conveyed a feeling of resilience.

White Papers June 28, 2004
DSL Crosstalk Simulation and Calibration Tim Clark (UNH-IOL)

The performance of DSL transceivers can be impaired by interference from other transceivers operating over wires in the same binder group. It is therefore important to test DSL transceivers in the presence of crosstalk, which can be simulated in a programming environment such as MATLAB. The simulated crosstalk can then be exported to an arbitrary waveform generator (AWG) for injection onto the line through a high-impedance noise injection circuit. This document describes a method of crosstalk simulation and calibration whereby white gaussian noise (WGN) is passed through a frequency-domain filter that gives the noise the spectral characteristics of crosstalk. The crosstalk is calibrated by measuring its power with a vector signal analyzer (VSA) and adjusting the output level on the AWG to achieve the desired noise power. By using MATLAB to estimate the simulated crosstalk power in the same manner as the VSA, the calibration can be performed in MATLAB without taking actual measurements.

White Papers May 11, 2004
Design and Implementation of iFCP Claire Kraft

iFCP is one form of storage over TCP/IP that allows hosts and Fibre Channel storage devices to communicate directly. It is an encapsulation protocol that dictates the means by which Fibre Channel frames become the payload in an iFCP message. In addition, iFCP introduces a few new types of messages for purposes of control. This thesis is comprised of the design and implementation of iFCP end devices. The initiator has been implemented as a software module that behaves like a Fibre Channel Host Bus Adapter with an attached encapsulator. The target has been implemented as a stand-alone software program that acts both as an encapsulator and as a Fibre Channel switch that is attached through a generator to a Fibre Channel disk.

Theses May 1, 2004
EFM OAM Tutorial Kevin Daines

Tutorial generated by the IEEE EFM task force.

Tutorials March 1, 2004
MPLS World Congress 2004 MFA and EANTC

This interoperability evaluation focused on the transport of differentiated services on a multi-vendor MPLS backbone supporting MPLS traffic engineering. The MPLS World Congress 2004 demonstrated differentiated services over MPLS and MPLS traffic engineering. Multi-vendor MPLS/BGP VPN\'s and Layer 2 Ethernet VPN\'s (Martini and VPLS) were configured to prove that services were traffic engineering-enabled and could process differentiated services.

White Papers February 23, 2004
OSRM January 2004 Chris Volpe, Ichiro Inoue, Kaori Shimizu, Yumiko Kawashima, and Tom Dimicelli

The first OSRM event, held at the University of New Hampshire InterOperability Laboratory (UNH-IOL), provided an aggressive carrier-class environment for GMPLS testing including several GMPLS interworking scenarios that had not been achieved in previous multi-vendor test settings. The testing, conducted by the UNH-IOL OSRM test group, involved a variety of test cases that focused on stability testing, control channel fault handling and data channel failure recovery.

White Papers January 26, 2004
Clause 24: 100BASE-X Physical Coding Sublayer (PCS)

An overview of the 100BASE-TX PCS created by the UNH-IOL.

Tutorials January 1, 2004
Clause 37: Auto-Negotiation David Estes

An introduction to the Clause 37 Auto-Negotiation Process.

Tutorials January 1, 2004
Clause 40: 1000BASE-T Physical Medium Attachment (PMA) Sublayer

1000BASE-T PMA overview (location in the OSI stack, interface with PCS, interface with Auto-Negotiation, PAM-5 Encoding Scheme, PMA Sublayers Functionality and Functions, and PMA Electrical Specifications).

Tutorials January 1, 2004
Clause 28 & 40 Auto-Negotiation: An Introduction to the Auto-Negotiation process Jeff Lapak

A brief introduction to auto-negotiation created by the UNH-IOL.

Tutorials January 1, 2004
Moonv6 PhaseI Whitepaper UNH-IOL

Phase I of Moonv6 demonstrated that current IPv6 networking technology is stable, resilient and ready for integration with today\'s Internet. The event was attended by more than thirty different organizations and confirmed several stable and interoperable implementations of IPv6, and proved that IPv6 is ready to be deployed on a global scale. Specific aspects of IPv6 included common network applications, base specifications, transition mechanisms, routing protocols, security and mobility.

White Papers November 3, 2003
US Frequency Allocation Chart US Dept. of Commerce

The United States Commerce Department's National Telecommunications and Information Administration (NTIA) spectrum chart, dated October 2003, depicts the radio frequency spectrum allocations to radio services operated within the United States.

External Links October 1, 2003
SuperDemo 2003 MFA

SuperDemo 2003 was the worlds most advanced and comprehensive live test of multiple MPLS services operating concurrently across a multi-vendor MPLS network. The MPLS/FR Alliance SuperDemo included 14 different companies showcasing MPLS services and features such as VPLS, ATM/FR/Ethernet over MPLS, BGP MPLS VPNs and Fast re-route.

White Papers June 9, 2003
Presentation on the 10GEC Bob Noseworthy

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

Tutorials November 5, 2002
An ITU-T G.994.1 Protocol Analysis Tool For ADSL Matthew Langlois (UNH-IOL), Dr. Michael Carter, Dr. William Lenharth, and Scott Valcourt

One of the most commonly deployed DSL variants is ADSL. Despite this fact, deployment of new robust and reliable ADSL services is increasingly difficult due, in part, to the physical limitations of the copper telephone system infrastructure, and also in part to the lack of useful ADSL network debugging tools. ADSL service providers and technicians currently lack a device capable of decoding physical layer signaling and displaying actual physical layer parameters and statistics associated with a live ADSL connection, independent of the end stations. Similar devices used in other network technologies are often referred to as protocol analyzers. The intent of this paper is to illustrate how Matlab [1], in conjunction with a DSP or a PC, can be used to create an effective ADSL handshaking protocol analyzer based on ITU-T G.994.1 (G.hs) [2]. G.hs conformance is critical in establishing a successful ITU-T G.992.1 (G.dmt) [3] based ADSL connection.

White Papers November 4, 2002
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
VDSL MCM Simulation Tim Clark (UNH-IOL)

An introduction to MCM for VDSL.

Tutorials October 2, 2002
VDSL Modulation Schemes: MCM vs. SCM Tim Clark (UNH-IOL)

This presentation provides an overview and comparison of the two proposed VDSL modulation schemes.

Tutorials October 2, 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
A G.hs Handshaking Protocol Analyzer For ADSL Matthew Langlois

A protocol analyzer is a device that non-intrusively monitors bi-directional communications on a link, demodulates the physical layer signals, and captures the raw binary data for subsequent state and timing analysis. There are no commercial products currently available that perform this function for ADSL link initialization procedures. In this project, a MATLAB application was developed that enables capture (via a digital sampling oscilloscope) and protocol analysis of the first segment, known as handshaking, of the ADSL link initialization procedure. The protocols of interest are ITU-T G.994.1 (G.hs), which defines the activation and handshaking procedures used by complaint ADSL equipment, and ITU-T G.992.1 (G.dmt), which defines the physical layer requirements of ADSL equipment utilizing the Discrete Multi-Tone (DMT) line code.

Theses December 14, 2001
10 Gigabit Ethernet Clause 48 Tutorial Vinod Venkatavaradan

Clause 48 overview

Tutorials December 12, 2001