Knowledge Base

Title Authors Category Updated
Comparison of Environments on 802.11 Throughput Performance Diana Lewis, Justin Rebe, Jeremy deVries

The chaotic nature of the radio frequency medium of 802.11 wireless networks makes it problematic to obtain accurate and precise repetition of performance tests and measurements. Environmental variables that deeply influence link performance must be addressed before throughput testing can be accurately measured across various devices. An RF shielded room with anechoic foam provides the most ideal environment for throughput tests compared to either an RF shielded room without foam or an open air laboratory. Location within the RF shielded room with anechoic foam was shown to have a negligible effect on performance, but using an RF absorbing rubber mat under a device was shown to reduce reflections, producing an optimal environment for throughput testing.

White Papers September 18, 2014
IEEE 802.11 TGe - QoS Enhancements (D6.0) Chris Polanec

Overview of Quality of Service (QoS) Enhancements for the MAC based on TGe draft 6.0.

Tutorials September 18, 2014
Tutorial: The Time-Synchronization Standard from the AVB/TSN suite IEEE STd 802.1AS-2011 and following Kevin Stanton, Intel

This presentation provides an overview of clock and time synchronization across heterogeneous networks using the published standards:
- IEEE Std 802.1AS(TM)-2011 and
- IEEE Std 802.11(TM)-2012 Timing Measurement

With special focus on wireless / 802.11 links

External Links July 17, 2014
An Efficient Method for Stream Semantics over RDMA P. MacArthur and R. Russell

Most network applications today are written to use TCP/IP via sockets. Remote Direct Memory Access (RDMA) is gaining popularity because its zero-copy, kernel-bypass features provide a high throughput, low latency reliable transport. Unlike TCP, which is a stream-oriented protocol, RDMA is a message-oriented protocol, and the OFA verbs library for writing RDMA application programs is more complex than the TCP sockets interface. UNH EXS is one of several libraries designed to give applications more convenient, high-level access to RDMA features. Recent work has shown that RDMA is viable both in the data center and over distance.

One potential bottleneck in libraries that use RDMA is the requirement to wait for message advertisements in order to send large zero-copy messages. By sending messages first to an internal, hidden buffer and copying the message later, latency can be reduced at the expense of higher CPU usage at the receiver. This paper presents a communication algorithm that has been implemented in the UNH EXS stream-oriented mode to allow dynamic switching between sending transfers directly to user memory and sending transfers indirectly via an internal, hidden buffer depending on the state of the sender and receiver. Based on preliminary results, we see that this algorithm performs well under a variety of application requirements.

White Papers May 21, 2014
Epoch Converter

Epoch & Unix Timestamp Conversion Tools

External Links October 7, 2013
10Gig Link Fault Signaling Eric Lynskey

Short overview of how 10Gig link fault signaling works.

Tutorials September 5, 2013
FQTSS Overview William Gravelle

FQTSS is defined in the IEEE standard 801.Q Clause 34; Forwarding and Queuing Enhancements for Time-Sensitive Streams. The term FQTSS is used to describe a set of tools which are used to forward and queue time-sensitive streams. Since AVB frames cannot be dropped, there must be a mechanism in place to forward AVB frames quickly and efficiently. This is where FQTSS (aka Qav) comes into play. This paper goes into the components that make up FQTSS.

White Papers July 16, 2013
Mellanox IB DDR Auto-negotiation Specification 1.0

The specification for the Mellanox DDR Proprietary Auto-negotiation protocol.

White Papers July 11, 2013
Neighbor Discovery State Machine for the Reachability State Andrew Gadzik, Thomas Peterson, Chris Cavanaugh

This state machine flow chart covers a summary of the rules specified in RFC 4861 Sections 7.2 and 7.3.

Tutorials July 2, 2013
Testing TRILL (TRansparent Interconnect for Lots of Links) Christina Dube

The University of New Hampshire InterOperability Laboratory (UNH-IOL) hosted its second TRansparent Interconnect of Lots of Links (TRILL) Interoperability Test Event the week of November 26 – December 1, 2012 at its 32,000+ square-foot facility in Durham, New Hampshire. The test event brought together implementers of TRILL as well as test equipment manufacturers that support TRILL. The purpose of the test event was to gain a perspective on the current status of TRILL implementation and interoperability. Participants included Hewlett-Packard Networking, Extreme Networks, Ixia and Spirent Communications.

White Papers February 18, 2013
A Performance Study to Guide RDMA Programming Decisions Patrick MacArthur and Dr. Robert Russell

This paper describes a performance study of Remote Direct Memory Access (RDMA) programming techniques. Its goal is to use these results as a guide for making "best practice" RDMA programming decisions. Infiniband RDMA is widely used in scientific high performance computing (HPC) clusters as a low-latency, high-bandwidth, reliable interconnect accessed via MPI. Recently it is gaining adherents outside scientific HPC as high-speed clusters appear in other application areas for which MPI is not suitable. RDMA enables user applications to move data
directly between virtual memory on different nodes without operating system intervention, so there is a need to know how to incorporate RDMA access into high-level programs. But RDMA offers more options to a programmer than traditional sockets programming, and it is not always obvious what the performance tradeoffs of these options might be. This study is intended to provide some answers.

White Papers January 18, 2013
UNH-IOL, OPEN Alliance target 100 Mbps Ethernet for cars

The University of New Hampshire InterOperability Laboratory (UNH-IOL) in partnership with the OPEN Alliance Special Interest Group (SIG) on Monday unveiled the Automotive Ethernet Consortium.

This consortium is charged with testing and promoting BroadR-Reach, a 100 Mbps Ethernet connectivity specification for the automotive industry. UNH-IOL will be the first lab to conduct tests on the emerging standard.

External Links January 2, 2013
OPEN Alliance

The OPEN (One-Pair Ether-Net) Alliance is designed to encourage wide scale adoption of Ethernet-based, single pair unshielded networks as the standard in automotive applications. The jointly developed OPEN Alliance SIG (Special Interest Group) will address industry requirements for improving in-vehicle safety, comfort, and infotainment, while significantly reducing network complexity and cabling costs.

External Links January 2, 2013
A General-Purpose API for iWARP and InfiniBand Dr. Robert Russell

Remote Direct Memory Access (RDMA) allows data to be transferred over a network directly from the memory of one computer to the memory of another computer without CPU intervention. There are two major types of RDMA hardware on the market today: InfiniBand, and RDMA over IP, also known as iWARP. This hardware is supported by open software that was developed by the OpenFabrics Alliance (OFA) and that is known as
the OpenFabrics Enterprise Distribution (OFED) stack. This stack provides a common interface to both types of RDMA hardware, but does not itself provide a general-purpose API that would be convenient to most network programmers. Rather, it supplies the tools by which such APIs can be constructed.
The Extended Sockets API (ES-API) is a specification published by the Open Group that defines extensions to the traditional socket API which include two major new features necessary to exploit the advantages of RDMA hardware and the OFED stack: asynchronous I/O and memory registration.

The UNH-EXS interface is a multi-threaded implementation of the ES-API plus additional extensions, which enables programmers to utilize RDMA hardware via the OFED stack in a convenient, relatively familiar manner. The UNH-EXS interface is implemented entirely in user space on the Linux operating system. This provides easy porting, modification and adoption of UNH-EXS, since it requires no changes to existing Linux kernels. We present results on the performance of some benchmark applications using the UNH-EXS interface on both iWARP and InfiniBand hardware.

White Papers December 13, 2012
10 Gigabit Ethernet Clause 50 Tutorial Andy Baldman

N/A

Tutorials December 13, 2012
The Extended Sockets Interface for Accessing RDMA Hardware Dr. Robert Russell

The Extended Sockets API (ES-API) is a specification published by the OpenGroup that defines extensions to the
traditional socket API which include two major new features: asynchronous I/O, and memory registration. These
features enable programmers to take advantage of today's
multi-core processors and Remote Direct Memory Access
(RDMA) network hardware, such as iWARP and InfiniBand interfaces, in a convenient yet efficient manner.
This paper describes the UNH EXS interface, an implementation of the ES-API that provides additional API
facilities which enable a programmer to utilize RDMA network hardware while selectively choosing those features of
this interface that are most germane to the particular application. In addition, the UNH EXS interface is implemented
entirely in user space on the Linux operating system. This
provides easy porting, modification and adoption of UNH EXS, since it requires no changes to existing Linux kernels.
Preliminary results demonstrate that applications based on
EXS can achieve high bandwidth utilization and low CPU
overhead.

White Papers December 7, 2012
Fairness in a data center Mikkel Hagen

Existing data centers utilize several networking technologies in order to handle the performance requirements of different workloads. Maintaining diverse networking technologies increases complexity and is not cost effective. This results in the current trend to converge all traffic into a single networking fabric. Ethernet is both cost-effective and ubiquitous, and as such it has been chosen as the technology of choice for the converged fabric. However, traditional Ethernet does not satisfy the needs of all traffic workloads, for the most part, due to its lossy nature and, therefore, has to be enhanced to allow for full convergence. The resulting technology, Data Center Bridging (DCB), is a new set of standards defined by the IEEE to make Ethernet lossless even in the presence of congestion. As with any new networking technology, it is critical to analyze how the different protocols within DCB interact with each other as well as how each protocol interacts with existing technologies in other layers of the protocol stack.

This dissertation presents two novel schemes that address critical issues in DCB networks: fairness with respect to packet lengths and fairness with respect to flow control and bandwidth utilization. The Deficit Round Robin with Adaptive Weight Control (DRR-AWC) algorithm actively monitors the incoming streams and adjusts the scheduling weights of the outbound port. The algorithm was implemented on a real DCB switch and shown to increase fairness for traffic consisting of mixed-length packets. Targeted Priority-based Flow Control (TPFC) provides a hop-by-hop flow control mechanism that restricts the flow of aggressor streams while allowing victim streams to continue unimpeded. Two variants of the targeting mechanism within TPFC are presented and their performance evaluated through simulation.

Theses December 7, 2012
Space-Time Diagrams (PPT) Jeff Laird

used at UNH-IOL for training and discussion

White Papers December 6, 2012
Advantages and Testing Considerations of a Converged DCB Network Presentation Peter J. Scruton

Peter participated in the 2012 Ethernet Technology Summit in San Jose, California as a panelist in one of the Sessions. The Session focus was on the Continuing Role of Ethernet in Storage.

External Links December 4, 2012
Comparison of DCBX Versions Daniel Shea

A comparison of the baseline versus the IEEE standard versions of Data Center Bridging Capabilities Exchange.

Tutorials September 11, 2012
Testing Home Routers for World IPv6 Launch Timothy Winters

The University of New Hampshire InterOperability Laboratory (UNH-IOL) hosted its fourth IPv6 Customer Edge (CE) Router Interoperability Test Event the week of April 16 - April 20, 2012 at its 32,000+ square-foot facility in Durham, New Hampshire. The test event brought together both users and suppliers of CE routers, also known as home router equipment. The purpose of the test event was to gain a perspective on the current status of IPv6 interoperability against the Internet Engineering Task Force (IETF) Basic Requirements for IPv6 Customer Edge Routers and support the Internet Society (ISOC) World IPv6 Launch. The eight participating vendor companies tested a total of ten distinct home router implementations throughout the week using publicly routable IPv6 addresses. Participants included Broadcom, CHT-TL IPv6 Testing Lab, D-Link, NDM Systems, Motorola Mobility LLC, Netgear, Time Warner and ZyXEL.

Observations discussed in this paper include:
* DHCP Solicits Frequency
* Renumbering
* No Default Route
* Forwarding before Address Acquisition
* DHCPv6 IA_PD & IA_NA Interactions

White Papers August 31, 2012
IPv6 Essentials Silvia Hagen

IPv6 Essentials, Second Edition provides a succinct, in-depth tour of all the new features and functions in IPv6. It guides you through everything you need to know to get started, including how to configure IPv6 on hosts and routers and which applications currently support IPv6. The new IPv6 protocols offers extended address space, scalability, improved support for security, real-time traffic support, and auto-configuration so that even a novice user can connect a machine to the Internet. Aimed at system and network administrators, engineers, network designers, and IT managers, this book will help you understand, plan for, design, and integrate IPv6 into your current IPv4 infrastructure.

Recommended Textbooks July 10, 2012
Demystifying the IPsec Puzzle Sheila Frankel

Now that the Internet has blossomed into the "Information Superhighway" with its traffic and drivers becoming increasingly diverse, security has emerged as a primary concern. This book offers the reader a global, integrated approach to providing internet security at the network layer. The author gives a detailed presentation of the revolutionary IPsec technology used today to create Virtual Private Networks and, in the near future, to protect the infrastructure of the Internet itself. The book addresses IPsec's major aspects and components to help the reader evaluate and compare features of different implementations. It provides a detailed understanding of this cutting-edge technology from the inside, which enables the reader to more effectively troubleshoot problems with specific products. Based on standards documents, discussion list archives, and practitioners' lore, this resource collects all the current knowledge of IPsec and describes it in a literate, clear manner.

Recommended Textbooks July 10, 2012
40 Gigabit Ethernet and 100 Gigabit Ethernet Technology Overview John D’Ambrosia, Force10 Networks, David Law, 3COM, and Mark Nowell, Cisco Systems

Overview of 40 and 100 Gigabit Ethernet Technology; provided by the Ethernet Alliance, June 2010

External Links July 5, 2012
10BASE-T Medium Attachment Unit

An overview of the 10BASE-T Medium Attachment Unit.

Tutorials July 5, 2012