Knowledge Base

Title Authors Last Update Category
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.

July 2, 2013 Tutorials
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.

February 18, 2013 White Papers
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.

January 18, 2013 White Papers
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.

January 2, 2013 External Links
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.

January 2, 2013 External Links
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.

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

N/A

December 13, 2012 Tutorials
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.

December 7, 2012 Theses
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.

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

used at UNH-IOL for training and discussion

December 6, 2012 White Papers