Rolf Clauberg - Academia.edu (original) (raw)

Papers by Rolf Clauberg

Research paper thumbnail of STM-1 to STM-64 SDH/SONET framer with data multiplexing from a series of configurable I/O ports

STM-1 to STM-64 SDH/SONET framer with data multiplexing from a series of configurable I/O ports

Research paper thumbnail of Method for investigating surfaces at nanometer and picosecond resolution and laser-sampled scanning tunneling microscope for performing said method

Method for investigating surfaces at nanometer and picosecond resolution and laser-sampled scanning tunneling microscope for performing said method

Research paper thumbnail of Unbiased QCN for Scalable Server-Fabrics

Unbiased QCN for Scalable Server-Fabrics

IEEE Micro, 2015

Research paper thumbnail of Converged Enhanced Ethernet Network

Converged Enhanced Ethernet Network

Research paper thumbnail of Arbitration of many thousand flows at 100G and beyond

Arbitration of many thousand flows at 100G and beyond

Proceedings of the 2013 Interconnection Network Architecture: On-Chip, Multi-Chip on - IMA-OCMC '13, 2013

ABSTRACT Network devices supporting above-100G links are needed today in order to scale communica... more ABSTRACT Network devices supporting above-100G links are needed today in order to scale communication bandwidth along with the processing capabilities of computing nodes in data centers and warehouse computers. In this paper, we propose a light-weight, fair scheduler for such ultra high-speed links, and an arbitrarily large number of requestors. We show that, in practice, our first algorithm, as well its predecessor, DRR, may result in bursty service even in the common case, where flow weights are approximately equal, and we identify applications where this can damage performance. Our second contribution is an enhancement that improves short-term fairness to deliver very smooth service when flow weights are approximately equal, whilst allocating bandwidth in a weighted fair manner.

Research paper thumbnail of 4.4 Energy-efficient microserver based on a 12-core 1.8GHz 188K-CoreMark 28nm bulk CMOS 64b SoC for big-data applications with 159GB/S/L memory bandwidth system density

4.4 Energy-efficient microserver based on a 12-core 1.8GHz 188K-CoreMark 28nm bulk CMOS 64b SoC for big-data applications with 159GB/S/L memory bandwidth system density

2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers, 2015

Research paper thumbnail of Occupancy Sampling for Terabit CEE Switches

Occupancy Sampling for Terabit CEE Switches

2012 IEEE 20th Annual Symposium on High-Performance Interconnects, 2012

ABSTRACT One consequential feature of Converged Enhanced Ethernet (CEE) is loss lessness, achieve... more ABSTRACT One consequential feature of Converged Enhanced Ethernet (CEE) is loss lessness, achieved through L2 Priority Flow Control (PFC) and Quantized Congestion Notification (QCN). We focus on QCN and its effectiveness in identifying congestive flows in input-buffered CEE switches. QCN assumes an idealized, output-queued switch, however, as future switches scale to higher port counts and link speeds, purely output-queued or shared-memory architectures lead to excessive memory bandwidth requirements, moreover, PFC typically requires dedicated buffers per input. Our objective is to complement PFC's coarse per-port/priority granularity with QCN's per-flow control. By detecting buffer overload early, QCN can drastically reduce PFC's side effects. We install QCN congestion points (CPs) at input buffers with virtual output queues and demonstrate that arrival-based marking cannot correctly discriminate between culprits and victims. Our main contribution is occupancy sampling (QCN-OS), a novel, QCN-compatible marking scheme. We focus on random occupancy sampling, a practical method not requiring any per-flow state. For CPs with arbitrarily scheduled buffers, QCN-OSis shown to correctly identify congestive flows, improving buffer utilization, switch efficiency, and fairness.

Research paper thumbnail of Beam properties of AlGaAs power lasers with high-quality etched mirrors

IEEE Photonics Technology Letters, 2000

High-quality etched mirrors for AIGaAs/GaAs power lasers for applications in optical storage have... more High-quality etched mirrors for AIGaAs/GaAs power lasers for applications in optical storage have been fabricated by chemically assisted ion-beam etching. In order to ensure flat mirror facets of the ridge-waveguide lasers, a flared-waveguide end section is employed. This results in a very slight mirror roughness of -20 nm across the beam cross section, and yields excellent beam properties allowing diffraction-limited focusing up to 50 mW output power.

Research paper thumbnail of Design methodology for a large communication chip

Design methodology for a large communication chip

IEEE Design & Test of Computers, 2000

ABSTRACT

Research paper thumbnail of Contactless, high-speed waveform measurements on gallium arsenide ICs

Contactless, high-speed waveform measurements on gallium arsenide ICs

IEEE Design & Test of Computers, 2000

A setup for photoemission testing, which compares favorably with results from electron-beam testi... more A setup for photoemission testing, which compares favorably with results from electron-beam testing, particularly in terms of measurement time, is presented. The photoemission sampling system described has a unique detector design and a viewer for the added convenience of the equipment operator. performance results when this technique is used to measure delay and rise times on integrated gallium arsenide MESFET

Research paper thumbnail of Tandem queue weighted fair smooth scheduling

Tandem queue weighted fair smooth scheduling

Design Automation for Embedded Systems, 2014

ABSTRACT Network devices supporting 100G links are in demand to meet the communication requiremen... more ABSTRACT Network devices supporting 100G links are in demand to meet the communication requirements of computing nodes in datacenters and warehouse computers. In this paper, we propose TQ and TQ-Smooth, two light-weight, fair schedulers that accommodate an arbitrarily large number of requestors and are suitable for ultra high-speed links. We show that our first algorithm, TQ, as well its predecessor, DRR, may result in bursty service even in the common case where flow weights are approximately equal, and we find that this can damage the performance of buffer-credit allocation schemes. Our second algorithm, TQ-Smooth, improves short-term fairness to deliver very smooth service when flow weights are approximately equal, while allocating bandwidth in a weighted fair manner. In many practical situations, a scheduler is asked to allocate resources in fixed-size chunks (e.g. buffer units), whose size may exceed that of (small) network packets. In such cases, byte-level fairness will typically be compromised when small-packet flows compete with large-packet ones. We describe and evaluate a scheme that dynamically adjusts the service rates of request/grant buffer reservation to achieve byte-level fairness based on received packet sizes.

Research paper thumbnail of ICCCN 2004 Technical Program Committee Members

ICCCN 2004 Technical Program Committee Members

Page 1. ICCCN 2004 Technical Program Committee Members Chin-Tser Huang University of South Caroli... more Page 1. ICCCN 2004 Technical Program Committee Members Chin-Tser Huang University of South Carolina Stephen Bush GE Global Research Srihari Varada Transwitch Corporation Yang Xiao The University of Memphis Jingyuan Zhang The University ofAlabama Sunghyun Choi Seoul National University Zhimo Cao Cisco Systems Derong Liu University of Illinois at Chicago Yuanyuan Yang State University of New York at Stony Brook Ophir Frieder Illinois Institute of Technology Manimaran Govindarasu Iowa State University ...

Research paper thumbnail of Optical waveguide isolation

Optical waveguide isolation

Research paper thumbnail of STM-1 to STM-64 SDH/SONET framer with data multiplexing from a series of configurable I/O ports

STM-1 to STM-64 SDH/SONET framer with data multiplexing from a series of configurable I/O ports

Research paper thumbnail of Method for investigating surfaces at nanometer and picosecond resolution and laser-sampled scanning tunneling microscope for performing said method

Method for investigating surfaces at nanometer and picosecond resolution and laser-sampled scanning tunneling microscope for performing said method

Research paper thumbnail of Unbiased QCN for Scalable Server-Fabrics

Unbiased QCN for Scalable Server-Fabrics

IEEE Micro, 2015

Research paper thumbnail of Converged Enhanced Ethernet Network

Converged Enhanced Ethernet Network

Research paper thumbnail of Arbitration of many thousand flows at 100G and beyond

Arbitration of many thousand flows at 100G and beyond

Proceedings of the 2013 Interconnection Network Architecture: On-Chip, Multi-Chip on - IMA-OCMC '13, 2013

ABSTRACT Network devices supporting above-100G links are needed today in order to scale communica... more ABSTRACT Network devices supporting above-100G links are needed today in order to scale communication bandwidth along with the processing capabilities of computing nodes in data centers and warehouse computers. In this paper, we propose a light-weight, fair scheduler for such ultra high-speed links, and an arbitrarily large number of requestors. We show that, in practice, our first algorithm, as well its predecessor, DRR, may result in bursty service even in the common case, where flow weights are approximately equal, and we identify applications where this can damage performance. Our second contribution is an enhancement that improves short-term fairness to deliver very smooth service when flow weights are approximately equal, whilst allocating bandwidth in a weighted fair manner.

Research paper thumbnail of 4.4 Energy-efficient microserver based on a 12-core 1.8GHz 188K-CoreMark 28nm bulk CMOS 64b SoC for big-data applications with 159GB/S/L memory bandwidth system density

4.4 Energy-efficient microserver based on a 12-core 1.8GHz 188K-CoreMark 28nm bulk CMOS 64b SoC for big-data applications with 159GB/S/L memory bandwidth system density

2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers, 2015

Research paper thumbnail of Occupancy Sampling for Terabit CEE Switches

Occupancy Sampling for Terabit CEE Switches

2012 IEEE 20th Annual Symposium on High-Performance Interconnects, 2012

ABSTRACT One consequential feature of Converged Enhanced Ethernet (CEE) is loss lessness, achieve... more ABSTRACT One consequential feature of Converged Enhanced Ethernet (CEE) is loss lessness, achieved through L2 Priority Flow Control (PFC) and Quantized Congestion Notification (QCN). We focus on QCN and its effectiveness in identifying congestive flows in input-buffered CEE switches. QCN assumes an idealized, output-queued switch, however, as future switches scale to higher port counts and link speeds, purely output-queued or shared-memory architectures lead to excessive memory bandwidth requirements, moreover, PFC typically requires dedicated buffers per input. Our objective is to complement PFC's coarse per-port/priority granularity with QCN's per-flow control. By detecting buffer overload early, QCN can drastically reduce PFC's side effects. We install QCN congestion points (CPs) at input buffers with virtual output queues and demonstrate that arrival-based marking cannot correctly discriminate between culprits and victims. Our main contribution is occupancy sampling (QCN-OS), a novel, QCN-compatible marking scheme. We focus on random occupancy sampling, a practical method not requiring any per-flow state. For CPs with arbitrarily scheduled buffers, QCN-OSis shown to correctly identify congestive flows, improving buffer utilization, switch efficiency, and fairness.

Research paper thumbnail of Beam properties of AlGaAs power lasers with high-quality etched mirrors

IEEE Photonics Technology Letters, 2000

High-quality etched mirrors for AIGaAs/GaAs power lasers for applications in optical storage have... more High-quality etched mirrors for AIGaAs/GaAs power lasers for applications in optical storage have been fabricated by chemically assisted ion-beam etching. In order to ensure flat mirror facets of the ridge-waveguide lasers, a flared-waveguide end section is employed. This results in a very slight mirror roughness of -20 nm across the beam cross section, and yields excellent beam properties allowing diffraction-limited focusing up to 50 mW output power.

Research paper thumbnail of Design methodology for a large communication chip

Design methodology for a large communication chip

IEEE Design & Test of Computers, 2000

ABSTRACT

Research paper thumbnail of Contactless, high-speed waveform measurements on gallium arsenide ICs

Contactless, high-speed waveform measurements on gallium arsenide ICs

IEEE Design & Test of Computers, 2000

A setup for photoemission testing, which compares favorably with results from electron-beam testi... more A setup for photoemission testing, which compares favorably with results from electron-beam testing, particularly in terms of measurement time, is presented. The photoemission sampling system described has a unique detector design and a viewer for the added convenience of the equipment operator. performance results when this technique is used to measure delay and rise times on integrated gallium arsenide MESFET

Research paper thumbnail of Tandem queue weighted fair smooth scheduling

Tandem queue weighted fair smooth scheduling

Design Automation for Embedded Systems, 2014

ABSTRACT Network devices supporting 100G links are in demand to meet the communication requiremen... more ABSTRACT Network devices supporting 100G links are in demand to meet the communication requirements of computing nodes in datacenters and warehouse computers. In this paper, we propose TQ and TQ-Smooth, two light-weight, fair schedulers that accommodate an arbitrarily large number of requestors and are suitable for ultra high-speed links. We show that our first algorithm, TQ, as well its predecessor, DRR, may result in bursty service even in the common case where flow weights are approximately equal, and we find that this can damage the performance of buffer-credit allocation schemes. Our second algorithm, TQ-Smooth, improves short-term fairness to deliver very smooth service when flow weights are approximately equal, while allocating bandwidth in a weighted fair manner. In many practical situations, a scheduler is asked to allocate resources in fixed-size chunks (e.g. buffer units), whose size may exceed that of (small) network packets. In such cases, byte-level fairness will typically be compromised when small-packet flows compete with large-packet ones. We describe and evaluate a scheme that dynamically adjusts the service rates of request/grant buffer reservation to achieve byte-level fairness based on received packet sizes.

Research paper thumbnail of ICCCN 2004 Technical Program Committee Members

ICCCN 2004 Technical Program Committee Members

Page 1. ICCCN 2004 Technical Program Committee Members Chin-Tser Huang University of South Caroli... more Page 1. ICCCN 2004 Technical Program Committee Members Chin-Tser Huang University of South Carolina Stephen Bush GE Global Research Srihari Varada Transwitch Corporation Yang Xiao The University of Memphis Jingyuan Zhang The University ofAlabama Sunghyun Choi Seoul National University Zhimo Cao Cisco Systems Derong Liu University of Illinois at Chicago Yuanyuan Yang State University of New York at Stony Brook Ophir Frieder Illinois Institute of Technology Manimaran Govindarasu Iowa State University ...

Research paper thumbnail of Optical waveguide isolation

Optical waveguide isolation