Hawari, Mohammed; Clausen, Thomas OP4T: Bringing Advanced Network Packet Timestamping into the Field Inproceedings 2021 International Conference on Information Networking (ICOIN), pp. 137-142, 2021. Abstract | Links | BibTeX @inproceedings{Hawari2021,
title = {OP4T: Bringing Advanced Network Packet Timestamping into the Field},
author = {Mohammed Hawari and Thomas Clausen},
url = {https://www.thomasclausen.net/wp-content/uploads/2021/03/paper.pdf},
doi = {10.1109/ICOIN50884.2021.9333927},
year = {2021},
date = {2021-01-13},
booktitle = {2021 International Conference on Information Networking (ICOIN)},
pages = {137-142},
abstract = {Because it is very bursty, the microsecond-scale temporal behaviour of network traffic in data-centres is chal- lenging to measure and understand. To bring observability into data-centre networks, this paper introduces the Open Platform for Programmable Precise Packet Timestamping (OP4T), a hardware architecture, targeting Field-Programmable Gateway Arrays (FPGAs), integrated into data-centre servers as a Smart Network Interface Card (SmartNIC), and flexible enough to enable advanced latency diagnosis.
In this paper, OP4T is specified, and an open-source im- plementation of that architecture is proposed, targeting the NetFPGA SUME prototyping board. By leveraging the P4 programming language, and partial reconfiguration, that open- source implementation is experimentally shown to enable in-band, precise packet timestamping, without sacrificing the achievable throughput. As an illustration, OP4T is shown to be usable to measure fine-grained properties of a software packet forwarder, e.g., packet batching.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Because it is very bursty, the microsecond-scale temporal behaviour of network traffic in data-centres is chal- lenging to measure and understand. To bring observability into data-centre networks, this paper introduces the Open Platform for Programmable Precise Packet Timestamping (OP4T), a hardware architecture, targeting Field-Programmable Gateway Arrays (FPGAs), integrated into data-centre servers as a Smart Network Interface Card (SmartNIC), and flexible enough to enable advanced latency diagnosis.
In this paper, OP4T is specified, and an open-source im- plementation of that architecture is proposed, targeting the NetFPGA SUME prototyping board. By leveraging the P4 programming language, and partial reconfiguration, that open- source implementation is experimentally shown to enable in-band, precise packet timestamping, without sacrificing the achievable throughput. As an illustration, OP4T is shown to be usable to measure fine-grained properties of a software packet forwarder, e.g., packet batching. |
Hawari, Mohammed; Cordero, Juan Antonio; Clausen, Thomas High-Accuracy Packet Pacing on Commodity Servers for Constant-Rate Flows Journal Article IEEE/ACM Transactions on Networking, pp. 1-15, 2020, ISSN: 1558-2566. Abstract | Links | BibTeX @article{9130915,
title = {High-Accuracy Packet Pacing on Commodity Servers for Constant-Rate Flows},
author = {Mohammed Hawari and Juan Antonio Cordero and Thomas Clausen},
url = {https://www.thomasclausen.net/wp-content/uploads/2020/08/2020-IEEE-TNET-High-Accuracy-Packet-Pacing-on-Commodity-Servers-for-Constant-Rate-Flows.pdf},
doi = {10.1109/TNET.2020.3001672},
issn = {1558-2566},
year = {2020},
date = {2020-01-01},
journal = {IEEE/ACM Transactions on Networking},
pages = {1-15},
abstract = {This addresses the problem of high-quality packet pacing for constant-rate packet consumption systems, with strict buffering limitations. A mostly-software pacing architecture is developed, which has minimal hardware requirements, satisfied by commodity servers - rendering the proposed solution easily deployable in existing (data-centre) infrastructures. Two algorithms (free-running and frequency-controlled pacing, for explicitly and implicitly indicated target rates, respectively) are specified, and formally analysed. The proposed solution, including both algorithms, is implemented, and is tested on real hardware and under real conditions. The performance of these implementations is experimentally evaluated and compared to existing mechanisms, available in general-purpose hardware. Results of both exhaustive experiments, and of an analytical modeling, indicate that the proposed approach is able to perform low-jitter packet pacing on commodity hardware, being thus suitable for constant rate transmission and consumption in media production scenarios.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This addresses the problem of high-quality packet pacing for constant-rate packet consumption systems, with strict buffering limitations. A mostly-software pacing architecture is developed, which has minimal hardware requirements, satisfied by commodity servers - rendering the proposed solution easily deployable in existing (data-centre) infrastructures. Two algorithms (free-running and frequency-controlled pacing, for explicitly and implicitly indicated target rates, respectively) are specified, and formally analysed. The proposed solution, including both algorithms, is implemented, and is tested on real hardware and under real conditions. The performance of these implementations is experimentally evaluated and compared to existing mechanisms, available in general-purpose hardware. Results of both exhaustive experiments, and of an analytical modeling, indicate that the proposed approach is able to perform low-jitter packet pacing on commodity hardware, being thus suitable for constant rate transmission and consumption in media production scenarios. |
Toussaint, Arthur; Hawari, Mohammed; Clausen, Thomas Chasing Linux Jitter Sources for Uncompressed Video Incollection In Proceedings of the 1st Workshop on High-Precision Networks Operations and Control (HiPNet 2018) ad the IEEE 14th International Conference on Network and Service Management (CNSM), 2018. Abstract | Links | BibTeX @incollection{Toussaint2018,
title = {Chasing Linux Jitter Sources for Uncompressed Video},
author = {Arthur Toussaint and Mohammed Hawari and Thomas Clausen},
url = {https://www.thomasclausen.net/wp-content/uploads/2019/11/CNSM-HipNet-Toussaint-et.-al.-Chasing-Linux-Jutter-Sources-for-Uncompressed-Video.pdf},
year = {2018},
date = {2018-11-01},
booktitle = {In Proceedings of the 1st Workshop on High-Precision Networks Operations and Control (HiPNet 2018) ad the IEEE 14th International Conference on Network and Service Management (CNSM)},
abstract = {Beyond the transport of uncompressed video over IP networks, defined in standards such as ST2022-6, the ability to build software-based Video Processing Functions (VPF) on commodity hardware and using general purpose Operating Systems is the next logical step in the evolution of the media industry towards an “all-IP” world. In that context, understand- ing the jitter induced on an ST2022-6 stream by a commodity platform is essential. This paper describes a general methodology to enumerate jitter sources on commodity platforms and to quantify their relative contribution to the overall system jitter. The methodology is applied to the Linux kernel, producing a classification of the different sources of jitter, and a quantification of their impact.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Beyond the transport of uncompressed video over IP networks, defined in standards such as ST2022-6, the ability to build software-based Video Processing Functions (VPF) on commodity hardware and using general purpose Operating Systems is the next logical step in the evolution of the media industry towards an “all-IP” world. In that context, understand- ing the jitter induced on an ST2022-6 stream by a commodity platform is essential. This paper describes a general methodology to enumerate jitter sources on commodity platforms and to quantify their relative contribution to the overall system jitter. The methodology is applied to the Linux kernel, producing a classification of the different sources of jitter, and a quantification of their impact. |
