Dr. Martin Stiemerling
+49 6221 4342-113
NEC Labs in Heidelberg
Martin Stiemerling is Senior Researcher at the Network Research Division of the NEC Laboratories Europe in Heidelberg, Germany. From June 2007 to Feb 2011 he was at the Computer Networks Group, Institute for Computer Science at the University of Göttingen as a PhD student.
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Transparent Computing and Services,
Yaoxue Zhang, Jianhua Ma, Xiaoming Fu, Martin Stiemerling, International Journal of Cloud Computing, Guest Editorial for Special Issue on Transparent Computing and Services,
InderScience, October 2012.
In the context of cloud computing, computation and storage resources are virtualised, and many elements including software, platform and infrastructure are delivered as a service which can be deployed and scaled out quickly on demand. Transparent computing (TC) is a recently proposed new paradigm designed for providing user-controllable cloud services. To achieve such user controllability, the computing platforms underlying the cloud service provisioning, including the operating system, are not necessarily closely bounded with a single computer, thus becoming also a service.
This special issue introduces a series of state-of-art
research contributions that address the broad challenges of TC and transparent services, covering TC hardware, OSes, management, security, and applications.
PDF [189.0 kB]
NAT/Firewall NSIS Signaling Layer Protocol (NSLP),
Martin Stiemerling, Hannes Tschofenig, Cedric Aoun, and Elwyn Davies, Internet Engineering Task Force, RFC 5973, Next Steps in Signaling (NSIS) Working Group,
This memo defines the NSIS Signaling Layer Protocol (NSLP) for Network Address Translators (NATs) and firewalls. This NSLP allows hosts to signal on the data path for NATs and firewalls to be configured according to the needs of the application data flows. For instance, it enables hosts behind NATs to obtain a publicly reachable address and hosts behind firewalls to receive data traffic. The overall architecture is given by the framework and requirements defined by the Next Steps in Signaling (NSIS) working group. The network scenarios, the protocol itself, and examples for path-coupled signaling are given in this memo.
PDF [135.9 kB]
Quantifying Operational Cost-Savings through ALTO-Guidance for P2P Live Streaming,
Jan Seedorf, Saverio Niccolini, Martin Stiemerling, Ettore Ferranti, Rolf Winter, Proceedings of Incentives, Overlays, and Economic Traffic Control Third International Workshop, ETM 2010, 14-26,
Springer, 978-3-642-15484-3, September 2010.
Application Layer Traffic Optimization (ALTO) is a means for operators to guide the resource provider selection of distributed applications. By localizing traffic with ALTO, Internet Service Providers (ISPs) aim to reduce the amount of costly traffic between Autonomous Systems (ASes) on the Internet. In this paper, we study the potential cost-savings for operators through ALTO-guidance for a specific type of P2P application: P2P Live Streaming. We use datasets that model the Internet’s AS-level routing topology with high accuracy and which estimate the business relationships between connected ASes on the Internet. Based on this data, we investigate different ALTO strategies and quantify the number of costly AS-hops traversed.
Our results show that indeed transmission costs can be reduced significantly for P2P Live Streaming with ALTO. However, for this particularly delay-sensitive type of application, ISPs have to be careful not to over-localize traffic: if peers connect to too many peers which are in the same AS but have low upload capacity, chunk loss increases considerably (resulting in poor video quality). In addition, we demonstrate that if ISPs use an ALTO strategy which recommends peers solely based on the transmission costs from the ISP’s perspective, neither the individual ISPs nor the overall system can substantially decrease transport costs.
Cooperative P2P Video Streaming for Mobile Peers,
Martin Stiemerling and Sebastian Kiesel, IEEE ICCCN 2010 Track on Multimedia and Peer-to-Peer Networking (MP2P),
IEEE, August 2010.
Near-live P2P video streaming is already popular among consumers, but typically this type of application is bound to fixed Internet access, as streaming requires a sustained bitrate over time and is less tolerant to environments with volatile throughput rates. For users moving at speeds larger than walking speed, P2P video streaming is hardly possible, as the achievable throughput for a single peer is insufficient to obtain the video. When multiple peers are interested in the same video stream and they are moving along the same path, they could cooperatively retrieve chunks, instead of acting independently. The participating peers will need to bundle their achievable throughput and coordinate the chunk retrieval. We present such a cooperative P2P video streaming system, introducing a new scheduler and develop a light-weight throughput estimator. 3G cellular link measurements and a simulation study demonstrate the feasibility of our approach for a train scenario.
PDF [2190.0 kB]
A System for Peer-to-Peer Video Streaming in Resource Constrained Mobile Environments,
Martin Stiemerling, Sebastian Kiesel, U-NET CoNext 2009 workshop,
ACM, December 2009.
Peer-to-Peer based near-live video streaming is becoming more and more popular with users of xed-line broadband network access, but it is mostly unavailable to mobile users, as cellular networks, such as GPRS/UMTS, cannot meet the bitrate requirements, while other wireless technologies, such as WLAN, may be fast enough but cover only very limited areas. However, there is a small but important set of scenarios, where several mobile users in close physical proximity are interested in retrieving the same content. We propose a P2P-TV system that enables them to retrieve video chunks in a cooperative way. The coordinated and efficient usage of all wireless resources available to a group of mobile hosts is the key to enable P2P-TV in mobile environments. This paper introduces our general concept. Simulation based studies are presented to assess dierent resource allocation strategies and to demonstrate the feasibility of our approach for delivering near-live TV in resource constrained mobile environments.
unet5141-stiemerling-paper.pdf [457.3 kB]
Traffic Localization for P2P-Applications: The ALTO Approach,
Jan Seedorf, Sebastian Kiesel, and Martin Stiemerling, , Ninth International Conference on Peer-to-Peer Computing (IEEE P2P 2009),
IEEE, September 2009.
Today, most P2P applications do not consider locality on the underlying network topology when choosing their neighbors on the P2P routing layer. As a result, participating peers may experience long delays and peers’ ISPs suffer from a large amount of (costly) inter-ISP traffic. One potential solution to mitigate these problems is to have ISPs or third parties convey information regarding the underlying network topology to P2P-clients through a dedicated service. Following this approach, the IETF has recently formed an Application Layer Traffic Optimization (ALTO) working group for standardizing a protocol to enable P2P applications to obtain information regarding network layer topology. This paper comprises the problem space for such an ALTO approach, taking into account recent developments in the IETF ALTO Working Group. In particular, we will describe requirements for an ALTO protocol identified in the IETF, concrete protocols which have been proposed so far, and the overall challenges. In addition, we will discuss related issues such as privacy considerations, the relationship of an ALTO service with existing caching solutions, discovery mechanisms for an ALTO service, and security considerations.
P2P_2009_industry_session_ALTO_final.pdf [132.8 kB]
TORI: User Provided Future Networking Testbeds,
Martin Stiemerling, Marcus Brunner, Sebastian Kiesel, and Xiaoming Fu, IEEE International Workshop on the Network of the Future, in conjunction with IEEE ICC 2009, Dresden, Germany,
IEEE, June 2009.
The usage of testbeds is considered a key tool for exploring the development of new protocols and network architectures in the area of network research. Testbeds, together with simulations, are the basic tool set of network researchers to drive research, but often it is impossible to get feedback from real deployments and their respective data traffic. Today’s major testbed facilities, e.g., VINI and PlanetLab, aim at emulating the behavior of large-scale networks, but they are still several orders of magnitude smaller than the deployed operational network infrastructure. We argue that it is time to extend network research beyond theoretical and testbed approaches towards a dynamic, peer-to-peer based testbed environment, similar to the approach taken by seti@home and BOINC. We aim at expanding the total number of participating nodes in an experiment and at experimenting on existing operational infrastructure with its entirely uncontrollable environment. Our vision presented in this paper, the Testbed on Real Infrastructure (TORI), includes regular end hosts (peers) in an experiment by deploying and executing the experimental software on these peers and to form an overlay network upon them. The main difference of our TORI approach compared to others is installing new technologies and testing them with the operational infrastructure.
tori-final.pdf [141.2 kB]
ALTO H1/H2 Protocol,
Martin Stiemerling, Sebastian Kiesel, Internet Engineering Task Force, Internet draft (draft-stiemerling-alto-h1h2-protocol-00) , work in progress, Application Level Transport Optimization (ALTO) Working Group,
Many Internet applications are used to access resources, uch as pieces of information or server processes, which are available in several equivalent replicas on different hosts. This includes, but is not limited to, peer-to-peer file sharing applications. The goal of Application-Layer Traffic Optimization (ALTO) is to provide guidance to applications, which have to select one or several hosts from a set of candidates, that are able to provide a desired resource. This memo proposes one possible way of implementing the ALTO protocol, called H1H2. The H1H2 protocol is a client/server protocols between end hosts and ALTO servers that allows two different ways of exchanging data between the server and the client.
draft-stiemerling-alto-h1h2-protocol-00.txt [12.3 kB]
Evaluating P2PSIP under Attack: An Emulative Study,
Jan Seedorf, Frank Ruwolt, Martin Stiemerling, and Saverio Niccolini, IEEE Globecom 2008, New Orleans, LA, USA,
Recently, establishing a VoIP call using a P2P network instead of regular SIP-servers has been proposed; this novel approach to SIP-signaling is commonly referred to as P2PSIP and technically based on a Distributed Hash Table (DHT). P2P networks are advantageous with respect to reliability and scalability. However, securing DHTs against adversary nodes which intentionally interrupt functionality of the network remains a major research problem. In particular, even if a trusted enrollment server is used for secure identifier assignment of participating nodes, attacks on overlay routing by malicious nodes that have successfully joined the network can still severely degrade the lookup service of the DHT.
To gain insight into the ability of callers to reach callees during such attacks on DHT-routing, we present the first P2PSIP implementation that enables to emulate adversary nodes as well as the injection of a large amount of lookup requests (i.e., SIP-Invite requests) in an automated way. Further, we implemented several secure DHT routing algorithms and investigated their effect on the success rate of lookups and the maximum call-setup time in an infiltrated P2PSIP network. In general, our system provides the ability to analyze attacker behavior as well as future novel security techniques in an actual P2PSIP environment with comparably low effort.
PDF [529.3 kB]
Implications and Control of Middleboxes in the Internet,
Xiaoming Fu, Martin Stiemerling, and Henning Schulzrinne, IEEE Network, Special Issue on Implications and Control of Middleboxes in the Internet,
Middleboxes in the Internet have been explored, sometimes quite controversially, in operations, standardization, and the research community for more than 10 years. The main concern, on one hand, has been their contradicting nature to the Internet's end-to-end principle. On the other hand, middleboxes were introduced in the Internet for various reasons. In this special issue we are pleased to introduce a series of state-of-the-art articles on this specific area. These articles cover the subject from a variety of perspectives, offering the readers an understanding of the issues and implications of various middleboxes in the Internet, including their control mechanisms.
PDF [140.6 kB]
Spam Score for SIP,
D. Wing, S. Niccolini, Martin Stiemerling, and Hannes Tschofenig, Internet draft (work in progress),
IETF, February 2008.
This document defines a mechanism for SIP proxies to communicate a spam score to downstream SIP proxies and SIP user agents so they can provide alternate call routing or call handling.
TXT [14.5 kB]
A Network Virtualisation Concept Based on Ambient Networks SATO System,
Martin Stiemerling, Xiaoming Fu, and Marcus Brunner, 1. GI/ITG Fachgespraech Virtualisierung, Paderborn, Germany, pages 33 - 36,
Network virtualization can be one way of fixing the shortcomings of todays Internet but also open the venue for new, unforeseen applications. In this extended abstract, we present a novel approach for network virtualisation based on the Service-Aware Transport Overlay (SATO) concept of Ambient Networks. SATOs introduce on-demand overlay creation and new interfaces to ease applications to use overlays.
PDF [295.8 kB]
A Peer-to-Peer SIP System based on Service-Aware Transport Overlays,
Martin Stiemerling, and Marcus Brunner, Praxis der Informationsverarbeitung und Kommunikation (PIK), Special Issue on Voice over IP, Volume 30, No. 4,
ISBN 978-3-598-01376-8, December 2007.
The Session Initiation Protocol (SIP) traditionally establishes and manages its sessions with centralized servers, which have been challenged by issues with TCP/IP networks right from its beginning, for instance, issues with NAT traversal or network congestions. On the other hand, there are peer-to-peer and overlay techniques that potentially can make SIP working better under various network conditions. Overlay networks can provide a good abstraction from the real network, thus hiding the presence of NATs. Some proposals on peer-to-peer SIP have been recently presented. While these proposals attempted to solve a subset of challenges faced by traditional SIP, such as removing the centralized SIP entities, there is to the best of our knowledge no single solution offering a comprehensive view of the peer-to-peer SIP architecture and operation. This paper presents a novel approach for a peer-to-peer SIP system, using overlay techniques for signalling and media transport in the Internet. This system is based on the Ambient Networks Service-Aware Transport Overlay (SATO) system. The proposed system replaces the traditional SIP proxy/registrar function with a distributed lookup mechanism, adding overlay functionality to the SIP signalling and to the RTP traffic. Moreover, different from previous proposals, our approach deliberately places media/packet relays into the SIP/RTP paths, which allows an efficient session management and media communication.
p2p-sip-system.pdf [456.5 kB]
Peer-to-Peer SIP Implementation Report,
Martin Stiemerling, and Marcus Brunner, Internet Engineering Task Force, Internet draft (draft-stiemerling-p2psip-impl-02), work in progress, Peer-to-Peer SIP (P2PSIP) Working Group,
This memo is an implementation report about the peer-to-peer SIP system developed in the European IST Ambient Networks research project. This system replaces the traditional SIP proxy-registrar function with a distributed lookup mechanism, adds overlay functionality to the SIP signalling and to RTP traffic, takes care about media/packet relay lookup and insertion into the SIP/RTP paths, plus automatic adaptation of the voice transmission according to changing network conditions. Standard, unmodified SIP user agents are used for communication. The presented system is work in progress and this memo is an attempt to gather IETF community feedback about the described approach.
TXT [24.3 kB]