University of Tokyo
Associate Team Home Page
INRIA - NICT and Keio University
INRIA - NICT and University of Tokyo
The SIMULBED project is an associated
team between researchers at INRIA, Keio
University and NICT; it is
financed by INRIA and the Japanese Society for the Promotion of
Science. The SIMULBED associated team started formally for Inria in january
2012 for a duration of three years ending in december 2014. However, from the
japanese side, the SIMULBED project started in April 2012 for
a duration of two years. The initial SIMULBED project was established with the
team of Professor Osamu Nakamura at Keio Univeristy. Professor Nakamura was the
PI from the Japanese side for 2012 and 2013. Hitoshi Asaeda and Hajime Tazaki
has actively contributed to this collaboration. After the end of the two years
AYAME project, we established a new collaboration agreement called DESIGNET
(corresponding to the third year of the SIMULBED associated team from the
french side), with University of Tokyo (Prof. Yuji Sekiya) and NICT (Hitoshi Asaeda is the partner
PI for 2014).
SIMULBED focuses on the design of an efficient
experimentation platform to evaluate new network protocols and architectures.
This project builds on the following state-of-the-art tools and platforms: the open source ns-3 network simulator, PlanetLab testbed and NEPI.
Indeed, the use of both simulators and testbeds to conduct experiments grants a
better insight on the behavior of the evaluated network protocols and
The overall objective of the project is to make available to networking
research community, the SIMULBED platform whose goal is to (1) allow to easily
conduct mixed simulation-experimentation evaluation of
networking protocols and (2) to scale up the size of the PlanetLab
experimental testbed, while maintaining a high degree of realism and
increasing controllability and reproducibility. We leverage of the
experience of both partners in ns-3 and PlanetLab to design and develop
this new plarform. We also use the NEPI unified programming
environment recently developed in the Planète/Diana research team to help in
simplifying the configuration, deployment and run of network scenarios
on the platform.
Context and Problem Statement
Simulators and experimental testbeds are two
different and complementary approaches for the evaluation of network
protocols and they provide a varying degree of repeatability,
scalability, instrumentation and realism.
PlanetLab is one of the most
known experimental testbed in the networking community. It is a
globally distributed testbed designed for network experimentation and
composed of nodes connected to the Internet across the world. PlanetLab
uses container-based virtualization to allow multiple experiments
running independently on the same node while sharing its ressources.
However, the use of network virtualization has a cost: some tasks are
made more complex than in a classical (non-virtualized) environment. In
particular, slivers (which are isolation units for experiments running
in PlanetLab) do not have full root privileges. Therefore operating
system calls to set up routes, tunnels, or IP filters, among others,
are forbidden. One goal of this project is to provide a platform
that makes easier for researchers, the setup, running and evaluation of
new protocols and architectures.
Ns-3 is the first network
simulator that converts transparently and efficiently network packets
to and from simulation objects, hence enabling transparent support for
real-time simulation in every ns-3 model. This provides a high degree
of realism. Therefore it will be easy to use it as a real-time emulator
in a larger testbed. It will also allows to execute directly within the
simulator unmodified network protocol implementations and applications,
using the Direct Code Execution (DCE) feature. Using DCE, ns-3
trades off scalability for realism by embedding within the simulator
existing protocol implementations that were never designed to run in a
simulator. It makes possible to considerably increase the realism of a
simulation while retaining its repeatability and ease of debugging. It
also makes it trivial to repeat and compare the result of the same
experiment in a testbed by using the same protocol implementation in
both cases. In DCE, the Virtualizing Dynamic Loader (VDL) Executable
and Linkable Format (ELF) loader is used to both virtualize access to
every global and static variable and to redirect function calls to
system facilities from their normal implementation to a simulation
implementation. However, the memory and CPU cost of virtualizing a
single external protocol implementation for execution within the
simulator should be maintained as low as possible to be able to run
simulations which process many packets per second and include a large
numbers of instances of this protocol implementation. Moreover, the
current DCE library is still incomplete from the perspective of
replacing all the functionality provided by normal system libraries.
Therefore, in this project, we plan to enhance DCE and increase its functionality coverage by adding the
missing wrapper functions.
Another objective of this project is to allow to run
hybrid networking scenarii involving both simulators and real nodes.
While these scenarii are simple to state, the complexity of deploying,
and configuring correctly these experiments put them out of reach of
most experimenters. Indeed, the complexity of setting them up is very
high: users must configure compatibly both their testbed and their
simulation, which makes it impossible to use the native setup
capabilities of each experimentation tool and thus, requires a lot of
manual work. Then, another contribution of this project is to implement
mechanisms to simplifying the description and deployment of such mixed
network experiments scenarii. Specifically, we plan to extend the NEPI
unified programming environment developed at Planète to fit the
specific requirements of the SIMULBED platform. We need also to propose
some algorithms that help in distributing a networking simulation
scenario in multiple real nodes. This problem is challenging because it
is necessary to minimize the traffic exchanged between real nodes and
to ensure to keep the CPU load of real nodes as low as possible.
Note that in Japan the project officially started on June 2012 with the kick-off meeting at INRIA.
Period January 2012 - September 2012:
As part of the efforts to simplify set-up and execution of mixed
experiments, NEPI was extended to automate deployment and customization
of routing overlays on PlanetLab. Thanks to this ability and to the
additional support to deploy and control ns-3 simulations on PlanetLab
nodes, it is now possible through NEPI to conduct experiments where
PlanetLab nodes and ns-3 simulations are part of a same routing
overlay. This extension to NEPI not only allows a better control over
the routing between PlanetLab nodes, thanks to the use of customizable
tunnels, but it also enables researchers to easily scale PlanetLab
experiments using ns-3 simulations. Additionally, support for easy
experimentation with CCNx on
PlanetLab was added to NEPI. CCNx is an interesting use case for NEPI
since it is a promising technology for future Internet architecture
with a rapidly growing industrial and academic community. This work was
presented to the community on the last CCNx conference.
Work is underway to support a fourth experimentation environment, OMF,
in NEPI, to enable wireless network experimentation. NEPI will interact
with the OMF resource control layer by implementing the OMF XMPP protocol.
In the future we foresee to support the ability to deploy ns-3
simulations in OMF nodes and to integrate the simulated network in a
same overlay with OMF nodes. Finally, extensions to support automatic
IP address assignment and routing table population during experiment
design time are being added to NEPI with the objective of easing the
high time expense involved in manual configuration of large experiment
DNEmu was also introduced to provide smooth experimentation control
over distributed PlanetLab nodes with ns-3. As NEPI does, DNEmu is also
able to control and synchronize the experimental scenario among
multiple nodes, but DNEmu more focuses on the ns-3 specific feature and
tries to reduce the dependency of external software and toolset. This
work was presented at the WNS3 workshop and on TridentCom'12
Concerning Direct Code Execution (DCE) of ns-3, we have added the
support the recent 3.4.5 Linux kernel, and different versions of Fedora
and Ubuntu Linux distributions. Other works include the creation of
an helper to automatically create the static routes for
a static network like the helper existing in ns-3, and the support
of Message Passing
Interface (MPI) for two loaders of DCE (CoojaLoader and
CopyLoader). Further details on DCE functionalities added and
planned to be added can be found in bugzilla.
Period October 2012 - October 2013:
Our work on the Simulbed experimentation platform focused on two main
directions: Direct Code Execution (DCE) framework and Network
Experiment Programming Interface (NEPI).
We released version 1.1 of DCE on September 1st, 2013. Several new features have been added. First, we added aspect-based tracing,
which allows us to use tracing facility in DCE when simulating
unmodified code. This feature is important for debugging and protocol
analysis purposes as it enables to investigate which function is called
or how many messages of a particular protocol are exchanged for
example. We introduced a development suite for network protocol
development that includes code coverage measurement using the gcov
tool, memory analysis under distributed protocol operation with
valgrind, and distributed code debug with gdb. In addition to above new
feature supports, we wrote a public web page for DCE (see URL http://www.nsnam.org/overview/projects/direct-code-execution/) along with manuals (see URL http://www.nsnam.org/docs/dce/manual/html/index.html),
and proposed a stable software release cycle so that users can choose
to use either the stable DCE version or the latest experimental
version. We also designed the bake building and integration tool to
make easier the DCE installation procedure, see URL http://www.nsnam.org/docs/bake/tutorial/html/index.html.
- Direct Code Execution (DCE)
Two papers on DCE have been accepted in 2013. The first one introduces
DCE Cradle, a feature that enables to use ns-3 native applications over
DCE Linux kernel stack. DCE Cradle utilizes standard Linux kernel
network stacks and provides transparent socket interfaces to the ns-3
applications. This allows us to study Linux kernel protocols with
various useful applications of ns-3, such as trac generators or
routing protocols. This paper presents the architecture, a use case
involving the DCCP protocol and some benchmarks. The second paper
describes the DCE framework, and has just been accepted at the
prestigious ACM CoNEXT conference. It describes in detail the
architecture of DCE, reports on packet processing benchmark and
showcases key features of the framework with various use cases. This
paper also demonstrates that DCE can be used to write runnable papers,
i.e., papers where researchers can easily reproduce experiments shown
A tutorial on how to experiment CCN using the CCNx implementation
from PARC with DCE has been presented at the ICN workshop in January
2013. A demonstation on how to use DCE with different use cases has
been done in the ACM MSWiM conference in Barcelona on November 4, 2013.
In September 2013, we released version 3.0 of NEPI,
the framework that provides an experiment description language to
describe experiments during the design stage, and the mechanisms to
automate the deployment and control of experiments and collect results,
during the execution stage. The previous version of the experiment
description language lacked sufficient expensiveness to describe
experimental work flows (i.e. to specify a sequence of events that need
to take place during the experiment in a flexible way). Also, to
support a larger set of experimentation scenarios with NEPI, we needed
a more easily extensible architecture to make it easier the support of
new experimentation environments and new types of resource (e.g.
virtual machines, switches, tunnels, etc).
- Network Experiment Programming Interface (NEPI)
Version 3.0 of NEPI includes a re-design of its
architecture to allow expressing work flows as part of the experiment
description, and to enable easier extensibility of NEPI to support new
experimentation environments and resources. This new architecture adds
to NEPI the capability to automate execution of experiments in any
SSH-enabled Linux testbed (PlanetLab included), and in OMF-based
wireless testbeds. A full release of NEPI, including
enhanced user documentation, a new WEB site, a wiki page and a bugzilla
bug reporting page, is planned for December 2013.
Finally we have used NEPI to evaluate the
performance of CCN overlays on top of the Internet. We constructed
different overlay topologies on PlanetLab, in which we varied the
topology configuration, the trafic patterns and different CCN
parameters with the objective to find correlations between these
variables and the performance obtained. A paper is in preparation and
the capabilities of using NEPI to easily run CCNx experiments in
realistic wired and wireless environments has been demonstrated in the
CCNx workshop at PARC in September 2013.
Period October 2013 - October 2014:
This year, our work includes enhancements of the DCE and NEPI
frameworks, developement of the CUTEi testbed involving NEPI,
and the design on Contrace, a new measurement tool for
information-centric networking architectures as detailed as follows:
We have implemented missing wrapping code between ns-3 and DCE in order to be
able to launch with NEPI hybrid experiments including real application
codes running over ns-3 through DCE. Actually, the most common language to write DCE simulation scripts is C++. But
C++ implementations may be difficult for new users, and time consuming
even for experienced users. We believe that a scripting language like Python is
helpful to simplify experimentations. Python bindings are wrapping code required to
translate Python calls to corresponding C++ calls. Furthermore, these
bindings makes possible running DCE from NEPI.
We added the support of OpenFlow (OF) protocol through the use of
Open vSwitch in DCE. Using DCE helps in reducing the
development cost to port the latest flavor of OpenFlow in ns-3
and allows to simulate with ns-3
with the latest features of OF with minimal cost. Such a work makes it
possible to simulate and evaluate in a realistic way wireless Software
Defined Networking solutions. Indeed, the most used SDN emulator tool,
mininet, can only emulate point-to-point physical links using virtual
Ethernet pairs (e.g., MAC layer is ignored), and it can not provide
mobility models for wireless nodes. To make DCE able to run Software
Defined Networks, we started to support OpenFlow NOX controller and
Open vSwitch. The actual NOX binary is executed on a simulated ns-3
node. OpenFlow wireless routers are simulated using the Open vSwitch
distribution with data-path kernel module support as it is widely used.
DCE provides a mechanism to incorporate such a kernel module based
This has been demonstrated at the 17th ACM International
Conference on Modeling, Analysis and Simulation of Wireless and Mobile
Systems, held in Montreal Canada.
In 2014 we released two new versions of DCE: 1.3
(released on July 9th), and 1.4 (released on September 17th). Version
1.3 was a major improvement, introducing the Python bindings and the
FreeBSD network stack, along support for new protocols (SCTP and IPv6
sockets for DCE Cradle: TCP6, UDP6, RAW6, DCCP6, SCTP6). It also
included a number of minor improvements and bug fixes.
Version 1.4 has been an incremental version, including mainly bug fixes
and new API support. Most of the new APIs were required to improve the
support to NEPI. The two versions also include improvements on the
documentation and user manuals.
The capabilities of using NEPI to easily run CCNx experiments in
realistic wired and wireless environments has been demonstrated in the
CCNx workshop at PARC in September 2013. Moreover, we have demonstrated
NEPI to evaluate the performance of Information-Centric Networking (ICN)
solutions. Such a development and evaluation environment that enables
both controllable and realistic experimentation is needed to thoroughly
understand how ICN solutions would behave in real life deployment. We
demonstrated the benefits of our solution by showing how complete
experimental studies can be carried out with minimum manual intervention
and experiment set-up overhead, in both emulation and live environments.
We have developed CUTEi, which employs the Linux container (LXC)
lightweight virtualization mechanism for node design and enables
testbed users to evaluate ICN applications and protocols. It enables
testbed users to share the major or common ICN software and
applications on top of CUTEi nodes. In addition to OS commands and
libraries, CCNx, NDNx, and other software and libraries are currently
pre-installed in a Logical Volume (LV) of each CUTEi node as basic ICN
components. CUTEi adopts NEPI to automate experiment description,
distributing codes, and executing network experiments on network
evaluation platforms: The user first uses a Python-based language to
describe the experiment as a graph of interconnected components,
including CCN nodes, FIB configuration, and CCN applications. Then,
s/he instructs NEPI how to deploy the experiment. In the CUTEi testbed,
NEPI uses an SSH-based backend to automate to run CCN applications
(e.g., ccncat) on user containers. During and after execution of the
experiment, the user can ask NEPI to download CCN logs and other
collected results from his/her user containers. CUTEi testbed is
currently deployed in 9 sites, INRIA (FR), NICT, Keio U., Waseda
U. (JP), Tsinghua U. (CN), SNU (KR), U. Florida (US), etc.
- Container-based Unified TEstbed for iCN (CUTEi) development
As information flow in ICN/CCN is based on named data requesting,
in-network caching, and forwarding—which are unique and can be
independent of IP routing. Hence common IP-based network tools such as
ping and traceroute can neither trace a forwarding path in CCN nor
feasibly evaluate CCN performance. We have designed
“contrace," a network tool for CCNs that can be used to
investigate 1) Round-Trip Time (RTT) between content forwarder and
consumer, 2) the states of in-network cache per name prefix, and 3) the
forwarding path information per name prefix. The results of experiments
conducted using contrace on a CCN topology formed on DCE/NS3 not only
confirm the behavior but also that contrace can trace paths via name
prefix, measure RTT, and show the caching information in CCN.
We submitted a paper describing Contrace with use cases to a
- Contrace measurement tool for CCN development
The members of the associated team has worked closely together to
ensure high visibility of the project resutls. Several publications
published in large audience journal and international conferences and
workshops. The associated team members also presented several
tutorials, demonstrations and posters at specialized conferences,
workshops and summer schools. We also have disseminated our work to
increase the DCE and NEPI user
community by promoting the use of these two frameworks in classrooms
(in particular, Ubinet Master, UPMC and Telecom ParisTech students) and
in research institutions through the Fed4Fire European FP7 project.
include how to write runanble papers, how to reproduce other
researchers results using DCE and evaluate further their protocols in
extended scenarios using both DCE and NEPI.
- In 2014 :
- February 18-20: Meeting at INRIA, (visit of Hitoshi Asaeda and Hajime Tazaki)
- June 23-26: Meeting at INRIA, (visit of Hitoshi Asaeda and Kazuhisa Matsuzono)
- November 18-20: Meeting at NICT and Univ. of Tokyo, (visit of Hardik Soni and Thierry Turletti)
- In 2013 :
- March 5-7: Visit at INRIA of Hajime Tazaki during the WNS-3 workshop
- June 24-27: Meeting at INRIA, (visit of Hitoshi Asaeda and Hajime Tazaki)
- October 7-9: Meeting at NICT, (visit of Alina Quereilhac, Emilio Mancini and Thierry Turletti)
- November 4-6: Meeting during the MSWiM'13 conference in Barcelona (Emilio Mancini and Hajime Tazaki)
- In 2012 :
- June 4-8 : Kick-off meeting at INRIA, (visit of Hitoshi Asaeda, Kazuhisa Matsuzono and Hajime Tazaki)
- September 11-13 : Visit at INRIA of Hajime Tazaki during the CCNxCon'12 workshop
- November 26-30 : Meeting at NICT, (visit of Alina Quereilhac, Thierry Turletti and Frédéric Urbani)
- Hitoshi Asaeda, Ruidong Li, and Nakjung Choi, “Container-Based Unified Testbed for Information-Centric Networking”, to appear in IEEE Network Magazine, end 2014.
- D. Camara, H. Tazaki, E. Mancini, M. Lacage, T. Turletti, W. Dabbous, "DCE: Test the real code of your protocols and applications over simulated networks", in IEEE Communication Magazine, Network Testing Series, March 2014.
- Y.-H. Kim, A. Quereilhac, M.A. Larabi, J. Tribino, T. Parmentelat, T. Turletti, W. Dabbous, "Enabling Iterative Development and Reproducible Evaluation of Network Protocols", in Computer Networks journal 63: 238-250 (2014).
- A. Quereilhac, D. Camara, T. Turletti, W. Dabbous, "Experimentation with large scale ICN multimedia services on the Internet made easy", invited paper, IEEE COMSOC MMTC E-Letter 8, 4 (2013), pp. 10-12.
Conferences and Workshops
- Hajime Tazaki, Frederic Urbani, Emilio Mancini, Mathieu Lacage, Daniel Camara, Thierry Turletti, Walid Dabbous, ``Direct Code Execution: Revisiting Library OS Architecture for Reproducible Network Experiments'', in Proc. of ACM CoNEXT conference, Santa Barbara, CA, Dec. 9-12, 2013.
- Hajime Tazaki, Frederic Urbani, Thierry Turletti, ``DCE Cradle: Simulate Network Protocols with Real Stacks'', in Proc. of ns-3 workshop at Simutools, Cannes, March 5, 2013. [Best Award Paper]
- Daniel Camara, Frederic Urbani, Mathieu Lacage, Thierry Turletti, Walid Dabbous, ``Simulation Platform for Content Centric Networks Protocols Development'' [slides], CCNxCon workshop, September 12-13, 2012, Sophia Antipolis, France.
- Claudio Freire, Alina Quereilhac, Thierry Turletti and Walid Dabbous,
'`Automated deployment and customization of routing overlays on PlanetLab'', [slides], in Proc. ICST TridentCom conference, June 11-13, 2012, Thessaloniki, Greece.
- Hajime Tazaki and Hitoshi Asaeda, ``DNEmu: Design and Implementation of Distributed Network Emulation for Smooth Experimentation Control'', in Proc. ICST TridentCom conference, June 11-13, 2012, Thessaloniki, Greece.
- Alina Quereilhac, Priya Mahadevan, ``Evaluating Costs of CCN Overlays'', poster at CCNxCon workshop, Palo Alto, CA, Sep 5-6, 2013.
- Daniel Camara, ``CCNx on ns-3'', remote presentation at ICN workshop, TIP 2013, Honolulu, Jan 15, 2013.
- Alina Quereilhac, Thierry Turletti and Walid Dabbous, ``Managing heterogeneous ns-3 experiments with NEPI'', poster at WNS3 workshop, March 23, 2012 Desenzano, Italy.
- Hajime Tazaki, ``An Architecture for Distributed Network Emulation'', poster at WNS3 workshop, March 23, 2012 Desenzano, Italy.
- A. Quereilhac, D. Saucez, P. Mahadevan, T. Turletti, and W. Dabbous, "Demonstrating a unified ICN development and evaluation framework", (poster), demo session of the ACM Information-Centric Networking (ICN), Paris, September 2014.
- E. Mancini, H. Soni, T. Turletti, W. Dabbous, H. Tazaki, "Demo Abstract: Realistic protocol and SDN Experiments with Direct Code Execution and ns-3", (poster), Demo at ACM MSWiM, Montreal, Canada, September 21-26, 2014.
- Hajime Tazaki, Emilio Mancini, Daniel Camara, Thierry Turletti, Walid Dabbous,
``Direct Code Execution: Increase Simulation Realism using Unmodified
Real Implementations'', demo at ACM MSWiM, Barcelona, Spain, Nov. 3-8
- Alina Quereilhac,Julien Tribino, Thierry Turletti, Walid Dabbous, ``Running Live CCNx Experiments on Wireless and Wired Testbeds with NEPI'', demo at CCNxCon workshop, Palo Alto, CA, Sep 5-6, 2013.
- Alina Quereilhac, Anshuman Kalla, Thierry Turletti, Walid Dabbous, ``Easy CCNx experimentation on PlanetLab'' [poster], demo at CCNxCon workshop, September 12-13 2012, Sophia Antipolis, France.
- Alina Quereilhac, Claudio Freire, Thierry Turletti, Walid Dabbous, ``Controllable packet prioritization on PlanetLab using NEPI'', demo at ICST TridentCom conference, June 11-13, 2012, Thessaloniki, Greece.
- Osamu Nakamura (PI 2012-13), Professor at Keio Univ. (2012-13)
- Hitoshi Asaeda (PI 2014), Senior Researcher at NICT (2012-14)
- Walid Dabbous (PI), Senior Researcher at INRIA (2012-14)
- Daniel Camara, Research Engineer at INRIA (2012-13)
- Tsuyoshi Hisamatsu, Postdoc at Keio Univ. (2012)
- Ruidong Li, Researcher at NICT (2014)
- Emilio Mancini, Senior Research Engineer at INRIA (2013-14)
- Kazuhisa Matsuzono, Researcher at NICT (2014)
- Alina Quereilhac, PhD Student at INRIA (2012-14)
- Yuji Sekiya, Associate Professor at Univ. of Tokyo (2014)
- Mahdi Shoja, Master Student at INRIA (2014)
- Hardik Soni, Master Student at INRIA (2014)
- Hajime Tazaki, Researcher at NICT (2012-13)
- Julien Tribino, Research Engineer at INRIA (2012-14)
- Thierry Turletti, Senior Researcher at INRIA (2012-14)
- Frédéric Urbani, Research Engineer at INRIA (2012)