Gang is a joined team between INRIA, CNRS and Paris Diderot University, through the “laboratoire d'informatique algorithmique, fondements et applications”, LIAFA(UMR 7089).

Our goal is to develop the field of graph algorithms for networks. Based on algorithmic graph theory and graph modeling we want to understand what can be done in these large networks and what cannot. Furthermore, we want to derive practical distributed algorithms from known strong theoretical results. Finally, we want to extract possibly new graph problems by focusing on particular applications.

The main goal to achieve in networks are efficient searching of nodes or data, and efficient content transfers. We propose to implement strong theoretical results in that domain to make significant breakthrough in large network algorithms. These results concern small world routing, low stretch routing in doubling metrics and bounded width classes of graphs. They are detailed in the next section. This implies several challenges:

testing our target networks against general graph parameters known to bring theoretically tractability,

implementing strong theoretical results in the dynamic and distributed context of large networks.

A complementary approach consists in studying the combinatorial and graph structures that appear in our target networks. These structures may have inherent characteristics coming from the way the network is formed, or from the design goals of the target application.

Recent years have brought tremendous progress along the peer-to-peer paradigm allowing large scale decentralized application to be practically deployed. The main achievement of this trend is certainly efficient content distribution through the BitTorrent protocol . The power of peer-to-peer content distribution is to rely on the upload capacity of the node interested in receiving the content. This allows to scale to very large number of participants. The main breakthrough of BitTorrent resides in its “tit for tat” strategy inspired from game theory to give incentive to cooperate. For that purpose, a peer preferentially uploads preferentially offering best reciprocity. This kind of preferences induces an interesting graph structure with ordered neighborhoods. Understanding the dynamic behavior of such affinity graphs is an important for stabilizing the performance of such protocols.

A second major achievement of the peer-to-peer paradigm concerns indexing with distributed hashtables , , . The idea behind these proposals is to organize the peers into a structure close to well known graphs with low diameter such as hight dimension torus, hypercube or de Bruijn graph. Efficient routing to the node storing a given key is then guaranteed. This academic work has lead to practical basic indexing facilities by introducing redundancy in the structure . This is typically the kind of approach we want to promote: from known efficient theoretical solutions to practical working protocols. We have contributed to this trend by introducing de Bruijn based solutions , with redundancy in the contact graph to resist node churn.

Popularized emerging properties include degree distributions observed to be power law in many networks or clustering coefficient observed to be high in social networks or low average distances. This last point gave the denomination of “small worlds” for this type of networks. Some work , try to give models that give raise to such statistical properties. In that line, numerous results such as try to derive efficient algorithms based only on these statistical properties. This particular approach tends to concentrate load on nodes with high degrees and may not be suited for applications where nodes have similar capacities. Other interesting work try to explain this statistical observation forms an inherent optimization problem operating when constructing the network.

On the other hand, in its seminal paper , Kleinberg focuses on the algorithmic aspects of such social networks and shows how adding random links to a torus can produce efficient greedy routing. This result has been extend to more general classes of graphs , such as bounded growth metric graphs . However, this augmentation process is not always feasible . Such theoretical work is particularly interesting for overlay networks where this augmenting process simply consists in opening additional connections.

Bounded growth and doubling metrics generalize Euclidean metrics. A metric has bounded growth if the size of any ball increases by a factor not larger than
2
^{d}when its radius is doubled
. A metric is doubling if any set of diameter
Dcan be covered with at most
2
^{d}sets of diameter
D/2
. In both cases, the smallest acceptable value of
dis called the dimension of the metric. The metric of any
ddimensional Euclidean space has bounded growth dimension
O(
d). Any bounded growth metric of dimension
dhas doubling dimension
O(
d). The doubling metric is the most general and has the additional property of being inherited by subspaces: the metric induced by a doubling metric on a subset of
nodes is also doubling. For example, sampling nodes in an Euclidean space always results in a doubling metric.

As networks are embedded in our usual three dimensional space, it is legitimate to think than some network metrics may be modeled through doubling metrics. Recent results thus investigate network problems for the restricted classes of graphs with bounded growth or doubling metric , , , . However, the doubling nature of large networks such as the Internet has still not be tested.

Many graph parameters such as treewidth, branchwidth, rankwidth, cutwidth, cliquewidth ...have been introduced in recent years , to measure the structure of a given graph. These parameters are of course NP-complete to compute, but when it can be proved that for a given class of graphs the parameter is bounded by a constant then it can be proved using graph grammars (see Courcelle's fundamental work) that most of the optimization problems on this class are polynomially tractable, and sometimes we know the existence of a linear algorithm (but the hidden constant can be very high !)

The most famous parameter, namely the treewidth captures the distance of the graph to a tree, and therefore when the treewidth is small a dynamic programming approach can be used .

Despite some promising results, applications of these notions has still to be done for networks, in a practical perspective.

Application domains include evaluating Internet performances, the design of new peer-to-peer applications, enabling large scale ad hoc networks and mapping the web.

The application of measuring and modeling Internet metrics such as latencies and bandwidth is to provide tools for optimizing Internet applications. This concerns especially large scale applications such as web site mirroring and peer-to-peer applications.

Peer-to-peer protocols are based on a all equal paradigm that allows to design highly reliable and scalable applications. Besides the file sharing application, peer-to-peer solutions could take over in web content dissemination resistant to high demand bursts or in mobility management. Envisioned peer-to-peer applications include video on demand, streaming, exchange of classified ads,...

Wifi networks have entered our every day life. However, enabling them at large scale is still a challenge. Algorithmic breakthrough in large ad hoc networks would allow to use them in fast and economic deployment of new radio communication systems.

The main application of the web graph structure consists in ranking pages. Enabling site level indexing and ranking is a possible application o f such studies.

*Gossip*protocols are communication protocols in which, periodically, every node of a network exchanges information with some other node chosen according to some (randomized) strategy.
These protocols have recently found various types of applications for the management of distributed systems.
*Spatial*gossip protocols are gossip protocols that use the underlying spatial structure of the network, in particular for achieving the "closest-first" property. This latter property
states that the closer a node is to the source of a message the more likely it is to receive this message within a prescribed amount of time. Spatial gossip protocols find many applications,
including the propagation of alarms in sensor networks, and the location of resources in P2P networks. In
, we design a sub-linear spatial gossip protocol for arbitrary graphs
metric. More specifically, we prove that, for any graph metric with maximum degree
, for any source
sand any ball centered at
swith size
b, new information is spread from
sto all nodes in the ball within
rounds, with high probability. Moreover, when applied to general metrics with uniform density, the same protocol achieves a propagation time of
O(log
^{2}bloglog
b)rounds.

An edge-Markovian process with birth-rate
pand death-rate
qgenerates sequences of graphs
(
G
_{0},
G
_{1},
G
_{2}, ...)with the same node set
[
n]such that
G_{t}is obtained from
G_{t-1}as follows: if
then
eE(
G_{t})with probability
p, and if
eE(
G_{t-1})then
with probability
q. Clementi et al. (PODC 2008) analyzed thoroughly information dissemination in such dynamic graphs, by establishing bounds on their flooding time — flooding is the basic mechanism in
which every node becoming aware of an information at step
tforwards this information to all its neighbors at all forthcoming steps
t^{'}>
t. In
, we establish tight bounds on the complexity of flooding for all
possible birth rates and death rates, completing the previous results by Clementi et al. Moreover, we note that despite its many advantages in term of simplicity and robustness, flooding
suffers from its high bandwidth consumption. Hence we al! so show that flooding in dynamic graphs can be implemented in a more parsimonious manner, so that to save bandwidth, yet preserving
efficiency in term of simplicity and completion time. For a positive integer
k, we say that the flooding protocol is
k-active if each node forwards an information only during the
ktime steps immediately following the step at which the node receives that information for the first time. We define the
*reachability threshold*for the flooding protocol as the smallest integer
ksuch that, for any source
s[
n], the
k-active flooding protocol from
scompletes (i.e., reaches all nodes), and we establish tight bounds for this parameter. We show that, for a large spectrum of parameters
pand
q, the reachability threshold is by several orders of magnitude smaller than the flooding time. In particular, we show that it is even constant whenever the ratio
p/(
p+
q)exceeds
log
n/
n. Moreover, we also show that being active for a number of steps equal to the reachability threshold (up to a multiplicative constant) allows the flooding protocol
to complete in
*optimal*time, i.e., in asymptotically the sa! me number of steps as when being perpetually active. These results demonstrate that flooding can be implemented in a practical and
efficient manner in dynamic graphs. The main ingredient in the proofs of our results is a reduction lemma enabling to overcome the time dependencies in edge-Markovian dynamic graphs.

We consider the fully distributed Video-on-Demand problem, where
nnodes called
*boxes*store a large set of videos and collaborate to serve simultaneously
nvideos or less between them. It is said to be
*scalable*when
(
n)videos can be distributively stored under the condition that any sequence of demands for these videos can always be satisfied. Our main result consists in
establishing a threshold on the average upload bandwidth of a box, above which the system becomes scalable. We are thus interested in the normalized upload capacity
of a box. The number
mof distinct videos stored in the system is called its catalog size.

Based on these results, we provide some guidelines for setting the system parameters: the use of cache strongly improves system performance; popularity based allocation techniques can be sensitive and bring little improvement; dynamic distribution algorithms are needed only in extreme scenarios while static ones are commonly sufficient.

In unstructured P2P live streaming systems the stream is not forwarded as a continuous flow of data but is divided in a series of pieces (chunks), that are injected in the system by a source and exchanged among peers in order to retrieve the complete sequence and play out the stream. Data exchange is therefore driven by chunk exchange algorithms run locally by nodes, which can be described by their chunk/peer selection policies. It turns out that the most popular commercial peer-to-peer systems for live streaming like CoolStreaming, PPLive, SopCast, are based on such an unstructured approach.

The performance trade-offs of chunk exchange algorithms have been deeply analyzed for homogeneous systems, where all peers have the same upload capacity. In
we analyze chunk diffusion algorithms designed for heterogeneous
environments, where peers have different upload capacities. We focus on the peer selection process and propose a generic model that encompasses a large class of algorithms. We derive
recursive formulas to describe the chunk diffusion function of a generic
*latest blind chunk / resource aware peer*selection scheme. By means of simulations, we analyze the resource awareness-agnostism trade-offs on the peer selection process and the impact
of the source distribution policy in non-homogeneous networks. We highlight that the early diffusion of a given chunk is crucial for its overall diffusion performance, and a fairness
trade-off arises between the performance of heterogeneous peers, as a function of the level of awareness. Moreover, we show the critical role the source selection policy plays on chunk
diffusion performance.

A good diffusion scheme is indeed essential for the performance of an unstructured P2P live streaming system. For a given scheme however, an optimization at a detailed level is also important. This involves the fine tuning of dissemination parameters, such as chunk size, receiver buffer size, number of peers to probe, etc. In , we investigate optimal sizing of chunks and probe sets, i.e. the number peers a given node probes before transmitting chunks. The analysis is performed by means of an event-based simulator. We show that the chunk size significantly impacts performance and that it should fall within a given range which is mostly determined by the median RTT of the network and the stream rate. We also show that the size of the probe set affects performance of diffusion schemes, and, in particular, a probe set larger than the actual number of concurrent connections may improve miss ratio/delay performance by modifying the suitable chunk size ranges.

Network traffic is increasing in size and is becoming more and more dynamic leading to unpredictable and highly variable traffic patters. Multi-path routing is considered a powerful approach to deal with the aforementioned traffic patterns, mostly for intra-domain TE, inter-AS path selection under the same ISP, routing in wireless networks and metropolitan access networks. Through an optimization framework in we quantify the benefit in using multi-path routing and we analyze the role network topology and traffic matrix play on multi-path routing performance. Starting from the insights inferred from this analysis in , , we introduce MIRTO, which is a distributed multi-path routing protocol that jointly uses best path selection and flow control for optimality and stability. In , we introduce an analytical model in order to compare different routing schemes using fluid ordinary differential equations (ODEs). We model the sending rate of MIRTO and of other two recently proposed algorithms, TEXCP and TRUMP, and we compare their performance on the Abilene network topology with FIFO and Fair-Queuing scheduling. We show MIRTO consumes less network resource but suffers of longer convergence times because it relies on simpler feedbacks and it is not equation based. We also highlight that Fair-Queuing scheduling leads to sub-optimal global resource allocations because it imposes fairness at link level. We implement MIRTO, TEXCP and TRUMP in a software prototype in order to analyze their performance in real networks under real traffic conditions. Results reported in confirm the trends already highlighted by our analytical analysis, and show that dynamic yet stable traffic engineering is not only feasible but expected with increasing interest by network operators.

This paper considers the routing problem in dynamic trees under the fixed-port model, in which an adversary chooses the port numbers assigned to each node. We present two routing schemes
for dynamic trees that maintain labels of asymptotically optimal size using extremely low average message complexity (per node). Specifically, we first present a dynamic routing scheme that
supports additions of both leaves and internal nodes, maintains asymptotically optimal labels and incurs only
O(log
^{2}n/log
^{2}log
n)average message complexity. This routing scheme is then extended to supports also deletions of nodes of degree at most 2. The extended scheme incurs
O(log
^{2}n)average message complexity and still maintains asymptotically optimal labels.

We would like to point out that the best known routing scheme for dynamic trees that maintains asymptotically optimal labels in the fixed port model has very high average message complexity, namely, . Moreover, that scheme supports additions and removals of leaf nodes only.

We look at routing and scheduling problems on Kelly type networks where the injection process is under the control of an adversary. The novelty of the model we consider is that the adversary injects requests of distinct types. Resources are subject to switch-over delays or setups when they begin servicing a new request class. In this new setting, we study the behavior of sensible policies as introduced by Dai and Jennings .

We first show that the model is robust in the sense that under some mild conditions universal stability of work conserving packet routing protocols is preserved for natural variants of the underlying model. Also, the model's equivalence to so called token networks is established.

We adapt, to the multi-type request and setup setting, standard arguments for proving stability. Nevertheless, we provide counterexamples that show that for several reasonable adaptations of contention resolution protocols to the multi-type case, stability results do not carry over from the single-type scenario. This motivates us to explore fluid model based arguments that could be used for proving stability for a given network. Specifically we show analogues of results obtained by Gamarnik but in the multi-type request with setups scenario.

The
(
M,
W)-controller, originally studied by Afek, Awerbuch, Plotkin, and Saks, is a basic distributed tool that provides an abstraction for managing the consumption of a
global resource in a distributed dynamic network. The input to the controller arrives online in the form of requests presented at arbitrary nodes. A request presented at node
ucorresponds to the “desire” of some entity to consume one unit of the global resource at
uand the controller should handle this request within finite time by either granting it with a permit or denying it. Initially,
Mpermits (corresponding to
Munits of the global resource) are stored at a designated root node. Throughout the execution permits can be transported from place to place along the network's links so that they can
be granted to requests presented at various nodes; when a permit is granted to some request, it is eliminated from the network. The fundamental rule of an
(
M,
W)-controller is that a request should not be denied unless it is certain that at least
M-
Wpermits are eventually granted. The most efficient
(
M,
W)-controller known to date has message complexity
, where
Nis the number of nodes that ever existed in the network (the dynamic network may undergo node insertions and deletions).

In this paper we establish two new lower bounds on the message complexity of the controller problem. We first prove a simple lower bound stating that any
(
M,
W)-controller must send
messages. Second, for the important case when
Wis proportional to
M(this is the common case in most applications), we use a surprising reduction from the (centralized) monotonic labeling problem to show that any
(
M,
W)-controller must send
(
Nlog
N)messages. In fact, under a long lasting conjecture regarding the complexity of the monotonic labeling problem, this lower bound is improved to a tight
(
Nlog
^{2}N). The proof of this lower bound requires that
N=
O(
M)which turns out to be somewhat inevitable due to a new construction of an
(
M,
M/2)-controller with message complexity
O(
Nlog
^{2}M).

On a more prospective way, is intended more to ask questions than to give answers. Specifically, we consider models for labeling schemes, and discuss issues regarding the number of labels consulted vs. the sizes of the labels.

Recently, quite a few papers studied methods for representing network properties by assigning
*informative labels*to the vertices of a network. Consider some graph function
fon pairs of vertices (for example,
fcan be the distance function). In an
f-labeling scheme, the labels are constructed in such a way so that given the labels of any two vertices
uand
v, one can compute the function
f(
u,
v)(e.g. the graph distance between
uand
v) just by looking at these two labels. Some very involved lower bounds for the sizes of the labels were proven. Also, some highly sophisticated labeling schemes were developed to
ensure short labels.

In this paper, we demonstrate that such lower bounds are very sensitive to the number of vertices consulted. That is, we show several constructions of such labeling schemes that beat the
lower bounds by large margins. Moreover, as opposed to the strong technical skills that were needed to develop the traditional labeling schemes, most of our schemes are almost trivial. The
catch is that in our model, one needs to consult the labels of
*three*vertices instead of two. That is, a query about vertices
uand
vcan access also the label of some third vertex
w(
wis determined by the labels of
uand
v). More generally, we address the model in which a query about vertices
uand
vcan access also the labels of
cother vertices. We term our generalized model
*labeling schemes with queries*.

The main importance of this model is theoretical. Specifically, this paper may serve as a first step towards investigating different tradeoffs between the amount of labels consulted and
the amount of information stored at each vertex. As we show, if all vertices can be consulted then the problem almost reduces to the corresponding sequential problem. On the other hand,
consulting just the labels of
uand
v(or even just the label of
u) reduces the problem to a purely distributed one. Therefore, in a sense, our model spans a range of intermediate notions between the sequential and the distributed settings.

In addition to the theoretical interest, we also show cases that schemes constructed for our model can be translated to the traditional model or to the sequential model, thus, simplifying the construction for those models as well. For implementing query labeling schemes in a distributed environment directly, we point at a potential usage for some new paradigms that became common recently, such as P2P and overlay networks.

An
(
,
)-spanner of a graph
Gis a subgraph
Hthat approximates distances in
Gwithin a multiplicative factor
and an additive error
. More precisely, for any two nodes
u,
vof
G,
d_{H}(
u,
v)
·
d
_{G}(
u,
v) +
. Computing sparse spanners is a fundamental problem of distributed computing
and compact routing.

We also present a second generic deterministic and distributed algorithm based on the construction of small dominating sets and maximal independent sets. After computing such sets in
sub-polynomial time, it constructs at its best a
(1 +
,
)-spanner with
O(
n^{1 + 1/
k})edges, where
. For
k= 3, it provides a
(1 +
, 6-
)-spanner with
O(
^{-1}n^{4/3})edges.

We give distributed algorithms for computing
(1 +
, 1-2
)-remote-spanners for any
>0,
k-connecting
(1, 0)-remote-spanners for any
k1(yielding
(1, 0)-remote-spanners for
k= 1) and 2-connecting
(2, -1)-remote-spanners. All these algorithms run in constant time for any unweighted input graph. The number of edges obtained for
k-connecting
(1, 0)-remote-spanner is within a logarithmic factor from optimal (compared to the best
k-connecting
(1, 0)-remote-spanner of the input graph). Interestingly, sparse
(1, 0)-remote-spanners (i.e. preserving exact distances) with
O(
n^{4/3})edges exist in random unit disk graphs. The number of edges obtained for
(1 +
, 1-2
)-remote-spanners and 2-connecting
(2, -1)-remote-spanners is linear if the input graph is the unit ball graph of a doubling metric (even if distances between nodes are unknown). Our methodology
consists in characterizing remote-spanners as sub-graphs containing the union of small depth tree sub-graphs dominating nearby nodes. This leads to simple local distributed algorithms.

This work gives a theoretical foundation to the OLSR routing protocol (RFC 3626). In particular, it shows that multipoint relays (which are the basis of OLSR functionning) are an inherent structure for providing (1, 0)-remote-spanners, i.e. optimal routes.

Many
*width*graph decompositions have been proposed. Thanks to Courcelle theorem, they allow to efficiently solve many hard (NP-complete) problems for graph classes, provided the
decomposition width is bounded. NLC decomposition is a variation of cliquewidth, where the decomposition is a labelled tree. In
, the recognition of graphs of NLC 2 is addressed. The previous
time complexity is improved to
O(
n^{2}m), and the algorithm is robust.

A new decomposition of combinatorial structures is presented in . Is is based on a generalisation of the modular decomposition. When applied to undirected graph, it gives the bijoin decomposition, and when applied to tournaments, it gives a new decomposition. We present proofs of existence and uniqueness of a decomposition tree, and polynomial-time algorithms.

EnseignantUnivFr[CNRS PRISM, University of Versailles Saint Quentin en Yvelines, France]

Given a
m×
mflow matrix
Fand a
n×
ndistance matrix
D, the Quadratic Assignment Problem (QAP) aims at minimizing the overall energy to carry the flows among the facilities assigned to locations related by the distance matrix; using a
binary assignment
m×
nmatrix
X, its formulation is minimizing:

where
denotes, loosely speaking, the set of permutations. In more standard notations, when
m<
n

Many practical problems give rise to
(
Q
A
P); among special cases, the Traveling Salesperson Problem (TSP) corresponds to
F=
Ithe identity matrix. In order to guess the correlation structure between constraints and objective in 0-1 programming, we devised in
a method to firstly sample the distribution of fractional solutions
of the continuous relaxation and then use this distribution to select an effective branching rule to early detect a
*good solution*; in this sense, it will prune many nodes in the branching tree. Computational results on multiknapsack and the maximum clique problem prove efficiency of this adaptative
approach independent of the given problem. So, it was tempting to experiment this approach to more general integer programming especially those dealing with permutation such as
(
Q
A
P)
,
,
.

MARDI is a collaboration contract between Inria and France Telecom. It gathers Gang and Spontex (FT) around the study of decentralized networks over Internet. Spontex is a transversal project on cooperative networks. Diego Perino is funded through this collaboration and co-supervised by Fabien Mathieu and Laurent Viennot.

A first aspect of the project consist in studying Internet latencies in order to understand how logical overlays can be optimized with respect to delays. A possible track for gathering valuable large scale measures is to use a peer-to-peer network for measuring latencies. Interestingly, it is possible to find shortcuts in the Internet where the route through a relay can be faster than the direct route.

This item is connected to the affinity model where peers tend to connect preferentially to some peers based on some measured or inferred criteria. Connecting peers according to delays is a special case of affinity where a peer connects preferentially to peers with low RTT. Additional properties can be proven for this case to prove the convergence of a dynamic system following this low RTT strategy.

The third part of the project aims at designing efficient structuring algorithm for decentralized applications. It relies on the previous parts. Measuring and modeling Internet latencies can be used to obtain a first coarse solution to a fast overlay, and the affinity models can be use to tune the solution and to adapt it under node churn.

Pierre Fraigniaud is leading an ANR project “blanc” (i.e. fundamental research) about the fundamental aspects of large interaction networks enabling massive distributed storage, efficient decentralized information retrieval, quick inter-user exchanges, and/or rapid information dissemination. The project is mostly oriented towards the design and analysis of algorithms for these (logical) networks, by taking into account proper ties inherent to the underlying infrastructures upon which they are built. The infrastructures and/or overlays considered in this project are selected from different contexts, including communication networks (from Internet to sensor networks), and societal networks (from the Web to P2P networks).

Dynamo is an action of the European COST program (European Cooperation in the Field of Scientific and Technical Research) inside of the Telecommunications, Information Science and Technology domain (TIST). It is leaded by Pierre Fraigniaud (Chair of the managing committee). It gather more than 30 sites all over Europe around Dynamic Communication Networks. The Action is motivated by the need to supply a convincing theoretical framework for the analysis and control of all modern large networks. This will be induced by the interactions between decentralised and evolving computing entities, characterised by their inherently dynamic nature.

Laurent Viennot is a scientific editor of the )i(nterstices ( http://interstices.info/) vulgarization site initiated by Inria in collaboration with french universities and Cnrs. He has written an article on the differences between the web and internet .

Michel Habib is member of the steering committee of STACS (Symposium on Theoretical Aspects of Computer Science) and also of WG (International Workshop on Graph-Theoretic Concepts in Computer Science).

Pierre Fraigniaud has participated to the program committees of:

28th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, Calgary, Canada, August 10-12, 2009.

34th International Symposium on Mathematical Foundations of Computer Science, August 24 - 28, 2009 Novy Smokovec, Slovakia.

36th International Colloquium on Automata, Languages and Programming, Track C "Foundations of Networked Computation", July 5 - 12, 2009 Rhodes, Greece.

17th Annual European Symposium on Algorithms, Sept. 7-9, 2009, Copenhagen.

23rd IEEE International Parallel and Distributed Processing Symposium, Rome, Italy, May 25-29, 2009.

10th International Conference on Distributed Computing and Networking, January 3-6, 2009, Gachibowli, Hyderabad, India.

11th International Symposium on Stabilization, Safety, and Security of Distributed Systems, Lyon, France, November 3-6, 2009.

Michel Habib is in charge of a course entitled “graph algorithms”. Pierre Fraigniaud is in charge of the course “Algorithmique distribuée pour les réseaux”.

Yacine Boufkhad is teaching scientific computer science and networks (192 hours);

Fabien de Montgolfier is teaching foundation of computer science, algorithmics, and computer architecture (192 hours);

Fabien de Montgolfier is teaching P2P theory and application;

Michel Habib is in charge of two courses untitled: Search Engines; Parallelism and mobility, which includes peer-to-peer overlay networks.

Diego Perino
*On Resource allocation algorithms for peer-to-peer multimedia streaming.*(CIFRE Orange Labs). Defended November 16th 2009.

Jury: Advisors (Directeurs): Fabien Mathieu (Orange Labs), Laurent Viennot (INRIA);

Reviewers (Rapporteurs): Marco Ajmone Marsan (Politecnico di Torino), Pascal Felber (Université de Neuchatel), Anne-Marie Kermarrec (INRIA);

Examiners (Examinateurs): Pierre Fraignaud (CNRS), Arnaud Legout (INRIA), Laurent Massoulié, (Thomson Lab).

Damien Noguës:
*Algorithmes pour les graphes
-hyperboliques*(AMN)

Mauricio Soto
*Algorithmes de pair à pair et analyse de la structure d'Internet*(Chile-France Allocation).

Anh Hoang Phan
*Overlays structurés en pair à pair*(BDI).

Hien Hu To
*Décomposition de graphes*(AMX).