The Internet Routing Entropy Monitor is a tool for operators, practitioners, and theoreticians to obtain historic information about the information-theoretical entropy of Internet routing. The entropy closely characterizes the amount of information contained in an Internet routing table, and so it gives a glimpse into the short and long-term scalability and sustainability perspectives of the Internet data plane. The Internet Routing Entropy Monitor provides daily updated statistics from several real IP routers' forwarding tables and makes the raw data freely available for download.

The original intention to create the Internet Routing Entropy Monitor was to verify the seemingly unintuitive finding that the Internet routing ecosystem, shaped by the loosely orchestrated interactions of a huge number of autonomous decision makers, exhibits surprisingly low information-theoretical entropy, indicating that there is a very high level of regularity in Internet routes. This, on the one hand, suggests that routing table compression algorithms have high potential to reduce the memory footprint of routing tables, a key to dispel worrying Internet routing scalability concerns [1], [2]. On the other hand, compelling questions arise regarding the very nature and origin of this vast regularity. It is the hope of the fib_comp team that this service will prove itself useful for the Internet community to answer these fundamental questions.

The main difference from other routing monitoring services, like the University of Oregon Route Views Project, is that in contrast to those services that monitor the Routing Information Base (RIB), the Internet Routing Entropy Monitor analyses the Forwarding Information Base (FIB). Chiefly, the FIB contains correct and timely next-hop distribution (something the RIB, by nature, lacks), which is in turn indispensable to obtain accurate information-theoretical statistics from the Internet data plane.

Currently, the Internet Routing Entropy Monitor keeps track of 20 vantage points located in two remote Autonomous Systems (ASes), the Internet2 (AS 11537) and the HBONE (AS 1955). The IPv4 forwarding tables (FIBs) are downloaded from the vantage point routers on a daily basis, from which 4 FIBs are full-BGP while the rest are smaller FIB instances with internal routes predominantly. Statistics are created and published each day from the collected data.

To make the Internet Routing Entropy Monitor more useful, we need more data from as many routers as possible.

Please, give us your data! Share us your FIBs!

You can offer your FIBs for analysis via filling out the forms below.
Remember: our custom download scripts cause negligible CPU load on your router and the data we offer for download is next-hop-anonymized, making it impossible for others to reconstruct your routing policies.

To understand the statistics published by the Internet Routing Entropy Monitor, you may need to make yourself familiar with some essentials on IP addressing and routing. The below short intro will hopefully prove useful in this. Henceforth, we shall concentrate on IP version 4 exclusively, even though the theory is basically the same for IP version 6 as well.

IP addressing

As of version 4 of IP, hosts, or more precisely, the individual interfaces by which the hosts attach to the Internet are identified by 32 bit numbers, the so called IP addresses. For instance, the IP address of the server that hosts the Internet Routing Entropy Monitor is given as follows in some popular notations:

dotted-decimal	152.66.244.224
32 bit unsigned integer	2554524896
32 bit binary	10011000 01000010 11110100 11100000

Packets traveling on the Internet all carry the IP address of the host they are destined to, which is then used by Internet routers to forward the packets towards the intended destination. To do so, routers maintain a giant database, called the forwarding table, or Forwarding Information Base (FIB), which for each destination address tells to which next-hop router a packet with that address should be forwarded. This way, packets travel from the originating host to the destination host hop-by-hop.

Since there are more than 4 billion IP addresses, it would not be too practical for the FIB to maintain a separate entry for each and every IP address. Internet routing applies a clever trick to sidestep this problem, the Classless Inter-domain Routing (CIDR) scheme. In CIDR, IP hosts are collected, on an administrative or geographical basis, into groups called subnets. Each IP host's address within a subnet begins with the same initial binary prefix, making it possible for the rest of the Internet to refer to any host within the subnet using that prefix. For instance, the server that hosts the Internet Routing Entropy Monitor resides within the BMENET subnet, identified by the following prefix:

dotted-decimal	152.66.0.0/16
32 bit binary	10011000 01000010 00000000 00000000

This essentially means that any host whose IP address begins with the 16 bit binary prefix 10011000 01000010, or matches the wild card 152.66.0.0 on the first 16 bits, resides within BMENET. This facilitates to refer to all the possibly 2¹⁶=65536 hosts within BMENET with a single entry in the forwarding tables of IP routers.

The FIB

Thanks to CIDR, it is enough for Internet routers' forwarding tables to maintain a single entry for each subnet, with the semantics that any packet with a destination address matching the IP prefix of the subnet will be forwarded to the next-hop specified in the forwarding table for that subnet.

Consider the simple excerpt from a real IPv4 FIB:

IP prefix/prefix length	Next-hop address
...
152.61.128.0/18	10.0.0.1
152.66.0.0/16	10.0.0.2
152.66.127.0/24	10.0.0.1
...

The first entry in this FIB segment encodes the forwarding semantics that any packet with a destination address within the prefix 152.61.128.0/18 (i.e., in the range 152.61.128.0 to 152.61.191.255) should be forwarded to the next-hop whose IP address is 10.0.0.1. Furthermore, packets destined to any host within 152.66.0.0/16 take the next-hop router 10.0.0.2. Observe how the clever trick of CIDR hides the uninteresting internal details from the outside, providing just enough information for the rest of the Internet to route route precisely the required packets into the subnet, from where it is the responsibility of the subnet's owner to distribute them to the hosts.

The third entry, however, is a bit peculiar. In particular, it turns out that the prefixes in the second and the third entries overlap. Therefore, for some IP addresses, like for instance 152.66.127.132, there are two matching entries in the FIB, with two distinct next-hop addresses! In such cases, the longest prefix match rule applies, dictating that the entry that matches on the most bits (starting from the most significant bit) takes precedence. Thusly, packets with the IP address 152.66.127.132 will be handled by the third entry as it matches on 24 bits instead of only 16, and hence forwarded to the next-hop 10.0.0.1. The longest prefix match, although increasing the FIB size with introducing such "more-specifics" and also exacerbating FIB lookup substantially, is extremely useful for network operators to fine-tune the way traffic enters their subnet.

Observe that the FIB sample uses private IP addresses (in the prefix 10.0.0.0/8) to encode next-hops. This anonymization is applied to hide the exact internal forwarding policies implemented by the FIB, in order to protect our data sources' privacy. Note, however, that the mapping is consistent in that the same next-hop is always mapped to the same private IP address, and hence next-hop distributions are perfectly maintained. This next-hop anonymization technique is used all over the Internet Routing Entropy Monitor and it is applied for all the FIB data sets available for download.

Prefix trees

Finding the longest matching prefix for a given IP address is not especially easy. One reason is exactly the longest prefix match semantics itself, while the other is that a full-fledged Internet FIB today, CIDR addressing notwithstanding, contains well above 500 thousand entries and counting (see the corresponding charts below). This essentially rules out the naive implementation, one that would search through all the prefixes stored in the FIB one by one, and calls for more sophisticated lookup schemes. The most common FIB data structure is, correspondingly, the prefix tree (or some variant of it).

Consider the FIB sample below.

Prefix in dotted-decimal	Next-hop address	Prefix length	Next-hop
0.0.0.0	0	0	10.0.0.2
64.0.0.0	010	3	10.0.0.1
96.0.0.0	0110	4	10.0.0.2
128.0.0.0	100	3	10.0.0.1
160.0.0.0	1010	4	10.0.0.2
192.0.0.0	1100	4	10.0.0.2
228.0.0.0	111	3	10.0.0.2
244.0.0.0	1111	4	10.0.0.1

The prefix tree corresponding to this FIB takes the following form.

For brevity, in the above figure the next-hop IP addresses are substituted with a single label corresponding to the last byte of the IP address. Also take note of the first entry, 0.0.0.0/0. This prefix matches every IP address, but any other prefix that happens to match the address is more specific. Therefore, this entry is called the "gateway of last resort" (or the default gateway): if no entry matches a packet then forward the packet to the next-hop 10.0.0.2.

Here is how IP address lookup occurs using this prefix tree. Suppose that we are given the IP address 245.124.32.17, whose binary form is 11110101 01111100 00100000 00010001. We take off from the root of the prefix tree (i.e., the topmost node) and we note that this node contains the label corresponding to the next-hop 10.0.0.2. This means that the default gateway matches our IP address, so we immediately have one candidate lookup result. Our task is now to iteratively refine this match until we find the most specific matching entry.\

The iteration starts with taking the first bit of the IP address. In this case the first bit is 1, so we take the right child of the root node along the arc marked by the label 1. Should the first bit be zero, we would have stepped to the left instead of to the right. Since the right child node does not contain a label no new matching FIB entry has been found, so we still go with the default gateway. Next we take the second bit, which is again 1, thus we again take the right exit and we follow this process recursively, traversing the tree downwards until we end up in a node that has no outgoing arc emanating from it marked with the subsequent bit in the IP address (e.g., a leaf node that has no children associated to it at all). In each step, we note the last label we have found along the way as the most specific match. Hence, in the third step we find the node label corresponding to the next-hop 10.0.0.2 (this corresponds to the FIB entry 111/3 -> 10.0.0.2), which is then overridden in the last, fourth step when we find the leaf node with label 1 (FIB entry 1111/4 -> 10.0.0.1). We conclude that the best match is the next-hop 10.0.0.1 and we terminate the process.

What is remarkable in the prefix tree data structure is that the above lookup process is guaranteed to terminate in at most as many steps as there are bits in the IP address (32 for IP version 4, and 128 for version 6), which is way faster than tediously looping through all the FIB entries one by one. Adding a new entry, or deleting or modifying an existing one, goes in the same number of steps, making prefix trees extremely appealing for storing the forwarding table in IP routers.

An information-theoretic view on IP FIBs

There has been an ongoing research effort for many years to reduce the memory footprint of the above prefix tree data structure (or improve the lookup speed further, for that matter). Easily, the smaller the FIB the more entries can be squeezed into the limited memory of IP routers, letting the Internet to scale to ever-more users and end-hosts. As such, the information content of the FIB tells an interesting story about the long-term scalability perspectives of the Internet architecture. If the memory footprint were large, or it were to skyrocket with every new prefix added, then this would cast a very dark shadow over the future of the Internet, essentially inhibiting it from scaling beyond a certain limit. The main purpose of creating the Internet Routing Entropy Monitor was to answer these fundamental questions by observing the information content of several real IP routers around the globe.

What remained to be done is to somehow define a metric that would characterize the information content of a forwarding table. This metric is loosely referred to as entropy in information-theory. Below, we attempt to define the FIB entropy in layman's terms. For more in-depth coverage, consult the papers [1], [2].

The leaf-pushed prefix tree

The first problem we face is that there are many equivalent ways to describe the same forwarding semantics using prefix trees. That is, a prefix tree can take many equivalent forms, each defining exactly the same packet forwarding rules, and it is not especially easy to decide which one to choose to derive FIB entropy from. For instance, the below prefix tree is easily seen to associate the exact same next-hop to each fully-specified IP address as the original one, yet it is substantially smaller.

The trick here is that we are free to play around with more specifics, opening the door to an assortment of semantically equivalent prefix tree representations with highly different structure. What we need is a "normalized" form for FIBs of some sort, one that would be the same for each and every semantically equivalent FIB. Such a normalized form is the binary leaf-pushed prefix tree.

The idea is that we eliminate all less-specifics from the FIB, essentially transforming the forwarding table into a minimal prefix-free form. Consider the below leaf-pushed prefix tree for our running example.

One easily checks that, on the one hand, this form associates the exact same next-hop to each address as the original one and, on the other hand, the corresponding forwarding table (see below) has the property that no entry is the prefix of another entry. It can be proved that, thanks to the prefix-free property, the leaf-pushed prefix tree representation of the FIB is unique, providing an excellent basis to derive FIB entropy from.

Prefix in dotted-decimal	Next-hop address	Prefix length	Next-hop
0.0.0.0	00	2	10.0.0.2
64.0.0.0	010	3	10.0.0.1
96.0.0.0	011	3	10.0.0.2
128.0.0.0	100	3	10.0.0.1
160.0.0.0	101	3	10.0.0.2
192.0.0.0	110	3	10.0.0.2
228.0.0.0	1110	4	10.0.0.2
244.0.0.0	1111	4	10.0.0.1

The information-theoretic lower-bound

From this point, we are ready to cast the task to define the FIB entropy notion using information-theoretical arguments. Let \(\Sigma\) denote the set of next-hop IP addresses in the FIB, let \(n\) denote the number of leaf nodes in the leaf-pushed tree, and let \(n_i\) denote the number of times next-hop \(i \in \Sigma\) appears as a label for a leaf node in the leaf-pushed tree. Using this notation, the relative frequency of next-hop \(i \in \Sigma\) appearing in the leaf-pushed tree is \(p_i = \frac{n_i}{n}\).

The first notion of information content, called the information-theoretic lower-bound, roughly corresponds to the number bits needed to assign for each instance of leaf-pushed trees on \(n\) leaves a unique identifier and using that identifier to refer to the FIB. In the case of IP FIBs, the empirical information-theoretic lower bound is \(2n + n \log_2 |\Sigma|\) bits, where \(n\) and \(\Sigma\) are as above. The (very simplified) explanation is that we need at most \(2n\) bits to differentiate between any two unlabeled binary trees on \(n\) leaves, to which the size of the string comprised by the next-hop addresses written to the leaf nodes adds another \(n \log_2 |\Sigma|\) bits. Note, however, that this simple formula provides only an approximation to the information-theoretic lower-bound, which is, unfortunately, extremely difficult to quantify precisely [1]. In fact, the real metric is somewhat smaller, but the above estimate still proves very useful in practice.

FIB entropy

The information-theoretic lower bound gives an estimate of the information content of the FIB in the case when we know nothing about its internals, i.e., if we took the FIB as essentially random. However, very often we have more knowledge from a forwarding table and we can make use of this insight to compress the FIB to below the information-theoretic lower bound.

For instance, we could make some statistics about the distribution of next-hop labels in the leaf-pushed tree and then we could use the standard trick of data compression to encode popular next-hops on only a few bits and less popular ones on more bits. This way, whenever we encounter a popular label we use fewer bits than a naive encoder would do, which greatly compensates for the bits we waste when encoding less popular next-hops. This is the idea behind many data compression schemes, and this is also the way we associate an entropy measure to IP FIBs.

Define the empirical Shannon-entropy of the next-hop distribution in the leaf-pushed tree as usual:

\begin{equation*} H_0 = \sum_{i\in\Sigma} p_i \log_2\left( \frac1{p_i} \right) \enspace . \end{equation*}

Note that the entropy of the next-hop distribution is guaranteed to be smaller than the information-theoretic lower bound, that is, \(H_0 \le \log_2 |\Sigma|\), with equality if and only if the next-hop distribution \(p_i: i \in \Sigma\) is uniform. Hence, any encoder that attains the entropy is guaranteed to compress below information-theoretic lower bound, unless the input data is completely random.

Using this notation, the empirical FIB entropy bound is \(2n + n H_0\) bits, where again \(n\) is the number of leaf nodes in the normalized (leaf-pushed) prefix tree for the FIB and \(p_i\) describes the relative frequency of next-hop \(i \in \Sigma\) appearing as a next-hop label on the leaves. The explanation in layman's terms is that we need roughly \(2n\) bits to encode the tree, to which the next-hop string written to the leaves gives an extra \(n H_0\) bits. Again, this is only a very simple conservative estimate of the real-entropy (which would otherwise be next to impossible to compute precisely), but even this crude estimate is already very useful in practice.

What the FIB entropy is NOT

Above all, it is not a metric on compressibility. Or it is possible that it actually is, but so far no one has actually proved this.

Let us dig a bit deeper. In standard information-theory, a very important theoretical property of the entropy bound is that it gives a good estimate on the minimum number of bits needed to encode whatever data. For sequential data (like a string), it is well-known that the entropy bound of \(nH_0\) bits provides an absolute limit on the best possible lossless compression of that data (at least, with a zero-order encoder). Unfortunately, this argumentation does not quite bring over to IP FIBs, or at least we still do not know whether it does. The reasons are multiple. First, even the entropy bound of \(2n + n H_0\) bits is already a (conservative) approximation and the real entropy bound should be somewhat smaller. Second, we still do not know whether or not the leaf-pushed prefix tree is a minimal data structure to encode the subnetting hierarchy inherent to the IP address space, and it can very well happen that other representations yield smaller entropy bounds.

What the FIB entropy is

Still, the notion of FIB entropy presents a unique opportunity to look into the very knowledge encoded in the Internet data plane, as described below.

• Regularity: The FIB entropy bound of \(2n + n H_0\) bits is shaped by two essential factors, namely, the number of leaves \(n\) of the leaf-pushed tree and the Shannon-entropy \(H_0\) of the next-hop distribution. Interestingly, there is an intricate interdependence between these two factors. Imagine two FIBs containing identical number of entries, one FIB with a dominant next-hop carrying most of the prefixes and the other FIB with roughly uniform next-hop distribution. The first FIB's next-hop distribution will be very biased (i.e., highly regular), reducing the leaf-pushed tree size \(n\) and/or the Shannon-entropy \(H_0\), leading to a small entropy bound. The other FIB, however, is of maximal entropy, and thusly cannot be substantially compressed beyond the information-theoretic minimum. The Shannon-entropy of the next-hop distribution is therefore a very good indicator of the regularity hidden deep within the seemingly complex forwarding rules implemented by an IP router. It must be noted, though, that the entropy \(H_0\) should always be viewed side-by-side with the size parameter \(n\), or the entropy bound \(2n + n H_0\), as in itself neither is decisive.
• Routing policies: The Shannon-entropy of an IP FIB presents a bird's-eye view of the routing policy as implemented by an Internet router. If the entropy is small then the next-hop distribution is highly biased, indicating the presence of a dominating next-hop, say, a default route or a primary provider. Interestingly, most of the FIBs we collect from vantage points are of this type. If, on the other hand, the entropy is large, say, close to the information-theoretic limit \(H_0 \approx \log_2 |\Sigma|\), then each next-hop is likely to appear with equal probability for any prefix. So far we have not seen any FIB of this type, but we know theoretically that they should arise in reality. For instance, we would expect such FIBs to show up at Internet eXchange Points (IXPs).
• Space upper bound: Even though not a lower bound on the amount of bits needed to encode a FIB, the FIB entropy is still a very useful upper-bound on the space requirements thereof, in that there are actual FIB compressors that attain the \(2n + n H_0\) bits storage space limit in practice [1], [2]. That means that we never need more bits than the entropy bound (subject to smaller order error terms), while we may very well get on with fewer bits in some cases.
• Information content: It turns out that the entropy bound gives an appealing way to characterize the amount of information present in the FIB. The entropy bound of \(2n + n H_0\) bits simply means that a FIB contains (at most) an equivalent of answering precisely \(2n + n H_0\) yes-or-no questions. Easily, the latter is possible by storing \(2n + n H_0\) bits, each one specifying the answer to one of the questions (say, 0 would mean no and 1 would mean yes), and this simple argumentation supplies a universal scheme to measure the information content encoded in an IP FIB.
• Complexity: The above universal interpretation of FIB information content allows us to compare the complexity (in terms of the amount of information stored) of an IP FIB to essentially any other data. For instance, we see that a full-fledged IP FIB, containing more than 500,000 entries, stores roughly 150-200 KBytes of information. This is equivalent to a larger email message, a smaller PDF document, a low resolution photo image, or roughly 600,000 characters of English text (the equivalent of a small novel). And it is way smaller than any computer encoded music file, photo of reasonable resolution, or most of the executable files on your PC for that matter. It seems that IP packet forwarding is not that difficult after all, despite that we are talking about a world-wide network infrastructure connecting billions of hosts!
• Evolution: The evolution of FIB entropy, being a metric of information complexity for IP forwarding, gives us a glimpse into the very sustainability of Internet routing. It seems that the entropy has been fairly constant throughout the last few months, or it has changed very little over time. It would be tempting to arrive to the reassuring conclusion that the long-term scalability perspectives of the Internet routing ecosystem are pretty rosy. Nevertheless, it must be mentioned that the sample size and the time frame described in the statistics do not allow to make overall conclusions. For this, we would need much more data!
• Faster lookups: As it turns out, not just that the entropy gives a crude upper bound on the number of bits we can compress an IP FIB down to and that this bound is in fact attainable by real life FIB encoders, but this comes without sacrificing lookup performance is any ways whatsoever [1]! In fact, IP lookups on the compressed form are usually much faster than on the uncompressed one, due to the improved cache-friendliness caused by smaller memory footprint. This holds a great potential for IP FIB compression.

Statistics

Here is a short recap on the most important statistics published at the Internet Routing Entropy Monitor. Click here for more background on the data.

• Entropy (\(H_0\), [bits]): The Shannon-entropy of the next-hop distribution on the leaf-pushed prefix tree. To obtain it, the raw FIB is converted into a normalized leaf-pushed prefix tree and then the Shannon-entropy of the resultant leaf-label distribution is computed.
• Number of raw FIB entries: The number of entries in the original FIB, as downloaded from the vantage point routers. Should be in the range of several hundred thousands for full-BGP FIBs and several thousands for FIB instances with a default gateway.
• Entropy bound (\(2n + nH_0\), [Kbytes]): The entropy bound derived from the leaf-pushed prefix tree representation of the FIB. The raw FIB is converted into a normalized leaf-pushed prefix tree form and then the entropy bound is computed from the number of leaf nodes \(n\) within this form and \(H_0\), the Shannon-entropy as above.
• Number of next-hops: As the name suggests, the number of individual next-hop IP addresses as appearing in the FIB.
• Next-hop CDF: The cumulative distribution function of next-hop label distribution within the FIB. The FIB is first converted into a normalized leaf-pushed form and the relative frequency of each next-hop address is calculated. For this, the number of times \(n_i\) for each next-hop \(i \in \Sigma\) appearing in the leaf-pushed prefix tree as a leaf label is computed. Then, next-hops are arranged into an ascending order of popularity and the cumulative distribution function is depicted on a log-log scale that for each next-hop gives how many times this next-hop and all the less popular next-hops appear in the FIB.

The below diagrams give a glimpse into the data collected from each vantage point. For the statistics on individual vantage points, click here. All the diagrams are freely clickable. To magnify a region, draw a rectangle on the diagram. Click the right mouse button to reset to the time series. Click here for some background on these statistics and here for an explanation of the parameters given in the diagrams.

Entropy (\(H_0\))

Number of raw FIB entries

FIB name	Source	Last update	#Entries	#Next-hops	Entropy	Size (KB)
Atlanta	Internet2	2024-11-30	0	0	0.0	0.0
Chicago	Internet2	2024-11-30	0	0	0.0	0.0
Cleveland	Internet2	2024-11-30	0	0	0.0	0.0
Houston	Internet2	2024-11-30	0	0	0.0	0.0
KansasCity	Internet2	2024-11-30	0	0	0.0	0.0
LosAngeles	Internet2	2024-11-30	0	0	0.0	0.0
NewYork	Internet2	2024-11-30	0	0	0.0	0.0
SaltLakeCity	Internet2	2024-11-30	0	0	0.0	0.0
Seattle	Internet2	2024-11-30	0	0	0.0	0.0
Washington	Internet2	2024-11-30	0	0	0.0	0.0
hbone_bme	HBONE	2024-11-30	960079	1	0.0	0.0
hbone_debrecen	HBONE	2024-11-30	2264	1	0.0	0.0
hbone_miskolc	HBONE	2024-11-30	2311	1	0.0	0.0
hbone_pecs	HBONE	2024-11-30	2247	1	0.0	0.0
hbone_sopron	HBONE	2024-11-30	2241	1	0.0	0.0
hbone_szeged	HBONE	2024-11-30	960179	1	0.0	0.0
hbone_szolnok	HBONE	2015-12-15	1971	88	3.297515	2.82
hbone_veszprem	HBONE	2024-11-30	2163	1	0.0	0.0
hbone_vh1	HBONE	2024-11-30	960036	270	2.573208	344.12
hbone_vh2	HBONE	2024-11-30	960070	136	1.572717	224.76

If you need access to the next-hop anonymized data, please send an email to fib_comp [at] lendulet.tmit.bme.hu.

The fib_comp team would like to thank for the Internet2, the NIIF HBONE for making their data available for analysis. Special thanks go to Levente Csikor for creating and maintaining the website.

The members of the fib_comp team:

• Gábor Rétvári
• Attila Kőrösi
• János Tapolcai
• Levente Csikor
• Bence Mihálka

[1]	Gábor Rétvári, János Tapolcai, Attila Kőrösi, András Majdán, and Zalán Heszberger. Compressing IP forwarding tables: towards entropy bounds and beyond. In ACM SIGCOMM 2013, pages 111-122, 2013. [ bib | DOI | slides | paper ]
[2]	Gábor Rétvári, Zoltán Csernátony, Attila Kőrösi, János Tapolcai, András Császár, Gábor Enyedi, and Gergely Pongrácz. Compressing IP forwarding tables for fun and profit. In Eleventh ACM Workshop on Hot Topics in Networks (HotNets-XI). ACM, October 2012. [ bib | slides | paper ]

We are greatly thankful for your help. the fib_comp team