@inproceedings {Van2016, title = {A Brief History of MPLS Usage in IPv6}, booktitle = {Passive and Active Measurement Conference (PAM)}, year = {2016}, month = {03/2016}, abstract = {

Recent researches have stated the fast deployment of IPv6. It\ has been demonstrated that IPv6 grows much faster, being so more and more\ adopted by both Internet service providers but also by servers and end-hosts.\ In parallel, researches have been conducted to discover and assess the usage of\ MPLS tunnels. Indeed, recent developments in the ICMP protocol make certain
categories of MPLS tunnels transparent to traceroute probing. However, these\ studies focus only on IPv4, where MPLS is strongly deployed.

In this paper, we provide a first look at how MPLS is used under IPv6\ networks using traceroute data collected by CAIDA.\ We have observed, at the first glance, that the MPLS deployment and usage seem to greatly differ between IPv4 and IPv6,\ in particular in the way MPLS label stacks are used. While label stacks are not that frequent\ in IPv4 (and mostly correspond to a VPN usage), they are prevalent in IPv6. \ However, after a deeper look at the label stack typical content in IPv6, we understand that 2-label stack tunnels are mainly used for dual stack 6PE tunnels and ECMP load sharing purpose. \ The technical deployment of such tunnels is really similar to VPN in practice but the objective is not the same (they are standard tunnels made with the IPv4 LDP for carrying IPv6 traffic).

}, keywords = {6PE tunnels, IPv6, LSE Stack, MPLS}, author = {Yves Vanaubel and Pascal M{\'e}rindol and Jean-Jacques Pansiot and Benoit Donnet} } @inproceedings {Van2015, title = {MPLS Under the Microscope: Revealing Actual Transit Path Diversity}, booktitle = {Internet Measurement Conference (IMC)}, year = {2015}, month = {10/2015}, abstract = {

Traffic Engineering (TE) is one of the keys for improving packet forwarding in\ the Internet. It allows IP network operators to finely tune their forwarding\ paths according to various customer needs. One of the most popular tool\ available today for optimizing the use of networking resources is MPLS. On the\ one hand, operators may use MPLS and label distribution mechanisms such as RSVP-TE\ in conjunction with BGP to define multiple transit paths (for a given edge pair)
verifying different constraints on their network. On the other hand, when\ operators simply enable LDP for distributing MPLS labels in order to improve the\ scalability of their network, another kind of path diversity may appear thanks\ to the ECMP feature of IGP routing.

In this paper, using an MPLS labels analysis, we demonstrate that it is possible\ to better understand the transit path diversity deployed within a given ISP.\ More specifically, we introduce the Label Pattern Recognition (LPR) algorithm, a\ method for analyzing traceroute data including MPLS information. LPR reveals\ the actual usage of MPLS according to the inferred label distribution protocol and\ is able to make the distinction between ECMP and TE multi-path forwarding.\ Based on an extensive and longitudinal traceroute dataset obtained from CAIDA,
we apply LPR and find that each ISP behavior is really specific in regard to its\ MPLS usage. In particular, we are able to observe independently for each ISP\ the MPLS path diversity and usage, and its evolution over time.\ Globally speaking, the main outcomes of our study are that (i) the usage of\ MPLS has been increasing over the the last five years with basic encapsulation\ being predominant, (ii) path diversity is mainly provided thanks to ECMP and\ LDP, and, (iii), TE using MPLS is as common as MPLS without path diversity.

}, keywords = {ECMP, LDP, MPLS, multipath, network discovery, RSVP-TE, traceroute, traffic engineering}, author = {Yves Vanaubel and Pascal M{\'e}rindol and Jean-Jacques Pansiot and Benoit Donnet} } @inproceedings {Van2013a, title = {Network Fingerprinting: TTL-Based Router Signatures}, booktitle = {ACM Internet Measurement Conference (IMC)}, year = {2013}, month = {10/2013}, address = {Barcelona, Spain}, abstract = {

Fingerprinting networking equipment has many potential applications and benefits\ in network management and security. More generally, it is useful for the\ understanding of network structures and their behaviors. In this paper, we\ describe a simple fingerprinting mechanism based on the initial TTL values used\ by routers to reply to various probing messages. We show that main classes\ obtained using this simple mechanism are meaningful to distinguish routers
platforms. Besides, it comes at a very low additional cost compared to standard\ active topology discovery measurements. As a proof of concept, we apply our\ method to gain more insight on the behavior of MPLS routers and to, thus, more\ accurately quantify their visible/invisible deployment.

}, keywords = {fingerprinting, initial TTL, MPLS, network discovery, router signatures}, author = {Yves Vanaubel and Jean-Jacques Pansiot and Pascal M{\'e}rindol and Benoit Donnet} }