FIDEMO 2009, Nov. 18

1. FIDEMO 2009, Nov. 18 :A: :B: A Step Towards a Planet-scale Measurements Retrieval Infrastructure B::A ... http://an.kaist.ac.kr/projects/sibilla X Y Abstract A Source AS Intermediate ASes ... Destination AS Z W X::A::W = ? Rule #1, 2, 3 Rule #1, 2, 3 In this work, we propose to design an end-to-end path and delay estimation service, called Sibilla*. We envision a DNS-like system where applications send queries and receive information on desired metrics, without doing measurements by themselves. The novelty of our system is that we utilize existing measurements and an infrastructure. Our delay estimation is based on a simple idea of path stitching. To provide the path-stitching as a service, we design and deploy our estimation service system on top of the Domain Name System (DNS). We deploy a Sibilla DNS server that receives a query between two hosts and replies with an estimated delay through the DNS interface. We take advantage of the fact that local DNS cache servers are distributed globally and exist in almost all ASes and improve the accuracy of our path stitching algorithm. *Sibilla is a female oracle figures in Greek and Roman times, offering cryptic predictions to those who sought to know the future (Sybil in English) Path-Stitching Algorithm Query interface Path and delay estimation between any pair of Internet hosts Key assumption: “Many good measurement data are available already.” Decoupling the data collection phase from the data analysis Key Ideas behind path stitching: Internet separates inter- and intra-domain routing; To predict a new path: » Splits paths into AS-level path segments, and » Stitches path segments together » Using BGP routing information Internet path? delay? ac End-to-end delay graphs are generated on-the-fly Step 1. IP-to-AS mapping aA Cc Step 2. AS path inference Path stitching aA Cc B Authoritative Name Server (Supporting sibilla.com and all sub-domains) Step 3. Path stitching Display statistics of stitched paths :A: :B: :C: 1 2 3 4 A::B B::C Stitched paths are displayed and animated on the Google Map DNS response :A::B::C: DNS query (srcIP_dstIP.latency.sibilla.com) Local Name Server Step 4. Rank stitched paths and select the best • Missing AS: • No solutions (other than collecting more data) • Missing inter-domain segments: • Search for reverse path segments • Path segments that do not rendezvous • at the same address • Use clustering heuristics Query Rule #1: Proximity Rule #2: Destination-bound path segments Rule #3: Most recent path segments Reply “An easy interface to a new system is the key demo-site sibilla prototype Sibilla Internet Users in the system’s success.” BGP routing table snapshots Data contribution RouteViews and RIPE Traceroute outputs (IPv4 Routed /24 topology data set) System Interface Demo Scenario Too Many Segments: Preference Rules No Segments: Approximations CAIDA Ark project Contributors The basic idea of our service system is to formulate a delay query between two hosts as a DNS query and let our Sibilla DNS server answer it. For example, when a user wants to estimate delay between two points A and B, the user submits a DNS query for A_B.latency.sibilla.com. The local DNS server forwards the query to our Sibilla DNS server, which in turn replies with delay estimation. Conclusion The beauty of our system lies in the simplicity of the service system design. Any improvement of the path-stitching algorithm in terms of added measurements and better estimation method can be immediately reflected in a deployed system, as the DNS interface cleanly separates the user interface and the estimation mechanism. To change our system from the current off-line version to serve thousands of queries a second, we plan to profile our algorithm and employ appropriate accelerating measures. Demo setup Future Internet Technology Demonstration/Exhibition, November 18, 2009 Advanced Networking Laboratory, KAIST