Categories
Papers Publications

New paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” at IFIP TMA 2020

We published a new paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” by Lan Wei (University of Southern California/ ISI), Marcel Flores (Verizon Digital Media Services), Harkeerat Bedi (Verizon Digital Media Services), John Heidemann (University of Southern California/ ISI) at Network Traffic Measurement and Analysis Conference 2020.

From the abstract:

IP anycast is widely used today in Content Delivery Networks (CDNs) and for Domain Name System (DNS) to provide efficient service to clients from multiple physical points-of-presence (PoPs). Anycast depends on BGP routing to map users to PoPs, so anycast efficiency depends on both the CDN operator and the routing policies of other ISPs. Detecting and diagnosing
inefficiency is challenging in this distributed environment. We propose Bidirectional Anycast/Unicast Probing (BAUP), a new approach that detects anycast routing problems by comparing anycast and unicast latencies. BAUP measures latency to help us identify problems experienced by clients, triggering traceroutes to localize the cause and suggest opportunities for improvement. Evaluating BAUP on a large, commercial CDN, we show that problems happens to 1.59% of observers, and we find multiple opportunities to improve service. Prompted by our work, the CDN changed peering policy and was able to significantly reduce latency, cutting median latency in half (40 ms to 16 ms) for regions with more than 100k users.

The data from this paper is publicly available from RIPE Atlas, please see paper reference for measurement IDs.

Categories
Announcements Projects

new project “Plannning for Anycast as Anti-DDoS” (PAADDoS)

We are happy to announce a new project Plannning for Anycast as Anti-DDoS (PAADDoS).

The PAADDoS project’s goal is to defend against large-scale DDoS attacks by making anycast-based capacity more effective than it is today.

We will work toward this goal by (1) developing tools to map anycast catchments and baseline load, (2) develop methods to plan changes and their effects on catchments, (3) develop tools to estimate attack load and assist anycast reconfiguration during an attack. and (4) evaluate and integration of these tools with traditional DoS defenses.

We expect these innovations to improve service resilience in the face of DDoS attacks. Our tools will improve anycast agility during an attack, allowing capacity to be used effectively.

PAADDoS is a joint effort of the ANT Lab involving USC/ISI (PI: John Heidemann) and the Design and Analysis of Communication Systems group at the University of Twente (PI: Aiko Pras).

PAADDoS is supported by the DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I, and by NWO.