Mapping peering interconnections to a facility

Abstract

Annotating Internet interconnections with robust physical coordinates at the level of a building facilitates network management including interdomain troubleshooting, but also has practical value for helping to locate points of attacks, congestion, or instability on the Internet. But, like most other aspects of Internet interconnection, its geophysical locus is generally not public; the facility used for a given link must be inferred to construct a macroscopic map of peering. We develop a methodology, called constrained facility search, to infer the physical interconnection facility where an interconnection occurs among all possible candidates. We rely on publicly available data about the presence of networks at different facilities, and execute traceroute measurements from more than 8,500 available measurement servers scattered around the world to identify the technical approach used to establish an interconnection. A key insight of our method is that inference of the technical approach for an interconnection sufficiently constrains the number of candidate facilities such that it is often possible to identify the specific facility where a given interconnection occurs. Validation via private communication with operators confirms the accuracy of our method, which outperforms heuristics based on naming schemes and IP geolocation. Our study also reveals the multiple roles that routers play at interconnection facilities; in many cases the same router implements both private interconnections and public peerings, in some cases via multiple Internet exchange points. Our study also sheds light on peering engineering strategies used by different types of networks around the globe.

traIXroute: Detecting IXPs in traceroute paths

“…Recently, Giotsas et al [19] introduced techniques to identify the physical facility where ASes interconnect using targeted traceroute measurements and a combination of publicly available facility and IXP based information.…”

Detecting Peering Infrastructure Outages in the Wild

“…Direct peering is enabled by third party peering infrastructures (also referred as carrier-neutral peering infrastructures), such as colocation facilities and Internet Exchange Points (IXPs). These infrastructures are increasingly deployed in cities around the globe [50], and their members are growing constantly [61,68] supporting hundreds of thousands of peerings [100].…”

“…While a map of the U.S. long-haul fiber-optic infrastructure including some of the carrier facilities of major U.S. ISPs was released last year [34], we lack a detailed map of peering infrastructures. Two recent works attempt to tackle this problem by using large-scale active traceroute campaigns to infer the IP-level connectivity at colocation facilities [50,72]. However, these methods scale only for a limited number of ASes or a limited number of facilities.…”

“…Facilities are mainly concentrated in metropolitan areas, with major telecommunication hubs like London and New York hosting dozens of facilities [50]. While it is common practice among facility operators not to publish the number of PNIs, there are indications that their number is continuously growing.…”

“…With the advent of Content Distribution Networks (CDNs) and the placement of data caches close to the users, the interconnection landscape has become increasingly clustered in large metropolitan hubs [50,70]. The geographic agglomeration of the peering activity has led to an increasingly symbiotic relationship between IXPs and colocation facilities: IXPs benefit from placing their switches in locations where ISPs can easily install their network equipment, while facility operators often subsidize the presence of IXPs in their space to increase the attractiveness of their colocation ecosystem [12,78].…”