The many facets of internet topology and traffic

Abstract

The Internet's layered architecture and organizationalstructure give rise to a number of different topologies,with the lower layers defining morephysical and the higher layers more virtual/logical types ofconnectivity structures. These structures are very different,and successful Internet topology modeling requires annotatingthe nodes and edges of the corresponding graphs withinformation that reflects their network-intrinsic meaning.These structures also give rise to different representationsof the traffic that traverses the heterogeneous Internet, anda traffic matrix is a compact and succinct description of thetraffic exchanges between the nodes in a given connectivitystructure. In this paper, we summarize recent advances inInternet research related to (i) inferring and modeling therouter-level topologies of individual service providers (i.e.,the physical connectivity structure of an ISP, where nodesare routers/switches and links represent physical connections),(ii) estimating the intra-AS traffic matrix when the AS'srouter-level topology and routing configuration are known,(iii) inferring and modeling the Internet's AS-level topology,and (iv) estimating the inter-AS traffic matrix. We will alsodiscuss recent work on Internet connectivity structures thatarise at the higher layers in the TCP/IP protocol stack and aremore virtual and dynamic; e.g., overlay networks like the WWWgraph, where nodes are web pages and edges represent existinghyperlinks, or P2P networks like Gnutella, where nodes representpeers and two peers are connected if they have an active networkconnection.