CSC458H1 Lecture Notes - Lecture 5: Global Crossing, Réseaux Ip Européens Network Coordination Centre, Border Gateway Protocol
Document Summary
Internet topology: internet routing architecture divided into autonomous systems (as, 1 as = controlled by single instituation Manages routers/links in that region of internet. Isp, companies, universities, etc: as uses 16-bit identifier 52k of 65k in use. Level 3 = 1; mit = 3; uoft = 239; at&t = 7018, 6341, 5074, . Some has multiple as nodes b/c geographies: as hierarchy. Large tier-1 providers w/ nationwide backbone. Small single company/university networks: as topology, example: princeton. Customer to providers at&t and uslec for internet. Customer to provider internet2 for research universities/labs. Peers w/ patriot media: as structure, tier-1 providers no upstream providers; 10 to 20 as. High connectivity full peer-peer connections amongst themselves. Uunet, sprint, at&t, level 3, etc : node = autononmous system, edge = two connected as, Two connected as"s has one or more links. Destinations can be reached from one as via the other: tier-2 providers atleast 1 provider upstream (tier 1); 1000s as.
