Lecture-09 - Lecture#09 Network Layer Objectives...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture #09
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Network Layer Objectives “Best-Effort Delivery End-to-End” Functions robust delivery of packets end-to-end packet routing routing past failures scalability globally unique addressing adherence to layering abstraction (where possible) independent of data link layer hide details from transport layer Protocols Most common example is IP There are others but not worth covering
Image of page 2
Internet Structure: Network of Networks “Tier-2” ISPs: smaller (often regional) ISPs Connect to one or more tier-1 ISPs, possibly other tier-2 ISPs Tier-2 ISP Tier-2 ISP Tier-2 ISP pays tier-1 ISP for Tier-2 ISPs also peer privately with Tier 1 ISP Tier 1 ISP Tier 1 ISP NAP Tier-2 ISP Tier-2 ISP Tier-2 ISP connectivity to rest of Internet boxshadowdwn tier-2 ISP is c ustomer of tier-1 provider each other, interconnect at NAP
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Internet Structure: Network of Networks “Tier-3” ISPs and local ISPs last hop (“access”) network (closest to end systems) Tier-2 ISP Tier-2 ISP local ISP local ISP local ISP local ISP Tier 3 ISP Local and tier- 3 ISPs are Tier 1 ISP Tier 1 ISP Tier 1 ISP NAP Tier-2 ISP Tier-2 ISP Tier-2 ISP local ISP local
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern