18c - Router Design - Lookup Problem

18c - Router Design - Lookup Problem - Last Lecture Network...

Info icon This preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Last Lecture: Network Layer 1. Design goals and issues 2. Basic Routing Algorithms & Protocols 3. Addressing, Fragmentation and reassembly 4. Internet Routing Protocols and Inter-networking 5. Router design 1. Short History + Router Architectures 2. Switching fabrics 3. Address lookup problem 6. Congestion Control, Quality of Service 7. More on the Internet’s Network Layer SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 1
Image of page 1

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

View Full Document Right Arrow Icon
Last Lecture: Network Layer 1. Design goals and issues 2. Basic Routing Algorithms & Protocols 3. Addressing, Fragmentation and reassembly 4. Internet Routing Protocols and Inter-networking 5. Router design 1. Short History + Router Architectures 2. Switching fabrics 3. Address lookup problem 6. Congestion Control, Quality of Service 7. More on the Internet’s Network Layer SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 2
Image of page 2
Reminder on Router Architecture Lookup IP Address Update Header Header Processing Data Hdr Data Hdr ~1M prefixes Off-chip DRAM Address Table IP Address Next Hop Queue Packet Buffer Memory ~1M packets Off-chip DRAM SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 3
Image of page 3

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

View Full Document Right Arrow Icon
Basic Requirements 1) Fast lookup and fast update 2) Scalable (speed & table size) 3) Inexpensive (fit in memory, e.g.) SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 4
Image of page 4
Lookups Must Be Fast 1. Lookup mechanism must be simple and easy to implement 2. Memory access time is the bottleneck 200Mpps × 2 lookups/pkt = 400 Mlookups/sec 2.5ns per lookup Year Aggregate Line- rate Arriving rate of 40B POS packets (Million pkts/ sec) 1997 622 Mb/s 1.56 1999 2.5 Gb/s 6.25 2001 10 Gb/s 25 2003 40 Gb/s 100 2006 80 Gb/s 200 SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 5
Image of page 5

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

View Full Document Right Arrow Icon
Memory Technologies (2006) Note: rough estimates only. Manufacturer & technology & market dependent Technology Max single chip density $/chip ($/MByte) Access speed Watts/ chip Networking DRAM 64 MB $30-$50 ($0.50-$0.75) 40-80ns 0.5-2W SRAM 8 MB $50-$60 ($5-$8) 3-4ns 2-3W TCAM 2 MB $200-$250 ($100-$125) 4-8ns 15-30W SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 6
Image of page 6
(Ternary) Content Addressable Memory SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 7
Image of page 7

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

View Full Document Right Arrow Icon
Lookup Problem: Protocol Dependent Networking Protocol Lookup Mechanism Techniques we will study MPLS, ATM (virtual circuits) Ethernet 1. Exact match search – Direct lookup – Associative lookup – Hashing – Binary/Multi-way Search Trie/ Tree IPv4, IPv6 (datagram) 2. Longest- prefix match search -Radix trie and variants -Compressed trie -Binary search on prefix intervals SUNY at Buffalo; CSE 489/589 – Modern Networking Concepts; Fall 2010; Instructor: Hung Q. Ngo 8
Image of page 8
1. Exact Match – Virtual Circuit Reminder
Image of page 9

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

View Full Document Right Arrow Icon
Image of page 10
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