Other Data Centers (Microsoft 4) Google Data Center Information. Yahoo Data Center

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1 Chapter 5 Link Layer note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations; and can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) that you mention their source (after all, we d like people to use our book!) If you post any slides on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Thanks and enjoy! JFK/KWR ll material copyright J.F Kurose and K.W. Ross, ll Rights Reserved The course notes are adapted for Bucknell s CSCI 363 Xiannong Meng Spring 214 Computer Networking: Top own pproach 6 th edition Jim Kurose, Keith Ross ddison-wesley March 212 Link Layer 5-1 Link layer, LNs: outline 5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LNs addressing, RP ernet switches VLNS 5.5 link virtualization: MPLS 5.6 data center networking 57a 5.7 day in the life of a web request Link Layer 5-2 Multiprotocol label switching (MPLS) initial goal: high-speed forwarding using fixed length label (instead of address) fast lookup using fixed length identifier (rather than shortest prefix matching) borrowing ideas from Virtual Circuit (VC) approach but datagram still keeps address! PPP or ernet header MPLS header header remainder of link-layer frame MPLS capable s a.k.a. label-switched forward packets to outgoing interface based only on label value (don t inspect address) MPLS forwarding table distinct from forwarding tables flexibility: MPLS forwarding decisions can differ from those of use destination and source addresses to route flows to same destination differently (traffic engineering) re-route flows quickly if link fails: pre-computed backup paths (useful for Vo) label Exp S TTL Link Layer 5-3 Link Layer 5-4 MPLS versus paths routing: path to destination determined by destination address alone R2 R3 Link Layer 5-5 MPLS versus paths entry () can use different MPLS routes to based, e.g., on source address routing: path to destination determined by destination address alone MPLS routing: path to destination can be based on source and dest. address fast reroute: precompute backup routes in case of link failure R2 R3 -only MPLS and Link Layer 5-6 1

2 MPLS signaling modify OSPF, IS-IS link-state flooding protocols to carry info used by MPLS routing, e.g., link bandwidth, amount of reserved link bandwidth entry MPLS uses RSVP-TE signaling protocol to set up MPLS forwarding at downstream s MPLS forwarding tables in out out in out out modified link state flooding RSVP-TE Link Layer R2 in out out 8 6 R3 1 in out R1 out 6 - Link Layer 5-8 Link layer, LNs: outline 5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LNs addressing, RP ernet switches VLNS 5.5 link virtualization: MPLS 5.6 data center networking 57a 5.7 day in the life of a web request Some Statistics bout Google June 26 New York Times reported that Google s alles, Oregan ata Center would create 6 12 fulltime jobs Rate of changes: March 21, serving 7 million web pages with 8, computers In 23, the number of computers grew to 1, The June 26 estimate was 45, scattered over at least 25 locations Jeff ean s presentation anticipates 1 million computers in the next a few years Link Layer Few Other Google ata Centers (1) Belgium ata Center: 341 million dollars 12 long term jobs No chillers, just air cooling, or called free cooling Open early 28 Lenoir, North Carolina ata Center 6 million dollars 15 acres 2 long term jobs Few Other Google ata Centers (2) Goose Creek, South Carolina ata Center 6 million dollars 52 acres 2 jobs

3 Google ata Center Information Estimated that Google has about 36 data centers world wide Google maintains its data center temperature at 8 F Location map of Google data centers nter_map/ Google data center video: Google data center FQ: 15/google data center faq/ Other ata Centers (Microsoft 1) The Chicago ata Center: 7, square feet approximately the size of 16 football fields; Up to 22 shipping containers packed with servers; each container houses 1,8 to 2,5 servers, which makes 396, to 55, servers at the site! Each container can be wheeled in and out of the center in hours and be connected to the internet. nother source said a total capacity of 112 containers holding 224, servers. Go live July 2, Other ata Centers (Microsoft 2) The ublin ata Center (Ireland): 33, square feet, first phase, eventually will reach 55, square feet Supported by megawatts electricity. Go live on July 1, 29. (Started in summer 27.) 5 million dollar project. Expected to create 25 jobs. 15 Other ata Centers (Microsoft 3) The Quincy ata Center (Washington): 47, square feet room on a 75 acre site tile floor and a maze of rooms centering around five 12, square foot brain centers that contain tens of thousands of computer servers. Temperature kept in between 6 and 68 degree Fahrenheit Collects rainwater from its roof to use in its cooling system. Row after row of batteries to kick in for 18 seconds if a power failure should occur before the truck sized backup generators fire up. Go live on March 27, Other ata Centers (Microsoft 4) The San ntonio ata Center (Texas): 55 million dollar project 47, square foot Two 1 megawatt utility feeds, each expandable to 3 megawatts each. Yahoo ata Center Lockport, NY ata Center Using Niagara Fall as its power source 15 million dollars 3 acre site 181, square feet rooms First phase : 1 megawatts of hydro electric power; second phase another 15 megewatts To be completed by May 21 Quincy, Washington Yahoo ata Center

4 ata center networks 1 s to 1 s of thousands of hosts, often closely coupled, in close proximity: e business (e.g. mazon) content servers (e.g., YouTube, kamai, pple, Microsoft) search engines, data mining (e.g., Google) challenges: multiple applications, each serving massive numbers of clients managing/balancing load, avoiding processing, networking, data bottlenecks Inside a 4-ft Microsoft container, Chicago data center 5 19 ata center networks Load balancer Internet C B ccess load balancer: application-layer routing receives external client requests directs workload within data center returns results to external client (hiding data center internals from client) Border Load balancer Tier 1 switches Tier 2 switches TOR switches Server racks Link Layer 5-2 ata center networks rich interconnection among switches, racks: increased throughput between racks (multiple routing paths possible) increased reliability via redundancy Tier 1 switches Tier 2 switches TOR switches Server racks Link layer, LNs: outline 5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LNs addressing, RP ernet switches VLNS 5.5 link virtualization: MPLS 5.6 data center networking 5.7 a day in the life of a web request Link Layer 5-22 Synthesis: a day in the life of a web request day in the life: scenario journey down protocol stack complete! application, transport, network, link putting-it-all-together: synthesis! goal: identify, review, understand protocols (at all layers) involved in seemingly simple scenario: requesting www page scenario: student attaches laptop to campus network, requests/receives browser school network /24 web page Comcast network /13 server web server Google s network /19 Link Layer 5-23 Link Layer

5 day in the life connecting to the Internet day in the life connecting to the Internet (runs ) connecting laptop needs to get its own address, addr of first-hop, addr of server: use request encapsulated in, encapsulated in, encapsulated in 82.3 ernet ernet frame broadcast (dest: FFFFFFFFFFFF) on LN, received at running server ernet demuxed to demuxed, demuxed to (runs ) server formulates CK containing client s address, address of first-hop for client, name & address of server encapsulation at server, frame forwarded (switch learning) through LN, demultiplexing at client client receives CK reply Client now has address, knows name & addr of server, address of its first-hop Link Layer 5-25 Link Layer 5-26 day in the life RP (before, before ) RP query RP RP reply RP (runs ) before sending request, need address of query created, encapsulated in, encapsulated in, encapsulated in. To send frame to, need MC address of interface: RP RP query broadcast, received by, which replies with RP reply giving MC address of interface client now knows MC address of first hop, so can now send frame containing query Link Layer 5-27 day in the life using (runs ) datagram containing query forwarded via LN switch from client to 1 st hop Comcast network /13 server datagram forwarded from campus network into comcast network, routed (tables created by R, OSPF, IS-IS and/or BGP routing protocols) to server demux ed to server server replies to client with address of Link Layer 5-28 day in the life connection carrying day in the life request/reply web page finally (!!!) displayed web server (runs ) to send request, client first opens socket to web server SYN segment (step 1 in 3- way handshake) inter-domain routed to web server web server responds with (step 2 in 3-way handshake) connection established! web server (runs ) request sent into socket datagram containing request routed to web server responds with reply (containing web page) datagram containing reply routed back to client Link Layer 5-29 Link Layer 5-3 5

6 Chapter 5: Summary principles behind data link layer services: error detection, correction sharing a broadcast channel: multiple access link layer addressing instantiation and implementation of various link layer technologies ernet switched LNS, VLNs virtualized networks as a link layer: MPLS synthesis: a day in the life of a web request Chapter 5: let s take a breath journey down protocol stack complete (except PHY) solid understanding of networking principles, practice.. could stop here. but lots of interesting topics! wireless multimedia security network management Link Layer 5-31 Link Layer