internet infrastructure and access henning schulzrinne dept. of computer science columbia university...
TRANSCRIPT
![Page 1: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/1.jpg)
Internet infrastructure and access
Henning Schulzrinne
Dept. of Computer Science
Columbia University
Fall 2003
![Page 2: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/2.jpg)
Internet backbones
Classify ISPs into tiers– tier 1: global reach, about 40
British Telecom (BT), Cable & Wireless, Global Crossing, Level 3, Sprint, MCI (UUnet), Verio (NTT), …
– tier 2: regional– tier 3: local
Tier-1’s typically use railroad tracks or pipelines as right-of-way
– some also lease (some) circuits from other providers– at least 20,000 fiber miles
Connect to local circuits via points-of-presence (POP)
![Page 3: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/3.jpg)
Internet backbones
OC-3 (155 Mb/s), OC-12 (622 Mb/s), OC-48 (2.4 Gb/s) or OC-192 (10 Gb/s)
Usually, WDM or D-WDM (e.g., 16 λ x 2.5 Gb/s, up to 40 λ)
– 50 or 100 GHz optical spacing Fiber: about $30,000-$50,000/mile, almost all
construction Transport: POS (packet over SONET), MPLS, ATM,
FR (edges) Backbone utilization: no more than 30% typical
– needed for fault recovery
![Page 4: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/4.jpg)
Network utilization
local phone line: 4% U.S. long distance switched voice: 33% Internet backbones: 10-15% private line networks: 3-5% LANs: 1%
![Page 5: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/5.jpg)
ISPs
America Online dial 25.3
MSN dial 8.7
United Online (Juno) dial 5.2
Earthlink dial 5.0
Comcast cable 4.4
SBC DSL 2.8
Verizon DSL 1.9
Cox cable 1.7
Charter cable 1.3
BellSouth DSL 1.2
Many dial-up ISPs don’t own modems use wholesale providers
DSL + cable modem modems are always
oversubscribed (10:1?)
![Page 6: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/6.jpg)
Residential broadband
![Page 7: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/7.jpg)
Quick review: DSL
Uses spectrum from 25 kHz to 1.1 MHz ATM cells Ethernet PPP DSLAM aggregates circuits US local loops can be up to 18 kft long ADSL+: 16 Mb/s @ 4 kft, 10 Mb/s @ 6 kft
(1.1 mi) downstream
![Page 8: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/8.jpg)
Commercial international backbone
![Page 9: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/9.jpg)
Internet2 backbone (Abilene)
![Page 10: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/10.jpg)
Internet2 (Abilene) 10 Gb/s network
![Page 11: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/11.jpg)
Peering
Exchange of traffic between ISPs– autonomous systems (AS)– private peering vs. public peering– public peering at MAE-East, MAE-West, AMS-IX, …– either a LAN or mesh of ATM/FR VCs
Sender keeps all (SKA) = only pay for rack space, not traffic
Alternative: transit payment (tier2 tier1)
![Page 12: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/12.jpg)
Peering points: AMSIX in Amsterdam
![Page 13: Internet infrastructure and access Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003](https://reader035.vdocuments.site/reader035/viewer/2022070306/5516a1d5550346f6208b4cb7/html5/thumbnails/13.jpg)
Peering point: AMSIX