Challenges Deploying a Global Network Holly Brackett Pease Director, Network Engineering

1. Challenges Deploying a Global NetworkHolly Brackett PeaseDirector, Network Engineering Digital Island Holly Brackett Pease USENIX NETA‘99

2. Challenges Deploying A Global Network • The Digital Island Solution • A Brief Overview of BGP • Challenges of Worldwide Routing • Ensuring Routes Are Accepted • Tier-1 Provider Policies • BGP Limitations • Logistics of Deploying a Global Environment Holly Brackett Pease USENIX NETA‘99

3. Audience • Network Managers Homed to Multiple Internet Service Providers • Network Managers building a Global Network • Network Managers with International Internet Connectivity • General Interest in Internet Routing Holly Brackett Pease USENIX NETA‘99

4. The Digital Island Problem • Internet: A Collection of Autonomous Networks • US-Centric Internet • In some regions of the world, country-country traffic passes through the US • Congested Internet Exchanges and NAPs • Increased Demand for International Access Holly Brackett Pease USENIX NETA‘99

5. The Digital Island Solution • A Private Global Network Built to Deliver QOS • Bypasses Congested NAPs and Exchange Points • One Hop to the World Holly Brackett Pease USENIX NETA‘99

6. The Digital Island Strategy • Private Backbone • Geographic-based Routing • Peer with Tier-1 International Partners • Partners distribute routes in-country Holly Brackett Pease USENIX NETA‘99

7. A Brief Overview of BGP • Backbone protocol of the Internet • Used by providers to Advertise Routes, Attempt to Get Best Paths • Routes Exchanged by Peers using Autonomous System Numbers • BGP Rules • Local Pref • AS Hops • MEDs • Lowest Router ID Holly Brackett Pease USENIX NETA‘99

8. Challenges of Worldwide Routing • Ensuring Routes are Accepted • Providing Predictable Routing Paths • Limitations of BGP Holly Brackett Pease USENIX NETA‘99

9. Ensuring Routes are Accepted • Transit Traffic Paranoia Transit: Traffic that is not destined to or from a given provider’s customers, yet crosses that provider’s backbone • Policy 1: Only Accept Routes Originating from Direct Peers • Policy 2: Transit Agreements • Policy 3: Restrict Number of AS Hops on routes received from Peers • Policies usually Managed at Internet Exchanges Holly Brackett Pease USENIX NETA‘99

10. Ensuring Routes are Accepted • Transit Traffic Paranoia (cont’d) • Some downstream providers choose “none of the above” • Want to maintain market share in countries - no direct peering with in-country peers • Don’t want to pay for Transit Agreements • If No Direct Peers, Policy #3 is useless • 3 Solutions: • Ask nicely • Pay to Peer • Suffer the Consequences Holly Brackett Pease USENIX NETA‘99

11. Ensuring Routes are Accepted • A Government-regulated Internet Exchange • Israel’s IIX • operated by Israeli Internet Society (ISOC-IL) • non-profit • regulated by Ministry of Communications • Strict Local Policies • Only accepts Israeli-registered routes Holly Brackett Pease USENIX NETA‘99

12. Providing Predictable Routing Paths • Control Your Advertisements • Send Metrics • Use Specifics • No-Export • US Tier-1 Providers: Private Peering • Inconsistent • Congested Pipes Holly Brackett Pease USENIX NETA‘99

13. Providing Predictable Routing Paths • C&W (previously mci.net) Routing Policy • Local Pref All Routes Received from Customer Peers • Problem: Some US-based Downstream providers hear Digital Island through International Points • equal AS Hops • Solution: Force Peers who are C&W customers not to Advertise to C&W • UUNET • No local-pref default, but similar policy for controlling routing within net Holly Brackett Pease USENIX NETA‘99

14. Providing Predictable Routing Paths • BGP Limitations • BGP Routing Extremely Limited • Metrics, Local Pref, AS Hops, Specific Advertisements extremely limited tools • Does not account for link speeds, congestion Holly Brackett Pease USENIX NETA‘99

15. Every Day Application • Multi-homed Environment • Understand your provider’s routing policies • Control your Advertisements • Learn the “true” best route and operate accordingly • International Internet Connectivity • Advertise Specifics • Use Geographic AS’s Holly Brackett Pease USENIX NETA‘99

16. Every Day Application • International Application Deployment • Understand your provider’s connectivity • Test your provider • Make your provider work for you Holly Brackett Pease USENIX NETA‘99

17. Logistics of Deploying a Global Environment • International Carriers • Americans are in such a hurry • What’s an NTU? • X.21 is not a movie rating • Be precise about the interface you expect; then pray • Customary Problems • Are you ready? • Value-Added Tax • Who shipped what, when? Holly Brackett Pease USENIX NETA‘99

18. Logistics of Deploying a Global Environment • There’s no Fry’s in Europe • You don’t accept VISA? • Anixter is your friend (this is not an endorsement) • Everything takes twice as long as you thought it would Holly Brackett Pease USENIX NETA‘99