Holly Brackett Pease USENIX NETA‘99 Challenges Deploying a Global Network Holly Brackett Pease Director, Network Engineering Digital Island

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

Holly Brackett Pease USENIX NETA‘99 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 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 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 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 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 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 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 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 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 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