Xin Wang With Henning Schulzrinne Internet Real Time

Xin Wang With Henning Schulzrinne Internet Real -Time Laboratory Columbia University http: //www. cs. columbia. edu/~xinwang/RNAP. html

Today’s IP Networks Service Level Agreements (SLA) are negotiated based on Application Specific Needs bandwidth, loss, delay, jitter, availability, price A pp lic ISP Networks & Applications Application SLA IP at io n SL A Network Service User SCOPE n n Growth of new IP services and applications with different bandwidth and quality of service requirements Presents opportunities and challenges for service providers 10/20/2021 2

The needs of Next Generation Service Providers n n Revenue from the traditional connectivity services (raw bandwidth) is declining Increase revenue by offering innovative IP services: u u Deliever high-margin, differentiated services Vo. IP, VPN, Applications Hosting etc n Gain competitive advantage by deploying new services more quickly, placing a premium on time to market and time to scale n Reduce cost and operation complexity u u 10/20/2021 Evolve from static network management to dynamic service provisioning Reduce costs by automating network and service management 3

Internet Structure End User Regional Provider NAP LAN POP Regional Provider Backbone Provider Private Peering Backbone Provider 10/20/2021 Private Peering Private Network 4

NORDUnet Traffic Analysis 10/20/2021 5

NORDUnet Traffic Analysis n Results: u All access links (interconnect ISP’s or connect private networks to ISP’s), including trans-Atlantic links, can get congested. u Average utilization is low: 20 -30% u Peak utilization can be high: up to 100% è Congestion Ratio (peak/average): as high as 5. u Peak duration can be very long: è Chicago NAP congested once in 8/00, lasted 7 hours. è Tele. Globe links congested every workday in 8/00 and 9/00 n Reasons: Frequent re-configuration and upgrading; Load balancing to protect own users. 10/20/2021 6

Solution - Over-provisioning? n n Add enough bandwidth for all applications in access network / backbone Will over-provisioning be sufficient to avoid congestion? u How much bandwidth is enough to meet diverse user requirements? u No intrinsic upper limit on bandwidth use n How much does it cost to add capacity? 10/20/2021 7

Bandwidth Pricing n Reality: leased bandwidth price has not been dropping consistently and dramatically. n Facts: u 300 mile T 1 price (rent): è 1987: $10, 000/month è 1992: $4, 000/month è 1998: $6, 000/month (thanks to high Internet demand) u 100 -mile cabling cost in 1998: $65, 000 n Links connecting ISP’s are very expensive 10/20/2021 8

Bandwidth Pricing (cont. ) n Facts: u International Frame Relay with 256 -kbps: thousands dollars a month. u Transit DS-3 link: $50, 000/month between carriers. u Transit OC-3 link: $150, 000/month between carriers. u Chicago NAP: è$3, 900/month/DS-3, è$4, 700/month/OC-3. Bandwidth may be cheap, but not free Higher-speed connection -- higher recurring monthly costs. Option - manage the existing bandwidth better, with a service model which uses bandwidth efficiently. 10/20/2021 9

Solution - Other Service Models n Quality of Service (Qo. S) u Condition the network to provide predictability to an application even during high user demand u Provide multiple levels of Qo. S to meet diverse user requirements u How efficient a Qo. S mechanism manages the bandwidth? How much a user needs to pay for Qo. S? n Application adaptation u Source rate adaptation based on network conditions can avoid congestion and lead to efficient bandwidth utilization u Why would an application adapt? 10/20/2021 10

A more Efficient Service Model n Dynamic resource negotiation u Network commits resources for short intervals - better response to changes in network conditions and user demand n Usage-, Qo. S-, demand-sensitive pricing u Allow network to price services based on resources consumed, and allocate resources based on user willingness -to-pay u Give user incentive to select appropriate service based on requirements, adapt demand during network resource scarce in response to price increase 10/20/2021 11

What We Add to Enable This Model? n A dynamic resource negotiation protocol: RNAP u u u u n An abstract Resource Negotiation And Pricing protocol Enables user and network (or two network domains) to dynamically negotiate multiple services with different Qo. S characteristics Enables network to formulate and communicate prices and charges Lightweight and flexible: embedded in other protocols, e. g. , RSVP, or implemented independently Ensures service predictability: commit service and price for an interval Supports multi-party negotiation: senders, receivers, or both Reliable and scalable A demand-sensitive pricing model u u 10/20/2021 Enables differential charging for supporting multiple levels of services; services priced to reflect the cost and long-term user demand Allows for congestion pricing to motivate user adaptation 12

What we add. . . (cont’d) n n Demonstrate a complete resource negotiation framework (RNAP, pricing model, user adaptation) on test-bed network Simulations show significant advantages relative to static resource allocation and fixed pricing: u Much lower service blocking rate under resource contention u Service assurances under large or bursty offered loads, without high provision complexity, or over-provision cost u Higher perceived user benefit and higher network revenue 10/20/2021 13