A QoS Control Method Cooperating with a Dynamic Load Balancing Mechanism

1. A QoS Control Method Cooperating with a Dynamic Load Balancing Mechanism Akiko Okamura, Koji Nakamichi, Hitoshi Yamada and Akira Chugo Fujitsu Laboratories Ltd. 4-1-1, Kamikodanaka, Nakahara, Kawasaki, 211-8588, Japan Telephone: +81-44-754-2635 Fax: +81-44-754-2741 E-mail address: {akikoo, nakamichi, hitoshi, chugo}@flab.fujitsu.co.jp Fujitsu Laboratories Ltd.

2. Introduction • Current IP network problems • End user's viewpoint • Degraded of performance (e.g., lowered throughput and increased delay) due to congestion • Network operator's viewpoint • Profits do not improve though traffic increases every year • Frequent bandwidth increases needed to support traffic increases • Services supporting usage-based billing are limited • To overcome these problems • Provide QoS guaranteed service • Develop fee/charge system based on network QoS • Use network resources efficiently --> IP traffic control mechanism is required Fujitsu Laboratories Ltd.

3. +Dynamic flow splitting +Multi route & path control +Explicit routing Minimum hop routing Our Approach to IP Traffic Control High Traffic Engineering (TE) Proposed method Future Dynamic load balancing Static load balancing Level of network efficiency Explicit path setup Connectionless approach(Diffserv) Connection-orientedapproach(IntServ) Hop-by-hop forwarding Low Best Effort ＋ Packet- priority mechanism ＋ Admission policing shaping ﾞ ＋ Performance monitoring reporting ＋Account-refund QoS: quality of service SLA: service level agreement SPF: shortest path first Low High Level of QoS/SLA Fujitsu Laboratories Ltd.

4. Traffic Engineering (TE) • Description • Improves traffic performance • Facilitates reliable network operations • A main application of multiprotocol label switching (MPLS) Constraint-based routing (explicit routing) • Example Applications • Static/dynamic load balancing • Achieves highly reliabile network by avoiding congestion/failure • Enables efficient use of bandwidth resources --> Functions of dynamic load balancing have been proposed • Fast Reroute Achieves highly reliabile network through high-speed failure recovery Fujitsu Laboratories Ltd.

5. Basic Architecture of Proposed Method- Cooperation between dynamic load balancing and providing QoS guarantee - TE Controller • Statistics monitoring (Network, Application servers) • Admission control • Load balancing control for best effort traffic QoS request Application Server • QoS path control for guaranteed class traffic User • Best Effort path • Original path = minimum hop route • Detour route used when there is congestion • QoS path • Bandwidth reserved • High priority at scheduling • Optimum route considering both network and application server resources MPLS Network MPLS: multi-protocol label switching Fujitsu Laboratories Ltd.

6. QoS Routing Algorithm total cost = server cost + link cost server cost: 1/(residual available output rate) link cost: 1/(residual available bandwidth) • Minimize total cost of link and server server cost is high… B C TOTAL COST is MINIMUM! A D E User Link D-E cost is high… link cost server cost Fujitsu Laboratories Ltd.

7. Server location candidate OC3 (155 Mbps) T3 (45 Mbps) Evaluation of QoS Routing:Metrics and Model • Metrics • Number of QoS requests accepted • Average number of hops in QoS paths Compared with • LSL method (lowest server load) • DNS method (domain name server) • Simulation model • ISP network, 19 nodes • Application servers • Four • Capacity of 500 Mbps • QoS requests • 1-10 Mbps bandwidth guarantee (random) • User’s edge selected at random (user’s edge ≠ server’s edge) 1st step Select server with lowest load 2nd step Select minimum cost route to server Select nearest server Fujitsu Laboratories Ltd.

8. 400 3.2 300 3.0 2.8 2.6 200 2.4 2.2 100 2.0 1.8 0 200 400 600 800 0 0 200 400 600 800 Evaluation of QoS Routing: Results • Effect of QoS routing considering both server and network loads • Accommodates many more requests • Provides QoS path with the smallest number of hops LSL method DNS method Number of requests accepted Average number of hops Our Proposal Number of QoS requests Number of QoS requests Fujitsu Laboratories Ltd.

9. 100 Mbps BE: 50 Mbps GS Evaluation of Dynamic Load Balancing:Metric, Model, and Conditions • Evaluate effect of dynamic load balancing under GS traffic conditions • Metric Throughput of BE traffic • Model 5-node-ring model with 100 Mbps links • Conditions • 50 Mbps BE traffic • Bandwidth reserved for GS traffic is increases to 80 Mbps. • Actual amount of GS traffic fluctuates • Congestion detection conditions • Actual (GS+BE) traffic > 80 Mbps • (Reserved GS + Actual BE) traffic > 80 Mbps Reserved Actual GS traffic Fujitsu Laboratories Ltd.

10. Evaluation of Dynamic Load Balancing: Results Throughput remains almost maximum. BE traffic with D-LB D-LB1 (condition A, solid line) D-LB2 (condition B, × signs) • Input BE Traffic • = 50 Mbps (fixed) Throughput [Mbps] • D-LB:Dynamic load balancing Bandwidth reserved for GS traffic BE traffic without D-LB Throughput decreases because load cannot be moved to other available links. Actual GS traffic Time [s] Fujitsu Laboratories Ltd.

11. Implementation - Snapshot of Operation Screen - Control status display panel (Path setting, load balancing, etc.) Path-setting status display Detailed path information Click Fujitsu Laboratories Ltd.

12. Conclusion & Future Work Conclusion Proposed method effectively utilizes resource while providing QoS • QoS routing based on network and server loads • Number of QoS requests accepted is improved • Server and network load balancing are achieved • Use of dynamic load balancing effectively provides QoS-guaranteed service • Degradation in BE traffic throughput when GS traffic is fluctuating is avoided Future work • Evaluation of performance in large-scale network • Development of more advanced QoS control method based on TE Fujitsu Laboratories Ltd.