apnoms2003fujitsu laboratories ltd.1 a qos control method cooperating with a dynamic load balancing...
TRANSCRIPT
Fujitsu Laboratories Ltd. 1APNOMS2003
A QoS Control Method Cooperating with a Dynamic Lo
ad 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. 2APNOMS2003
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. 3APNOMS2003
Our Approach to IP Traffic Control
QoS: quality of serviceSLA: service level agreementSPF: shortest path first
Level of
netw
ork
effi
cien
cy
TrafficEngineering (TE)
Minimum hop routing
+Explicit routing
+Multi route
& path
control
+Dynamic flow
splitting
BestEffort
+Packet- priority
mechanism
+Admissionpolicing
shaping ゙
+Performance monitoringreporting
+Account-refund
Connectionless approach(Diffserv)
Connection-orientedapproach(IntServ)
Explicit path setup
Static load balancing
Dynamic load balancing
Low High
Low
High
Level of QoS/SLA
Future
Hop-by-hopforwarding
Proposed method
Fujitsu Laboratories Ltd. 4APNOMS2003
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 RerouteAchieves highly reliabile network through high-speed failure recovery
Fujitsu Laboratories Ltd. 5APNOMS2003
Basic Architecture of Proposed Method- Cooperation between dynamic load balancing and providing QoS guarantee -
TE Controller
QoS path control for guaranteed class traffic
QoS path Bandwidth reserved High priority at scheduling Optimum route considering both network and application server resources MPLS: multi-protocol label switching
MPLS Network
Best Effort path Original path = minimum hop route Detour route used when there is congestion
Application Server
Statistics monitoring (Network, Application servers)
User
QoS request
Load balancing control for best effort traffic
Admission control
Fujitsu Laboratories Ltd. 6APNOMS2003
QoS Routing Algorithm• Minimize total cost of link and server
total cost = server cost + link cost
server cost: 1/(residual available output rate)link cost: 1/(residual available bandwidth)
link costserver cost
User
TOTAL COST is
MINIMUM!
Link D-E cost is high…
A
B
CD
E
server cost is high…
Fujitsu Laboratories Ltd. 7APNOMS2003
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)
OC3 (155 Mbps)
T3 (45 Mbps)
Server locationcandidate
Select server with lowest load Select minimum cost
route to serverSelect nearest server
1st step
2nd step
Fujitsu Laboratories Ltd. 8APNOMS2003
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
0
100
200
300
400
Number of QoS requests
Nu
mb
er
of
req
uests
accep
ted
0 200
400 600 8000 200 400 600 800 Number of QoS requests
2.83.03.2
2.0
2.6
2.4
2.2
1.8
Avera
ge n
um
ber
of
hop
s
DNS method
Our Proposal
LSL method
Fujitsu Laboratories Ltd. 9APNOMS2003
Evaluation of Dynamic Load Balancing:Metric, Model, and Conditions
• Evaluate effect of dynamic load balancing under GS traffic conditions
• MetricThroughput of BE traffic
• Model5-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
A) Actual (GS+BE) traffic > 80 Mbps B) (Reserved GS + Actual BE) traffic > 80 Mbps
100 Mbps
BE: 50 Mbps
GS
Reserved
Actual GS traffic
Fujitsu Laboratories Ltd. 10APNOMS2003
Evaluation of Dynamic Load Balancing: Results
Time [s]
Th
rou
gh
pu
t [M
bp
s]
Actual GS trafficActual GS traffic
BE traffic with D-LBD-LB1 (condition A, solid line)D-LB2 (condition B, × signs)
BE traffic with D-LBD-LB1 (condition A, solid line)D-LB2 (condition B, × signs)
BE traffic without D-LBBE traffic without D-LB
Bandwidth reservedfor GS traffic
Throughput decreases because load cannot be moved to other available links.
Throughput decreases because load cannot be moved to other available links.
•Input BE Traffic = 50 Mbps (fixed)
Throughput remains almost maximum.
Throughput remains almost maximum.
•D-LB:Dynamic load balancing
Fujitsu Laboratories Ltd. 11APNOMS2003
Implementation
Path-setting status display
- Snapshot of Operation Screen -
Click
Control statusdisplay panel(Path setting, load balancing, etc.)
Detailed path information
Fujitsu Laboratories Ltd. 12APNOMS2003
Conclusion & Future Work
ConclusionProposed 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