Spring-based Resource Management for End-to-end Services in Next- generation Networks JOURNAL OF INFORMATION SCIENCE AND ENGINEERING YANG-HUI CHANG, TEIN-YAW CHUNG AND YUNG- MU CHEN Reporter: Chia-Nung Wang

2 Outline Spring system and definition Spring-based resource allocation algorithm (SBRA) Spring-based resource compensation algorithm (SRCA) Reactive force suppression (RFS) Simulation Conclusion

3 Spring system and definition For a spring system, there are there attributes. Regular length (L R ) Minimum length (L min ) Spring factor (x) f As before, a force f can decides the length of the spring by this formula:

4 Spring system and definition 2 Defines the resource profile of entity i for a specific resource as: R i (L Ri,L mini,L maxi,x i )

5 Spring-based resource allocation algorithm (SBRA) SBRA considers only two important resources: Computing power Bandwidth There are a simple linear relationship between this two resource. The number of instructions required to process a packet. The average packet size processed by c i Correlation index

6 SBRA 2 The requirements of computing and bandwidth. Reallocates the computing quota according to bandwidth quota. Reallocates the bandwidth quota according to computing quota. allocates a single resource type first, and checks whether the corresponding allocation of the other resource is acceptable.

7 SBRA 3 The computing delay: The transmission delay: The total delay is: The delay bound is: The extra delay is: Total computing resources allocated to the entities.

8 Spring-based resource compensation algorithm (SRCA) A service S in this study is defined by a set of serially connected entities. When there are a extra delay, the service manager invoke SRCA to transfer to other iNode. Whose entities are involved in the same service to compensate for.

9 SRCA 2 Will suffer an extra delay To compensate the extra delay

10 SRCA 3 During resource re-allocation, iNodes allocate an extra resource to an entity to compensate for. The extra resource may affect the QoS of some other services and enable many new extra delay transferences by: Chain Reaction Relation (CRR). Starvation cycle.

11 SRCA 4 Chain Reaction Relation (CRR) If P 1 ∩ P 2 ∩ P 3 …∩ P n ≠ Ø, there exists a potential chain reaction set: When CRR occur, it will create many control messages because of delay compensation. When an iNode re-allocates its resources, it may cause all chain reactions in π and generate many Delay Transference Messages (DT_Message).

12 SRCA 5 Starvation cycle: There must be a service path cycle in a network. If the cycle exists a resource re-allocation and triggers chain reactions that may cause a starvation cycle. A starvation cycle not only is responsible for a lengthy call set up time but also triggers an infinite number of DT_Message.

13 Reactive force suppression (RFS) The study applies a novel approach called RFS to reduce the number of delay transferences during a call setup. RFS employs two mechanisms to suppress the delay transferences: Delay budget ε Reactive force F R

14 RFS 2 Delay budget : If then the iNode re-allocates resources to cover θ ex, but this re-allocation yields no any new DT_Message. If, iNode also re-allocates resources to cover θ ex and makes no any new DT_Message. However, entity x is removed from ξ because it has used up its entire quota. Finally, if,then the iNode cannot completely cover θ ex. Delay boundAverage delay Idle capability > new resource requirement for x to covering – existing resource

15 RFS 3 Reactive force F R Force F R is used mainly to avoid starvation cycles and reduce the number of DT_Messages generated by CRR. F R exploits two attributes rf and RF. rf denotes the number of extra delay transferences during the setup of a call. RF denotes the maximum value of rf. The maximum rf equals ξ n in the worst case.

16 Simulation 0.96 and 0.98 are better The improve in RF=n-2 is very close to these at RF=n

17 Simulation 2

18 Simulation 3 No ε With ε RF=n RF=n-2

19 Simulation 4

20 Conclusion In this paper, author provide an SRCA algorithm. In this algorithm, an extra delay suffered by an entity can be compensated by other entities belong to the same service. Uses a novel scheme, RFS, to avoid excessive control messages. RFS uses two mechanisms, Delay budget ε and Reactive force FR to limit extra delay transferences during the setup of a call.