1. UNIVERSITY OF JYVÄSKYLÄ 2005 Multicast Admission Control in DiffServ Networks Department of Mathematical Information Technology University of Jyväskylä Finland

2. UNIVERSITY OF JYVÄSKYLÄ 2005 Introduction  IPTV, video conferences, etc. are more and more transferred in the IP networks nowadays than earlier  Video services demand strict QoS limits in terms of delay, jitter and packet loss  Multicast is a relevant transmission mechanism for these services  Differentiated Services is likely to be the most used QoS architecture in future

3. UNIVERSITY OF JYVÄSKYLÄ 2005 The Methods  There are three different admission control methods; Measurement based 1&2 and Parameter based  The methods are distributed to the edge nodes  Based on filtering the join requests from customers  The admission control methods are divided into three distinct phases

4. UNIVERSITY OF JYVÄSKYLÄ 2005 Phase 1 – Edge test  Is common for all the methods  If the edge router that receives the join request already is forwarding the particular group, the join is automatically accepted  Otherwise, the method moves to the phase 2 before making any decisions

5. UNIVERSITY OF JYVÄSKYLÄ 2005 Phase 2 – Bandwidth test (1/2)  Measurement based methods 1 & 2:  Measurement 1 inspects if there is enough room on the links for the new receiver  Measurement 2, on the other hand, inspects if there is room within the class on every link  Based on MGRIP protocol  Checks only the path between egress edge node and branching node  Only the links whose utilization would increase are inspected

6. UNIVERSITY OF JYVÄSKYLÄ 2005 Phase 2 – Bandwidth test (2/2)  Parameter based method:  The available bandwidth is aproximated using the following equation:  Other assumptions are the same than with measurement based methods 1 & 2

7. UNIVERSITY OF JYVÄSKYLÄ 2005 Phase 3 – Measurement test (1/2)  Methods Measurement 1 and 2:  Egress edge joins the group, receives n first packets and calculates loss, delay and jitter for the packets  Exponential average of current and history results is used to compare against defined limits  Uses packets’ RTP headers to calculate QoS parameters

8. UNIVERSITY OF JYVÄSKYLÄ 2005 Phase 3 – Measurement test (2/2)  Parameter based method:  The maximum end-to-end delay, that can occur on the path, is approximated using the following equation:  In our simulation environment, every node tracks the number of active connections it is forwarding

9. UNIVERSITY OF JYVÄSKYLÄ 2005 Simulations  Simulations were done with ”Network Simulator 2”  Traffic of two customers was measured and other customers produced the background traffic  FTP, IPTV and video conference were used as the applications  Video traffic was produced from real captured video stream

10. UNIVERSITY OF JYVÄSKYLÄ 2005 Simulation topology

11. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Tens of identical simulations with different background traffic loads were ran  First case shows a situation in a slightly loaded network  Second case shows a situation with more loaded network  The last case presents the influence of backgroud traffic

12. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Low utilization – Throughput

13. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Delay

14. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Loss

15. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Throughput

16. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Background traffic’s effect on throughput

17. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Background traffic’s effect on delay

18. UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Background traffic’s effect on loss

19. UNIVERSITY OF JYVÄSKYLÄ 2005 Conclusions based on simulations  The need for admission control can be seen clearly  Our simple admission control method gives better quality for the customers being served  Decreased throughput and rejection of some of the requests is the cost of the method

20. UNIVERSITY OF JYVÄSKYLÄ 2005 ADC implementation  Linux workstation with more than 1 NIC as a Edge router  XORP is an open source IP router platform which is used to perform the router functionality  Unix IPtables is used to filter the packets needed for admission control decisions and measuring purposes  ADC implementation performs packet loss, jitter and delay calculations which it uses for decision making  Next, a multicast receiver implementations will be done to easily measure the quality of service experienced by the receivers

21. UNIVERSITY OF JYVÄSKYLÄ 2005 ADC network topology

22. UNIVERSITY OF JYVÄSKYLÄ 2005 The end