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

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

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

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

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

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

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

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

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

UNIVERSITY OF JYVÄSKYLÄ 2005 Simulation topology

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

UNIVERSITY OF JYVÄSKYLÄ 2005 Results  Low utilization – Throughput

UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Delay

UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Loss

UNIVERSITY OF JYVÄSKYLÄ 2005 Results  High utilization – Throughput

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

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

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

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

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

UNIVERSITY OF JYVÄSKYLÄ 2005 ADC network topology

UNIVERSITY OF JYVÄSKYLÄ 2005 The end