1 NGcN 2003 차세대통합네트워크 테스트베드 및 서비스 - A Case of Mobile Internet - Myungchul Kim

2 NGcN 2003 Contents All IP networks with QoS guarantee and Mobility support VoIP over Mobile IP –Soonuk Seol, Myungchul Kim, and et al., "Experiments and Analysis of Voice over Mobile IP", the 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2002), Lisbon, Portugal, September 2002 MPEG streaming over Mobile Internet –Kyounghee Lee, Myungchul Kim, and et al., "CORP - A Method of Concatenation and Optimization for Resource Reservation Path in Mobile Internet", IIEICE Transaction on Communications Special Issue on Internet Technology III, Vol. E86-B, No2, Feb –Myungjin Lee, Kyounghee Lee, Myungchul Kim, and et al., "MPEG Streaming over Mobile Internet", IS&T/SPIE’s 14th Annual Symposium, Electronic Imaging 2002.

3 NGcN 2003 Voice over Mobile IP

4 NGcN 2003 Motivation Voice over IP –Internet telephony is one of the most promising services –low cost, efficient bandwidth utilization, integration with data traffic –Support only best effort service, more obstacles to deteriorate voice quality, e.g., delay, delay jitter, packet loss, etc. –There are two competing approaches for VoIP ITU’s H.323 [1,2], IETF’s SIP [3] Mobility demand –VoIP needs to support most functionalities that the current PSTN does, especially mobility support. All-IP trends –Recently, it is believed all mobility-related functionality should be handled at the IP (network) layer [10,11,12,13].

5 NGcN 2003 Related Work Extensions to H.323 for mobility [8,9] : –Additional messages and functionalities to H.323 system –Require application to perform mobility management Mobility support to SIP –Moh et al. [5] Address several major issues for supporting mobility on SIP –Wedlund and Schulzrinne [6] An application level approach for real-time mobile communication. Does not support mobility to the applications that are independent of SIP Impossible to use SIP mobility in which network do not support DHCP Overhead with mobile IP –A waste of resources to keep duplicated information about the hosts current address. (both in SIP servers and Home agents)

6 NGcN 2003 Related Work (cont.) In our experiments –Need a homogeneous mobility solution support regardless of wireless interfaces and applications. –Depend on Mobile IP [4] for mobility management

7 NGcN 2003 What we have achieved Examine the feasibility of SIP over Mobile IP for Internet telephony –Investigate various factors that affect delay, packet loss, and load on the network –Experiment with encapsulation and decapsulation delay time and interarrival time in many aspects, comparing with normal IP. Find the desirable number of frames per packet in Mobile IP as a function of packet transmission delay and bandwidth utilization.

8 NGcN 2003 Backgrounds Mobile IP –Allows a mobile node to communicate with other nodes transparently in spite of address change due to its mobility –Triangular routing problem which increases delays –Route optimization solve delay increase problem by using binding updates.

9 NGcN 2003 Backgrounds Session Initiation Protocol (SIP) –SIP allows two or more participants to establish a session consisting of multiple media streams. –In SIP, callers and callees are identified by SIP address. –When making a SIP call, a caller first locates the appropriate server and then sends a SIP request. –SIP server can act in two different modes Proxy server –requests to the next hop or user-agent within an IP cloud Redirect server –informs their clients of the address of the requested server –allow for the client to contact that server directly

10 NGcN 2003 Testbed Configuration Mobile IP: Dynamics, SIP: Linphone, GSM codec is used Analysis with TCPDUMP(for capturing packets) and Ping IEEE PC Card 11 Mbit/s

11 NGcN 2003 RTP packet format Length of a packet : 87 bytes –IP header : 20 bytes, IP option : 14 bytes –UDP header : 8 bytes –RTP message : 45 bytes ( RTP header : 8bytes, Voice data: 33 bytes)

12 NGcN 2003 Encapsulation delay Encapsulation and decapsulation delay : ~ 1ms –Measure the encapsulation and decapsulation delay by configuring the routing path between MH and CH in mobile IP to be identical to that of not using mobile IP. FA1 HA CH FA1 HA CH

13 NGcN 2003 Interarrival time w/o Mobile IP –Sending rate : 20 ms –Interarrival time : ~ ms with 99% confidence –Standard deviation : 0.5 ms –Number of samples : 700

14 NGcN 2003 Interarrival time with Mobile IP –Sending rate : 20 ms –Interarrival time : ~ ms with 99% confidence –Standard deviation : 0.89 ms –Number of samples : 700

15 NGcN 2003 Interarrival time in voice conversation(1) Bi-directional voice conversation for 60 sec. Average: 20ms, overall within 42ms for three cases: (a) IP (b) Mobile IP without handoffs (c) Mobile IP with 5 times of handoffs

16 NGcN 2003 Interarrival time in voice conversation(2) Overall packets arrive within 42 ms. (make up with buffers) No many differences during the handoff time. Mobile node –can receive packets from the old foreign agent. –gets a care-of address from the FA not from the DHCP server. FA1 HA CH FA2 h->F1 c->m h->F2 c->m MH FA1 HA CH FA2 MH

17 NGcN 2003 Interarrival time under background traffic –five extra sessions for MN with different hosts, totally 6300 packets (~2min) for each call –The longest : Normal IP = 25 ms, Mobile IP = 30 ms –98% of packets = 18 ~ 22 ms –Traditional packet loss

18 NGcN 2003 Total Data Size for Different frames/pkt One-way voice data –Totally, 297 Kbytes for 180 sec (one frame : 33 bytes) –IP & UDP headers: add 54 bytes –Encapsulation (from HA to FA): adds 20 bytes

19 NGcN 2003 The Desirable Number of Frames Mobile IP Network –need to save the bandwidth (esp., wireless network) End to end delays –Smaller than 150 ms : not perceived –Between 150 and 400 ms : acceptable but not ideal –If f/p=3: about 60ms’ latency to aggregate three frames. The rest 90ms (150-60) are remained for packet transfer.

20 NGcN 2003 Conclusion and Future work Feasibility of Mobile IP-based SIP –Mobile IP’s encapsulation and decapsulation delay is short enough for interactive audio applications. –Interarrival time does not vary much. Desirable number of frames per packet –Sends three frames per packet to reduce loads on the campus- sized network Future work –Simulate SIP over Mobile IP for large scaled networks –study various kinds of codecs in the same context and in terms of the number of hops. –delay-aware and/or load-aware scheme for Internet Telephony

21 NGcN 2003 References [1] Gary A. Thom, “H.323: the Multimedia Communications Standard for Local Area Networks,” IEEE Communications Magazine, December [2] ITU-T Rec. H.323v2, “Packet Based Multimedia Communications Systems,” March [3] M. Handley et al., “SIP: Session Initiation Protocol,” IETF RFC 2543, March [4] C. Perkins, “IP Mobility Support,” RFC 2002, IETF, October [5] Melody Moh, Gregorie Berquin, and Yanjun Chen, “Mobile IP Telephony: Mobility Support of SIP,” Eighth International Conference on Computer Communications and Networks, [6] Elin Wedlund and Henning Schulzrinne, “Mobility Support using SIP,” Proceedings of the second ACM International Workshop on Wireless Mobile Multimedia (WoWMoM), [7] X. Zhao, C. Castelluccia, and M. Baker, “Flexible Network Support for Mobility,” in Proceedings of Mobicom, October [8] ITU-T Draft Recommendation H.MMS.1, “Mobility for H.323 Multimedia Systems,” March [9] Wanjiun Liao, “Mobile Internet Telephony: Mobile Extensions to H.323,” INFOCOM ’99. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings. IEEE, June [10] Ramachandran Ramjee, Thomas F. La Porta, Luca Salagrelli, Sandra Thuel, and Kannan Varadhan, “IP-based Access Network Infrastructure for Next-Generation Wireless Data Networks,” IEEE Personal Communications, August [11] Shingo Ohmori, Yasushi Yamao, and Nobuo Nakajima, “The Future Generations of Mobile Communications Based on Broadband Access Technologies,” IEEE Communications Magazine, December 2000.

22 NGcN 2003 References (cont.) [12] Ramón Cáceres and Venkata N. Padmanabhan, “Fast and Scalable Wireless Handoffs in Supports of Mobile Internet Audio,” Mobile Networks and Applications 3, December [13] Mihailovic, A., Shabeer, M., and Aghvami, A.H., “Multicast for Mobility Protocol (MMP) for Emerging Internet Networks,” The 11th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), [14] H. Schulzrinne and J. Rosenberg, “A Comparison of SIP and H.323 for Internet Telephony,” [15] James F. Kurose and Keith W. Ross, “Computer Networking – A Top-Down Approach Featuring the Internet”, Addison Wesley Longman, [16] Charles Perkins and David B. Johnson, “Route Optimization in Mobile IP,” draft-ietf- mobileip-optim-11.txt (Work in progress), September [17] David B. Johnson and Charles Perkins, “Mobility Support in IPv6,” draft-ietf-mobileip-ipv6- 13.txt (Work in progress), July [18] Dynamics – HUT Mobile IP, available at [19] Linphone – a SIP application, available at

23 NGcN 2003 MPEG Streaming over Mobile Internet

24 NGcN 2003 Introduction General multimedia data characteristics –Intolerant to delay and jitter variance –Error-sensitive Characteristics of mobile Internet –Frequent routing path changes due to handoffs –Higher error rate in wireless link Effects on streaming multimedia data in mobile Internet –Handoff delay –Re-routing toward congested network  delay increment –Higher packet loss probability due to mobility  Significant quality degradation of streaming multimedia data

25 NGcN 2003 Introduction (cont’d) Popular Quality of Service (QoS) guarantee mechanisms –Differentiated Service (DiffServ) [2] Guarantees aggregated QoS for multiple flows Can not guarantee specific QoS requirement for each data flow –Integrated Service (IntServ) Network resource reservation for specific data flow Strict guarantees for multimedia streams with various QoS requirements Resource Reservation Protocol (RSVP) [3]

26 NGcN 2003 Introduction (cont’d) Problems of RSVP in Mobile Internet –Mobile Host (MH) handoff invalidates existing reservation paths  overhead and delay to re-establish new RSVP session –Movement to congested wireless cell  fail to get admission to re-establish new RSVP session  Seamless QoS guarantees are impossible Existing approaches –Mobile RSVP (MRSVP) [15] –Hierarchical Mobile RSVP (HMRSVP) [16] –A method of Concatenation and Optimization of Reservation Path (CORP) [10]

27 NGcN 2003 Related Work CORP –Base Station (BS) takes charge of making and managing RSVP sessions on behalf of MH –Consists of two main processes Concatenation of Reservation Path (CRP) process –Reservation path extension technique –Current BS pre-establishes pseudo reservation path (PRP) toward its neighboring BSs to prepare for MH’s handoff –When MH handoffs, corresponding PRP is activated to guarantee QoS for MH Optimization for Reservation Path (ORP) process –Solves infinitely long path extension problem and reservation path loop problem of CRP process –Optimizes the extended reservation path

28 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors CRP inform CORP message RSVP session PRP Activated PRP

29 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors III.BS_B makes PRP to its neighbors CORP message RSVP session PRP Activated PRP

30 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors III.BS_B makes PRP to its neighbors IV.MH handoffs toward BS_C’s cell CORP message RSVP session PRP Activated PRP

31 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors III.BS_B makes PRP to its neighbors IV.MH handoffs toward BS_C’s cell CRP activate V.BS_C sends CRP activate message to the previous BS (BS_B) CORP message RSVP session PRP Activated PRP

32 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors III.BS_B makes PRP to its neighbors IV.MH handoffs toward BS_C’s cell V.BS_C sends CRP activate message to the previous BS (BS_B) VI.BS_B forwards MPEG-1 video through the activated PRP CORP message RSVP session PRP Activated PRP

33 NGcN 2003 Related Work (cont’d) CRP Process BS_CBS_BBS_A I.MH requests a new RSVP session and BS_B makes it on behalf of the MH II.BS_B sends CRP inform messages to its neighbors III.BS_B makes PRP to its neighbors IV.MH handoffs toward BS_C’s cell V.BS_C sends CRP activate message to the previous BS (BS_B) VI.BS_B forwards MPEG-1 video through the activated PRP VII.BS_B terminates useless PRP toward BS_A CORP message RSVP session PRP Activated PRP

34 NGcN 2003 Related Work (cont’d) ORP Process BS_CBS_BBS_A CORP message RSVP session PRP Activated PRP I.BS_C sends IGMP group report message to its gateway router IGMP report

35 NGcN 2003 Related Work (cont’d) ORP Process BS_CBS_BBS_A CORP message RSVP session PRP Activated PRP I.BS_C sends IGMP group report message to its gateway router II.BS_C joins into the existing multicast RSVP session CRP release III.BS_C sends CRP release message to the previous BS (BS_B)

36 NGcN 2003 Related Work (cont’d) ORP Process BS_CBS_BBS_A CORP message RSVP session PRP Activated PRP I.BS_C sends IGMP group report message to its gateway router II.BS_C joins into the existing multicast RSVP session III.BS_C sends CRP release message to the previous BS (BS_B) IV.BS_B terminates the activated PRP and BS_C uses the newly optimized one to deliver MPEG data stream to MH

37 NGcN 2003 Related Work (cont’d) ORP Process BS_CBS_BBS_A CORP message RSVP session PRP Activated PRP I.BS_C sends IGMP group report message to its gateway router II.BS_C joins into the existing multicast RSVP session III.BS_C sends CRP release message to the previous BS (BS_B) IV.BS_B terminates the activated PRP and BS_C uses the newly optimized one to deliver MPEG data stream to MH V.BS_B leaves the multicast RSVP session CRP inform CRP inform VI.BS_C sends CRP inform messages to its neighbors to prepare MH’s probable movement

38 NGcN 2003 Proposed Mechanism Motivation –To provide QoS guarantees for MPEG video streaming services with mobility support Proposed System –Uses CORP to guarantee seamless QoS in mobile networks –Provides MPEG-1 video streaming services over CORP –CORP-aware video streaming server and client –CORP-capable mobile agents (Base Stations)

39 NGcN 2003 System Design Video Server Architecture –CORP adaptation module handles CORP messages and takes charge of resource reservation process –MPEG-1 traffic transfer module transfers MPEG-1 stream to BS at the speed of a reserved bandwidth CORP message MPEG-1 data

40 NGcN 2003 System Design (cont’d) Base Station Architecture –CORP message handler module handles CORP messages which are generated by neighboring BSs or a mobile client –traffic forward module receives MPEG-1 streaming data from the video server and forwards it to a neighboring BS or directly delivers it to the client

41 NGcN 2003 System Design (cont’d) Client Architecture –CORP adaptation module handles CORP messages –Handoff detection module detects a handoff and determines when MH has to request the activation of PRP –MPEG-1 traffic receiver module receives MPEG-1 streaming data from a current BS –MPEG-1 video playback module plays the MPEG-1 video from the received stream

42 NGcN 2003 System Design (cont’d) MPEG-1 Service Procedure over CORP before Handoff Video ServerBS1ClientBS2 Service Request Service Request Ack Service Request Service Request Ack RSVP path RSVP resv MPEG-1 traffic PRP establishment Client Handoffs (BS1  BS2)

43 NGcN 2003 System Design (cont’d) MPEG-1 Service Procedure over CORP after Handoff Video ServerBS1ClientBS2 Client handoffs CRP Activate Request CRP Activate CRP Activate Ack MPEG-1 traffic ORP Request ORP Request Ack RSVP path RSVP resv MPEG-1 traffic (BS1  BS2)

44 NGcN 2003 Testbed Configuration Network Architecture Wired subnet bandwidth 10 Mbps Ethernet Wireless subnet bandwidth IEEE b wireless LAN with the bandwidth of 11 Mbps BS Runs FA daemon of Mobile IP Runs CORP daemon Client Runs MH daemon of Mobile IP Runs VOD client program Video Server Supports CORP-aware MPEG-1 streaming service MH BS2 Gateway BS1 Video Server Wireless Subnet_1Wireless Subnet_2 Wired Subnet_1Wired Subnet_2 Home Agent

45 NGcN 2003 Experiments Experiment Scenarios –Background traffic generation: MGEN –Maximum throughput of wired network: 9.34 Mbps –Wired subnet_1: non-congested –Wired subnet_2: congested 8.2 Mbps background traffic –Movement of MH: BS1  BS2 Experiment Cases I.MPEG-1 streaming with CORP and TCP II.MPEG-1 streaming with TCP only III.MPEG-1 streaming with CORP and UDP IV.MPEG-1 streaming with UDP only Shrek Resolution352 X 288 Average Data Rate (Mbps) 1.39 Frame Rate (fps)25 Play out duration (sec) 80 Total number of frames 2,000 Sample Video Clip Specification

46 NGcN 2003 Performance Evaluation QoS Guarantee –Data rate is measured at client per each second while the sample MPEG file is being delivered –Not much difference in data rate distribution between before and after handoff cases in (I) –Amount of packet loss due to handoff is about 81Kbytes in (I) –84 percents are less than 0.3 Mbps after handoff in(II) I. MPEG-1 Streaming with CORP and TCPII. MPEG-1 Streaming with TCP only * 150KBps bandwidth reserved

47 NGcN 2003 Performance Evaluation (cont’d) QoS Guarantee (cont’d) –Not much difference in data rate distribution between before and after handoff cases in (I) –Average data rate before handoff is significantly higher than that after handoff in (II) –Average packet loss rate is about 0.6 Mbps in (II) I. MPEG-1 Streaming with CORP and UDPII. MPEG-1 Streaming with UDP only * 200KBps bandwidth reserved

48 NGcN 2003 Performance Evaluation (cont’d) Quality of Streaming Video –If Peak Signal to Noise Ratio (PSNR) is less than 20 dB, the frame can be regarded as being lost –In (I), MPEG-1 streaming data did not suffer from loss or delay under the congested situation –11 frames were lost during CRP process time in (I) –the total number of received frames is only 1107 frames out of 2000 frames for 80 seconds in (II) I. MPEG-1 Streaming with CORP and TCPII. MPEG-1 Streaming with TCP only

49 NGcN 2003 Performance Evaluation (cont’d) Quality of Streaming Video (cont’d) –The average PSNR is 69.6 dB before MH’s handoff and 68.6 dB after MH’s handoff in (I) –MH could not play back MPEG-1 video stream correctly after handoff in (II) because of too high packet loss rate (0.6 Mbps) I. MPEG-1 Streaming with CORP and UDPII. MPEG-1 Streaming with UDP only

50 NGcN 2003 Conclusions QoS guarantee for MPEG-1 streaming service in Mobile Internet –QoS guarantee mechanism with mobility support – CORP –Implementation of MPEG-1 streaming service over CORP Streaming Video Quality Improvement –Significantly better PSNR values in both cases of using TCP and UDP when CORP mechanism is applied –MPEG-1 streaming with CORP and TCP provided the highest video quality in the experiments Future work –Reduction in the packet loss during a handoff with CORP –Reduction in the packet loss over wireless links when UDP is used as a transport protocol

51 NGcN 2003 References [1] B. Adamson, “The MGEN Toolset,” USA, [2] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, and W. Weiss, “An Architecture for Differentiated Services,” RFC 2475, IETF, [3] R. Branden, L. Zhang, S. Berson, S. Herzog, and S. Jamin, “Resource ReSerVation Protocol (RSVP) – Version 1 Functional Specification,” RFC 2205, IETF, [4] F. Cheong and R. Lai, “A study of the burstiness of combined MPEG video and audio bitstreams,” Computer Communications, 21(10), pp , [5] L. deCarmo, “Core Java media framework,” Prentice-Hall, [6] W. Fenner, “Internet Group Management Protocol, Version 2,” RFC 2236, IETF, [7] D. L. Gall, “MPEG: a video compression standard for multimedia applications,” Communications of ACM, 34(4), pp , [8] R. Gordon, “Essential JNI: Java Native Interface,” Prentice-Hall, [9] R. Gordon and S. Talley, “Essential JMF: Java Media Framework,” Prentice-Hall, [10] K. Lee, “A Method of Concatenation and Optimization for Resource Reservation Path (CORP) in Mobile Internet,” M.S. Thesis, ICU, [11] J. K. Ng, “A reserved bandwidth video smoothing algorithm for MPEG transmission,” Journal of Systems and Software, 48, pp , [12] C. Perkins, “IP Mobility Support,” RFC 2002, IETF, 1996.

52 NGcN 2003 References (cont.) [13] R. R. Pillai and M. K. Patnam, “A method to improve the robustness of MPEG video applications over wireless networks,” Computer Communications, 24, pp , [14] S. C. Sullivan, L. Winzeler, J. Deagen, and D. Brown, “Programming with the Java Media Framework,” John Wiley & Sons, Inc., [15] A. K. Talukdar, B. R. Badrinath, and A. Acharya, “MRSVP: A Reservation Protocol for an Integrated Service Packet Network with Mobile Hosts,” Technical Report: DCS-TR- 337, Rutgers university, USA. [16] C. Tseng, G. Lee, and R. Liu, “HMRSVP: a hierarchical mobile RSVP protocol,” Distributed Computing Systems Workshop, 2001 Int’l Conf. on, pp , [17] “Dynamics – HUT Mobile IP,” Finland, [18] “Java Media Framework API Guide,” media/jmf/index.html, Sun Microsystems, USA, [19] “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher speed Physical Layer Extension in the 2.4 GHz Band,” IEEE Standard b, IEEE, USA, 1999.