Tham khảo tài liệu 'multimedia_chuong4_bkhn', kỹ thuật - công nghệ, kĩ thuật viễn thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Chapter 4 Multimedia Network Applications Overview Part 1 Multimedia requirements-Application classes Part 2 streaming applications Part 3 Voice over IP VoIP Part 4 Recovery from Packet Loss Part 5 RTP Real Time Protocol Part 6 Int-serv Diff-serv RSVP 4 2 2003 Nguyen Chan Hung-Hanoi University of Technology 1 Part 1. Multimedia requirements - App classes Typically sensitive to delay but can tolerate packet loss would cause minor glitches that can be concealed Data contains audio and video content continuous media three classes of applications Streaming Unidirectional Real-Time Interactive Real-Time 4 2 2003 Nguyen Chan Hung-Hanoi University of Technology 2 Application Classes 2 streaming Clients request audio video files from servers and pipeline reception over the network and display Interactive user can control operation similar to VCR pause resume fast forward rewind etc. Delay from client request until display start can be 1 to 10 seconds 4 2 2003 Nguyen Chan Hung-Hanoi University of Technology Application Classes 3 Unidirectional Real-Time similar to existing TV and radio stations but delivery on the network Non-interactive just listen view Interactive Real-Time Phone conversation or video conference More stringent delay requirement than streaming and Unidirectional because of real-time nature Video 150 msec acceptable Audio 150 msec good 400 msec acceptable 4 2 2003 Nguyen Chan Hung-Hanoi University of Technology 4 Challenges TCP UDP IP suite provides best-effort no guarantees on expectation or variance of packet delay Streaming applications delay of 5 to 10 seconds is typical and has been acceptable but performance deteriorate if links are congested transoceanic Real-Time Interactive requirements on delay and its jitter have been satisfied by over-provisioning providing plenty of bandwidth what will happen when the load increases . 4 2 2003 Nguyen Chan Hung-Hanoi University of Technology Challenges 2 Most router implementations use only .
