1. D EPT. OF I NFO. & C OMM., GIST AG connect: Toward better connectivity for the AG 19 th APAN Bangkok Meeting (2005. 1. 25) Namgon Kim and JongWon Kim Networked Media Laboratory Dept. of Information & Communications Gwangju Institute of Science & Technology (GIST) jongwon@netmedia.gist.ac.kr http://ace.netmedia.gist.ac.kr/

2. D EPT. OF I NFO. & C OMM., GIST Contents Access Grid (AG) AG Connectivity Problems Unicast networks Networks behind Firewall and NAT Low capacity nodes Connectivity Solution for High-Quality Video Structure of High-Quality Video for AG Modification of AG Structure Modified QuickBridge Implemented Result Conclusion

3. D EPT. OF I NFO. & C OMM., GIST Access Grid (AG) Support group-to-group interaction across the Grid Access Grid does for people what the computational Grid does for machines Much more than teleconferencing, if possible at commodity prices To enable groups of people to interact with Grid resources and to use the Grid technology to support group to group collaboration at a distance Distributed Lectures and seminars Remote participation in panel discussions Virtual site visits meetings Complex distributed grid based demonstrations

4. D EPT. OF I NFO. & C OMM., GIST AG Connectivity Problems (1/3) Multicast Connectivity Access Grid uses multicast for multimedia delivery Multicast is bandwidth efficient Multicast-disabled networks Unicast networks Networks under ISP’s control Multicast failures compromise the usability of the Access Grid

5. D EPT. OF I NFO. & C OMM., GIST AG Connectivity Problems (2/3) Firewall and NAT transition Firewall Packet filtering and Protocol end point A multicast packet sent over the Internet will never be seen on the intranet, unless such packets are explicitly relayed by the firewall NAT (Network Address Translation) Unidirectional connection initiation only –Only hosts behind NAT can initiate the connection

6. D EPT. OF I NFO. & C OMM., GIST AG Connectivity Problems (3/3) Problems due to low capacity for data System is under multicast-enabled network But due to lack of capacity, have difficulties in handling data Nodes under Low network bandwidth Nodes in small network bandwidth can not receive multimedia data Nodes with Low performance System Nodes with poor system performance can not process received data

7. D EPT. OF I NFO. & C OMM., GIST AG Connector Vision of AG Connector A solution for all these connectivity problems 1.AG Connector for Unicast Nodes 2.AG Connector for Networks behind firewall 3.AG Connector as a proxy For users with low system performance For users with low network bandwidth

8. D EPT. OF I NFO. & C OMM., GIST Connectivity Solutions for High-Quality Video Modify QuickBridge to support AG with High-Quality Video A connectivity solution for AG with High-Quality Video AG with High-Quality Video Limitation of current Access Grid Toolkit (2.1.x) Low-resolution VIC-based video (300Kbps CIF sized image) High-Quality video services for Access Grid Toolkit is developed to promote advanced collaboration environment HDV (1280x720)/DV(720x480) support Motivation Current QuickBridge of AG is not applicable to AG with High-Quality Video AG with High-Quality Video is using two multicast addresses Session multicast address Video multicast address Modify QuickBridge to provide connectivity solution for AG with High- Quality Video

9. D EPT. OF I NFO. & C OMM., GIST Structure of High-Quality Video for AG Motivation Limitation of existing video services in supporting high-quality video Features Versatile Video Format Support Multimedia Session Management Enable AGTk to support various video formats via an unified interface Multicast-enabled Network AG Node HDV DV Stereo Versatile Video Formats

10. D EPT. OF I NFO. & C OMM., GIST Flexible Multicast Address Allocation A Shared multicast address for every Video Consumer Service Session multicast address Video Consumer service gets video stream list from session multicast address A unique multicast address per each Video Producer Service Video multicast address Let each AG node can receive video streams selectively. Can allow the sender share multicast address, if it is required Multicast 1 Video stream 1Video stream 2 Video stream 3 Multicast 2 Multicast 3 Video stream 4 Multicast 4 Select Video 1, 3

11. D EPT. OF I NFO. & C OMM., GIST Lack of Multicast Bridge Service To utilize flexible multicast address allocation, High-Quality Video for AG modifies structure of AG Uses more than two multicast addresses for one High-Quality Video Session Modified Structure of High-Quality Video for AG isn’t compatible with current AG Structure Current AG uses only one multicast address for a session QuickBridge is only for one shared multicast address To provide Multicast Bridge Service, AG must store two kinds of info. One for session multicast address, the other for video multicast address Need to modify current AG’s structure to provide storage for multiple multicast addresses

12. D EPT. OF I NFO. & C OMM., GIST Modification of AG Structure EVS (Extended Video Service) is the implementation of High-quality video service Modification of Access Grid Modify EVS Stream Description to store these two bridges’ information Execute video application using information received from SAP (Session Announcement Protocol) Provide a way for high-quality video producer to keep its video multicast address Modification of QuickBridge Modify QuickBridge of AG to create multicast bridge for each multicast address Stores mapping information between multicast address and unicast address Multicast Bridge for session multicast address does translation of SAP message Translate SAP message to fit the connection type of consumer

13. D EPT. OF I NFO. & C OMM., GIST EVS Stream Description Modify EVS Stream Description to store Multicast Bridge information for EVS Stream Provide a way for high-quality video producer to keep its video multicast address Bridge Server Modify Bridge Server to create Bridge for two multicast addresses of EVS

14. D EPT. OF I NFO. & C OMM., GIST Modified QuickBridge (1/2) Bridge Server stores Bridge information when it makes a new Bridge Information about the relation between multicast address and unicast address Unicast Mappings Multicast Mappings Bridge for Session multicast address Analyzes session information, and transforms it according to the network connection type of EVCS For a EVCS which uses multicast bridge, Bridge sends all information as unicast form For a EVCS which uses multicast, Bridge sends all information as multicast form

15. D EPT. OF I NFO. & C OMM., GIST Modified QuickBridge (2/2)

16. D EPT. OF I NFO. & C OMM., GIST Implemented Result

17. D EPT. OF I NFO. & C OMM., GIST Conclusion Connectivity Solution for High-Quality Video Modify Quick Bridge to provide multicast bridge to High-Quality Video for AG Access Grid Modify EVS Stream Description to store these two bridges’ information Execute video application using information received from SAP QuickBridge Create multicast bridge for each multicast address Translate SAP message to fit the connection type of consumer Future Work Implement AG Connector Use tunneling with Encapsulation Provide connection with AG by Shared Application

18. D EPT. OF I NFO. & C OMM., GIST Thank you! Send Inquiry to ace@netmedia.gist.ac.krace@netmedia.gist.ac.kr http://ace.netmedia.gist.ac.kr/ Gwangju Institute of Science & Technology