The scalability of H.323-based video conferencing system is closely re lated to the architecture of gatekeeper (GK). A distributed H .323 gatekeeper architecture based on multiple zones was proposed, providing the solution for the deployment of multimedia video conferencing system on the large scale netwo rk. This architecture did not only conquer the drawback of centralized architect ure and hierarchical architecture, but could balance the load between gatekeeper s. Design of GK-level signaling message routing based on alias format was used t o solve the communication problem between endpoints registered in different zone s. In the zone, the centralized architecture was adopted and the main-GK manage d the slave-GKs. Balancing load factor algorithm(BLFA) was presented to balance the load between gatekeepers.
 ITU-T Recommendation H.323 V2 (1998),Packet-based mu ltimedia communication systems[S]
Radhika R Roy. Framework for H.323 inter-gatekeeper communications . APC -1385 Q.11-14/16,1998
���ֳ�,���Ķ�. ����ʵ����������Ͳ��Ե��о�(��)[J]. �����ʵ��ѧѧ��,2000,23(2):62��66 Hao Youchao,Wang Wendong. Some problems and strategies in the implementation of gatekeeper[J]. Journal of Beijing University of Posts and Telecomm University ,2000,23(2):62-66(in Chinese)
����,�ŵ���,�Զ�ƽ,��. �ֲ�ʽ����չ����ϵͳ�������ʵ��[J]. ���������,2004,15(30):97-99 Zhang Xiao,Zhang Deyun,Zhao Dongping,et al. Design and implementation of a hi erarchical and scalable gatekeeper system[J]. Computer Engineering,2004,15( 30):97-99(in Chinese)
Li Rui,Yu Zhanwu,Wang Hao. Research on multi-zone and hierarch ical routing for video gatekeeper based on agent Proceedings of the 2005 Systems Communications. Montreal:IEEE Computer Society Conference Publishing S ervices,2005:159-164
Radhika R Roy. Distributed gatekeeper architecture for H.323-based multi media telephony Proceedings of the 24th Conference on Local Computer Net works. Boston:Lowell Massachusetts,1999:73-76