Discussion Of Bearer Technology For IPTV Services

IPTV is a kind of telecommunication which is carrying on IP networks. According to function characteristics,it can be divided into streaming media, communications and information services, games, etc. One of streaming media is including vod video and audio broadcast. Communication business is including video communication and messages. Streaming media service of high bandwidth demand for real-time communication. IPTV service and usually Internet data business is quite different. In bandwidth and QoS, reliability, safety aspects of bearing network has high technical requirements. Now, carriers' IP network faces great challenge on bandwidth QoS reliability and safety for IPTV service.This article studies how to support IPTV on existing IP bearing network. Firstly, the article analysis the requirement for IPTV network, according to cuatomers bandwideth,network distribution and QoS, bring forward that every customer need the bandwidth to 4Mbit/s or more. QoS requirements of IP TV services on end to end IP bearer network are different.And then a deep research is made on IP related technologies, including IP QoS of three kinds of models, IP QoS realization means, MPLS VPN, multicast technology and realization means.Secondly, the article introduces the level structure and IP QoS deployment strategies of MAN.The deployment strategies is including rate limiting for access port, classification and tag for access port,queue scheduling, bandwidth reservation,and QoS for MPLS service.And the article show that the bottlenecks of MAN lies in the capabilities for end-to-end network QoS guarantees which facing to business and the capabilities for multicast.On the basis,the article gives the solution for IPTV service canrring on this MAN.The solution is divided into two parts,live broadcast and VOD.In the solution of live broadcast,CN2 connect province center with city centers in VLL,one of MPLS L2 VPN.And MAN connect province center with CPE in MPLS L3 VPN.The distribution of live broadcast media stream deploys unicast means. DiffServ is used in access layer to customer layer.VLANs are deployed to realize distinguish of different service,according to the VLAN planning.BRAS and convergence switch should also enable varieties of sub-interface. VLAN planning of five types of access are detailed. In the solution of VOD,the media stream are shown that how to be distributed from source to provice center, to MAN POP point,and to set top box.Lastly,the article show the data of QoS test in MAN and customers.The test verifies that the solution satisfies the need of IPTV carrying on MAN.