Multicast transmission method based on virtual distribution net in network

Abstract

The method comprises: establishing a virtual allocation network for each multicast session in network; the virtual allocation network is composed of the user's host machine participating the multicast session and the selected nodes; said host machine and nodes are connected through virtual link and have unique ID; in the virtual allocation network, when sending service data, the sending host machine sets IP address of receiving host machine as IP address ID of virtual allocation network; each node on the virtual allocation network allocates IP packets until the IP packets are transmitted to all receiving host machine in the virtual allocation network.

Description

technical field [0001] The invention belongs to the technical field of computer communication, in particular to a multicast (Multicast) transmission method in an IP network. Background technique [0002] An IP network is a computer network that uses the IP protocol (Internet Protocol) for communication. The IP protocol can provide three communication methods between hosts: unicast, broadcast and multicast. Among them, unicast is a point-to-point communication mode between two hosts. Broadcast means that a data packet sent by a host can reach all hosts in a broadcast domain. Multicast means that a data packet sent by a host can reach a group of hosts in the network. Unlike broadcast, multicast will not transmit data packets to hosts outside the group. [0003] There are mainly two types of nodes in an IP network: a host (Host) node and a router (Router) node. Host nodes are located at the edge of the network and do not undertake the function of data packet forwarding, suc...

AI Technical Summary

Problems solved by technology

However, IP multicast has not been deployed on a large scale by operators, and currently almost no IP multicast-based services are widely used by users

The reason for this situation is that there are still many problems in IP multicast. These problems come from the open business model on the one hand and the transmission mechanism of multicast data packets on the other hand.

If one of the nodes does not support multicast, the distribution tree cannot be established

However, the Internet network is not a unified management network. It is impossible for each operator to upgrade its own network at the same time, and it is also impossible to abandon all existing equipment at once. Broadcasting business has become an unrealistic idea

[0011] Second, poor adaptability to network dynamic changes

[0012] Third, bidirectional transmission is not supported

[0013] Fourth, it is difficult to guarantee the performance of multi-source multicast

However, for services with multiple source nodes, such as video conferencing, in order to ensure performance, only one distribution tree can be established for each source node, but this approach will greatly increase the distribution tree status that needs to be maintained in the network. When users change, all distribution trees must be updated accordingly, which also increases the difficulty and complexity of multicast service management

[0014] Fifth, lack of control mechanism for multicast packet delivery

[0018] First of all, the performance of each user host is limited, the access bandwidth is limited, and the online time is unstable, which means that it is impossible for multicast data packets to achieve efficient and reliable forwarding similar to router hardware.

Secondly, the user host cannot understand the underlying network topology, so it is impossible to form an optimal forwarding path, which will occupy more network resources, especially precious access network bandwidth resources, and cannot guarantee real-time and synchronization of services Performance, not conducive to interactive or live broadcast services

Therefore, application layer multicast cannot provide a carrier-class service support, and can only be used as a supplement to future network layer multicast

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