Multicast solution in IRF Network (1)

With the rapid development of information technology, the overwhelming network has gradually become an indispensable part of people's life and work, in particular, modern young people put more learning and entertainment time into computer networks, and computer networks have gradually become the main way for people to learn and entertain. How to provide users with a high-bandwidth, high-reliability, high-performance multimedia video service has become a major challenge facing service providers.

In traditional multimedia services, each user connects to the server through unicast. When the number of VOD users increases, the number of connections established on the server also increases, leading to abnormal busy servers providing services. A high-performance server can provide multimedia services to many users. Repeated high-bandwidth multimedia data increases network traffic and causes serious network congestion. In this case, the multicast routing protocol solves the disadvantages of running multimedia services in Unicast mode and provides technical support for transmitting multimedia services across the network. Although it is feasible to provide multimedia services in this new way of multicast, the current network reliability is low, the network performance is not high, the investment is large, and other adverse factors, as a result, it is impossible to provide customers with high-quality multicast services at a low cost, which greatly affects the promotion and popularization of multicast services.

Today's multicast networks have the following features:

High Investment Reliability

High network reliability means that the system exchanges a limited price for the maximum running time, minimizing the loss of service interruption caused by faults. In System 1, hardware or software faults must be minimized, and backup of important resources must be provided. When a fault is about to occur, the system can quickly transfer the affected tasks to the backup resources to continue providing services.

High network reliability is generally achieved at three levels: system, component, and link. System-level high availability requires that the network topology must have redundant nodes and backup designs. For example, you can configure multiple switches on a network node and specify one of them as the primary switch, then, VRPP technology is used to back up multiple vswitches. component-level High Availability focuses on the network devices themselves, requiring network devices to have redundant components and Hot Backup mechanisms, for example, backup components such as dual-power supply and dual-master are required. Link-level high availability requires that the transmission line must be backed up. If the main data path is interrupted, the backup line will be quickly enabled, in terms of link redundancy, STP, RSTP, and MSTP are collectively referred to as STP) and link aggregation technologies.

After the above technologies are adopted, these devices will not participate in the data forwarding of the entire network during most of the time of network operation. It is an idle redundant device or link to Ensure network reliability, it is a kind of high reliability in exchange for high investment.

Single Port Extension

The diversity and uncertainty of users impose another requirement on service providers. They must use flexible networking methods to cope with unpredictable changes in customer groups and reduce risks. When the number of users increases, service providers blindly increase the number of devices and increase the capacity. Because the newly added vswitch and the original vswitch do not constitute a whole, the performance of the network device decreases, the network management is more complex, and the normal operation of the entire network is affected.

Complex Network Management

In today's networking mode, you can manage network devices in multiple ways. From the bandwidth perspective, it can be divided into in-band management and out-of-band management. In-band management includes WEB and network management software SNMP) and remote TELNET. Out-of-band management includes management through the control port of the device.

Because in-band management runs in its own network, it is used more frequently, but the device must have a unique IP address. In the traditional mode, in addition to some stacking methods, most devices that are managed by the network must be equipped with IP addresses. This may not be a small number of core switches, but for a large number of edge switches, not only increases the complexity of configuration, but also occupies a large amount of address space. Even for switches that work in the stack mode using an IP address, the management interface still shows the switches that are stacked together, rather than a real whole, the specific configuration is still separately configured for each vswitch.

Low investment efficiency

In today's exchange mode, the Network Center is a rack-mounted switch, and the edge is a box switch. Because existing technologies cannot solve the load balancing problem while implementing redundancy, when users buy equipment in the initial stage, the performance of a single center switch must meet the data stream forwarding requirements of the whole network. Considering the future development, the performance requirements for devices are much higher than the actual requirements for network construction. In this way, the central device needs to purchase the entire rack at a time, which increases the cost of networking. In terms of reliability, the same equipment needs to be purchased only for backup, greatly reducing the investment efficiency. When the performance of the central device cannot meet the development requirements after that day, you can only purchase new core devices. In this case, the performance of the original device in the center may be insufficient, at the edge, performance is too high. Investment Protection is not good.