subject: Multi-layer switching network to the router "intelligent" up - routers, switches, servers - Communications Industry [print this page] Multi-layer switching network to the router "intelligent" up - routers, switches, servers - Communications Industry
Today's world, increasing the degree of the network, between people and equipment Communicate , Changes in variety.
Some types of communication already well known, such as IP voice (VoIP), digital images, multicast, video on demand, peer file sharing, remote video conferencing and so on. However, all these applications have one common characteristic is that the demand for bandwidth can be "greedy" word to describe.
The long run, the bandwidth itself is not always used. Therefore, the underlying network infrastructure, intelligent "equipment", that is, Switch And Router Must assume an intelligent way to keep up with the pace of the difficult task of bandwidth requirements. Such as video and digital X-ray applications such as always require larger, more intelligent "transmission Pipeline "The VoIP application requires low latency or response time and the same transfer rate. The mid-90s, with the decline of the traditional switch, people began to race the development of faster, smarter switches and routers. Silicon Valley a group of genius saw opportunity in this market, thus, in one known as "multi-layer exchange routing" new invention based on the concept of network hardware and related software. and the only software-based routers were compared These new "smart" switches / routers to provide faster speeds and shorter delays, while the ability to multi-functional network equipment together.
The original, when the need to increase network bandwidth, network administrators, often through the network design to avoid re-occurrence of the bottleneck router. Service Quite often not through the router, re-installed in a place closer to the user. In large enterprises, the user typically through a router is divided into a number of smaller interconnected network (subnet). This division is usually in accordance with local, run the application type, the amount of data required and Security Aspects to carry out. For example, the financial sector is often all Cloth Home in their own group, because to do so in order to effectively protect the company's financial records, not taking into account the bandwidth used. The VoIP phones are often placed in their own networks, the reason is that it can bypass the bottlenecks of traditional routers.
When the computer needs its own local network, to communicate with other computers, to data Package Sent to the group outside, they must first send packets to the nearest router. Routers to provide the company with Internet connectivity and security between the borders, and the connection between internal groups (internal network).
Traditional routers use only when absolutely necessary, such as remote offices connected via WAN to connect to the Internet or isolated companies with high bandwidth requirements of the group. Traditional routers expensive, is still the case, and compared with the original design, no major progress, the use of components and a standard PC Similar, and the use of multiple interface cards running dedicated software.
Contrast, multilayer switch router to router all the features of the traditional focus on a specific IC (AS IC ) On. ASIC than the traditional router CPU Cheap, and often distributed across multiple network ports. Now, a typical switch / router in one device may be included in the 50 ASIC, can support hundreds of interfaces. In addition, the new ASIC allows intelligent switch / router all the ports in the fastest speed forwarding of data, regardless of what type of network traffic, can be said that they are the actual interface speed (often referred to as wire-speed) forward data. Currently, the market for enterprise local area network (LAN) of new switch / router in a single interface Zhongwan Zhao bits per second bandwidth (OC-192) forwarding data.
Out of the old times, into the exchange of new world
The use of a centralized architecture, traditional routers, a general lack of scalability. Traditional router, all packets reach the router must be sent to a processing area, so the number of interfaces you have more load on the system the more serious, resulting in excessive resource occupation. This greatly limits the network provides services such as VoIP.
When a router uses a centralized architecture to deal with traffic beyond its capacity, it will begin to discard packets. When the network application or the computer can not receive response information, they will send more data packets, trying to resume the session. This situation becomes worse, because it is prone to cross-conversation overload. This case, the router overload based on applications, users, or network priority objectives / source address and selectively discard packets. Clearly, we need a new approach to meet traffic growth requirements.
Years, traditional routers, there have been significant speed increase, but still not enough to keep up with the pace of powerful applications. For example, they now can be transmitted per second, nearly one million packets. But consider a per second to send 1,488,000 packets (p ps ), And to 1,488,000 pps rate of receiving data packets Gigabit Ethernet interfaces 2 Gigabit Ethernet ports can easily overload the system. In contrast is the multi-layer switch / router to forward packets at wire speed, and the exchange of existing ASIC in a distributed manner, allowing the system efficiently transport traffic.
These new switches / routers use a new network design and management. Today in achieving the wire-speed forwarding, blocking point can be effectively eliminated, the user can further the distance from the data, and not worry about performance degradation. Our stock is mentioned in the previous example can now connect to a few floors away with their hundreds of miles away or servers or network data, depending on the specific distance from the switch / router supports interface types and the use of Copper Cable or fiber types. In addition, the new IP and Ethernet routers optimized easier to manage, managers only spend very little time to make the network to keep pace with new applications. Foundry's BigIron chassis type as the products, they can simply transfer all traffic from the application of the same time, you can add more modules to meet the increased capacity and speed requirements.
Network traffic to determine the type and capacity, today's ASIC built a new data packet sampling
