How to choose the third layer switch correctly for enterprises

Third-tier switches have a lot to learn from the place, here we mainly introduce how to choose the third layer switch, the third layer of switches present a strong growth trend, is replacing routers in the LAN, its huge market potential is attracting a large number of domestic and foreign manufacturers to join the competition. It is gratifying that the domestic manufacturers in the key technology has developed their own ASIC chip and network management software, so that users in the choice of brands to provide a broad space.





at present, the main domestic market manufacturers have Cisco, 3Com, Annette, Extreme, Fountry, Avaya, Nortel, Entersys, D-link, SVA, Shenzhou Digital Network, Huawei, the same-side network, Tsinghua and Tcl and so on. In the face of such a colorful brand, users in the choice of what aspects to start is the problem to be solved. For the choice of the third layer switch, because the network structure and application of different users will vary, so the emphasis on choosing the third layer switch is different. But for users, generally pay attention to the following aspects.





1. Pay attention to the full configuration of the same throughput as any electronic product, when you select a third tier switch, you first need to analyze the performance metrics for each product, but with many technical metrics such as switching capacity (Gbps), backplane bandwidth (Gbps), processing power (MPPs), throughput (MPPs), you'd better hold on to The "throughput at full configuration" metric, because other technical metrics users typically do not have the ability to measure, only the throughput is an indicator that users can directly measure and verify using test instruments such as smart bits and ixia.





2. The switch technology of distributed superior to centralized different brand is different, which can be divided into two kinds: centralized type and distributed type. The traditional bus-type switching structure module is centralized, and the modern Exchange matrix module is distributed. Because of the increasing amount of audio, video and data in the intranet, the requirement of the switch processing ability is more and more high, in order to realize high speed non-blocking switching in the high port density condition, it is a wise choice to adopt the distributed third layer switch. Because the bus-type switch module can not avoid the conflict in the Ethernet environment, the matrix type avoids the conflict phenomenon of the port exchange.





3. Concern delay and delay Jitter Index enterprise intranet is almost all high-speed LAN, one of the purposes is for audio and video and other large-capacity multimedia data transmission, and these large-capacity multimedia packets most taboo due to long delay and packet loss makes information transmission jitter. Some traditional centralized switches have a latency of up to 2ms, while some modern distributed switches have a time lag of about 10ms. The reason for the high delay is usually the switching structure of the blocking design and the overuse buffer, so the attention delay actually needs to focus on the module structure of the product.





4. Stable performance third-tier switches for the backbone and convergence layer, if the performance is not stable, it will affect the network system of most hosts, or even the entire network system. Therefore, only the stable third layer switch is the guarantee of continuous, reliable, safe and normal operation of the network system. Of course, performance stability looks abstract, and seems to require historical testing to be persuasive. In fact, because the performance of equipment is actually through a number of basic technical indicators and market reputation to achieve. As a result, you can determine through throughput, latency, drop frame rate, Address table depth, line-end blocking, and multiple-function metrics, as well as market application surveys.





5. As the third layer switch of network core equipment, security is the important object of hacker attack, which requires that the third layer switch should be included in the scope of network security protection. Of course, the "safe and reliable" here should include software and hardware for the third tier switch. Therefore, from the "security", it is necessary to have a third tier switch with excellent performance and no security vulnerabilities firewall capabilities. From the "reliable" view, because of the objective of any product can not guarantee its failure, and the failure to quickly switch to a good device is a need for concern. In addition, redundancy can be considered on the hardware, such as the power supply, management module and port and other important components support redundancy, which is especially important for users with high security and reliability requirements, such as telecommunications, finance and so on. There is the heat dissipation mode, such as cooling fan settings are reasonable and so on. Finally, for the broadband operators, the authentication function is also an important aspect of the investigation. Before the switch is for the enterprise use, on the net directly connected out, do not need certification. and broadband operators need to verify that the user is on record. User access to the Internet, a window appears, enter the user name and password to pass authentication, so the broadband operators of the third layer of switches should also support a number of special protocols such as 802.1X, to achieve certification.





6. Full-featured products not only to meet the existing needs, but also to meet the needs of the next period of time, so as to give users a value-added space. If the company employees increase, you can plug in the module to expand without eliminating the original equipment. There are also features, such as multicast, QoS, Port trunking, 802.1d spanning trees (spanning tree), and whether to support RIP, OSPF, and other routing protocols, which are important for third-tier switches. For example, in the VOD application, if a group of users on Demand for a program at the same time, the multicast protocol can ensure that the switch in high-density video streaming on demand very smooth data processing, on the contrary, if the switch does not support multicast protocol, the bandwidth occupied is quite large. Again, such as the QoS function can be divided into different levels according to the different needs of users, can make the broadband operators by Port Flowmeter charges, thus providing different services for different users. Also, access list functionality. If the VLAN is partitioned at the access layer, the different VLAN users cannot communicate because this is based on the second-tier VLAN. If you want to communicate, you must go through the third layer.





such as the financial department and the marketing department, generally do not contact, if the user needs to access, then the network administrator through the third layer of the switch to a simple command-line settings, so that the normal communication between the VLAN, which is the access list function. It is a function of porting from a router to a third-tier switch to enable one-way or two-way communication between different VLANs. If you find that an external IP address always sends unwanted packets to your network, you can set it in the access list to prevent it from sending packets. In addition, in the service, product ease of use and cost-effective aspects are also the focus of the object of investigation.