because of the current continuous progress of information society, people have increasing demand for data communication. since the tcp / ip protocol family seven mid launch, has become network the de facto standard communication protocol layer based on tcp / ip, the internet has become the largest and most important network. as the core of ip network devices have been widely used ever. ip network as the core equipment, the technology has become the key technology of information industry, the equipment itself in the data communications play an increasingly important role. at the same time as powerful equipment, and technical complexity, the manufacturers of the to achieve too much selectivity. as the core of the public network equipment, it is necessary to raise the minimum equipment standards requirements. therefore, to standardize on the device has its importance and necessity. on the standard device has been released as follows: yd/t1156-2001 " test specification - high- end "; yd/t1098-2001 " test specification - low-end s." definitions is working in the third layer of osi reference model?? network layer packet forwarding device. s forward packets to achieve the interconnection. although the can support multiple protocols (eg tcp / ip, ipx / spx, appletalk and other agreements), but the vast majority of s in our running tcp / ip protocol. s usually connect two or more ip subnets or point to point agreement by the identity of the logical port, at least one physical port. s receive packets according to the network layer address and the to maintain routing tables within the decision output and the next hop address, and rewrite the data link layer header forwarding packets. s routing tables to reflect the dynamic maintenance of the current network topology, and other s with the network to exchange routing and link information to maintain routing table. categories current classification of different s, various classifications have some relevance , but not entirely consistent. from the structural points, s can be divided into modular structure and non-modular structure, usually in the high-end s for the modular structure, low-end for non-modular structure. location from the network division of the can be divided into core s and access s. core s in the network center, high-end s typically require fast packet switching capabilities and high-speed network interface, usually modular structure; access s in the network edge, typically used in low-end s, the port and required relatively low strong access control. from the functional division of the can be divided into general-purpose s and dedicated s. general, generic to . dedicated s usually achieve a particular function on the interface, such as specialized hardware optimization, such as access s for access dial-up users, pstn interface and enhanced signaling capacity; vpn processing capacity and enhanced hardware encryption tunnel; broadband access into the , broadband interface number and types of stress. points from the performance, wire-speed s, and s can be divided into non-wire-speed s. wire-speed s are usually high-end s, can forward packets media rate; in the low-end s, wire-speed non-s, but the number of new broadband access also has wire-speed forwarding capability. in the development of standards, the can be divided from the ability to distinguish between: the high-end s and low-end s and other types of backplane switching capacity of more than 20gbit / s, packet switching capacity of more than 20mbit / s called high-end ; packet switching capacity of less than 1mbit / s low-end as a . the largest market share of cisco's case, high-end 12000 series s, 7500 series s for the low-end s, the following. obvious gap in the division: packet switching capacity of 1mbit / s over 20mbit / s does not refer to the following standards. in accordance with the standard series, should be mid-range specification. however, because there is no spec ial mid-range s, can refer to low-end s or high-end router, so no separate separate standards.
access point vs router
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