Comparative analysis of the advantages and disadvantages of the three optical network cabling technologies

Comparative analysis of the advantages and disadvantages of the three optical network cabling technologies

1: FDDI/CDDI (fiber/copper distributed data interface)

This is a mature, non-carrier-sensing, 100M bandwidth-sharing network technology. Adopting the token delivery service strategy, the primary and secondary rings are connected between network devices. When network lines or network devices fail, they have strong self-reconfiguration capabilities. At the same time, its station management (SMT) function is very powerful and suitable for backbone networks. However, its technical difficulty is high, the price is expensive, and its scalability is poor. It is in a circular layout and is not compatible with ATM.

2: ATM (Asynchronous Transfer Mode)

This is an advanced asynchronous mode based on an optical fiber transmission system, a statistical multiplexing technique, and a short cell switching technology. It directly supports multimedia transmissions such as data, video, and audio. The rate is fairly fast (155M, 622M achieved). Due to the asynchronous mode, the total efficiency is quite high and it is suitable for the backbone grid. However, it is still a controversial technology. Many standards have yet to be improved. The interoperability and versatility of products from different manufacturers need to be further improved.

3: FASTETHERNET (Fast Ethernet)

Today's high-speed Ethernet technologies generally include two types: 100MVG-ANYLAN and 100M-T. The main point here is the latter - fast switched Ethernet. Although 100MAG-ANYLAN provides multimedia functions, it has poor compatibility, high price, and high complexity. It is not considered here. 100BASE-T is an improved variant of 10BASE-T. It is based on the original method of dividing the grid into several network segments, splitting the collision domain, and adopting buffer switching to greatly increase the transmission rate and transmission efficiency on the grid.

Fast Ethernet is practical (compatible with the original Ethernet, rich in software and hardware), advanced (fast -100MBPS), easy to upgrade (convenient to the ATM or faster grid conversion), scalability is good (through the interconnection device , switches, routers are easy to expand), openness is good (software and hardware protocols are open), cheaper (compared to ATM, FDDI), support more manufacturers (supported by large companies such as Intel, Sun, 3com, Bay, Accton, etc.) Features. For multimedia grid applications, Fast Ethernet can also meet the requirements.

Although the effective distance between Ethernet mesh devices is shorter (100 meters) and is suitable for small LANs at the department level, it is possible to use fiber optic converters and fiber optics to extend the transmission distance. Fast Ethernet has excellent scalability. Using switching hubs and ordinary hubs, the expansion of the number of users has no effect on the grid (it can be expanded when it is in use), which facilitates future subnet access.

Based on the above analysis, combined with the main points of the integrated wiring system and grid technology, here are three integrated wiring solutions.

First, the use of full twisted pair structure cabling solutions (fast Ethernet technology)

This kind of scheme is that the entire wiring system (vertical subsystem, horizontal subsystem, work area subsystem, equipment room subsystem, wiring closet subsystem) adopts all five types of twisted pairs, and the network technology adopts Fast Ethernet technology.

Advantages: Costly wiring, cheap grid equipment, and easy management, Fast Ethernet technology is quite mature, and its exchange is carried out on the second floor without manual intervention.

Disadvantages: If the floor is high, this may lead to the wiring length of some residence points exceeding 100 meters. It is known that according to the wiring principle, twisted-pair cables generally cannot exceed 100 meters, which will cause signal attenuation and distortion. Secondly, since all the wiring is radiated from the central engine room to other floors through the vertical subsystem, the requirements for shafts are higher. The second is that the full twisted-pair structure is difficult to upgrade to ATM technology or Gigabit Ethernet technology. ATM technology and Gigabit Ethernet technology need to use single-mode/multi-mode fiber to connect to form the trunk.

Comparative analysis of the advantages and disadvantages of the three optical network cabling technologies