Convergence of two networking technologies of ATM and Gigabit Ethernet

The selection of network backbone technology directly influences the performance and future expansion and upgrade of networks system, and should be fully demonstrated and carefully chosen. In the previous years of network construction, many units have chosen ATM as the backbone of the network technology. Gigabit Ethernet is a technology developed in recent years, compared with Fast Ethernet, provides a higher and faster transmission speed, and has a better third-tier switching capabilities, to manage higher bandwidth and flow, its technology is simpler than ATM, and reasonable price. The corresponding Gigabit Ethernet standards have been introduced, so the current gigabit Ethernet is the main direction of LAN development. Many units in the network expansion and upgrade, the choice of the gigabit Ethernet as a backbone technology. However, in order to protect the investment and effectively utilize the original network equipment, it involves the interface between ATM and Gigabit Ethernet, this paper introduces the solution of the problem with our practical experience.

Our campus network in the first phase of construction, the backbone of the use of ATM technology, installed a certain number of network equipment, the backbone of the switch using the 3COM corebilder 7000HD, the current equipment is working normally. In the second phase of construction, the backbone of the use of Gigabit Ethernet technology, in order to protect the campus network Phase I Project investment, the original ATM and Gigabit Ethernet interface between the following several ways: (learning computer)

1, Gigabit backbone switch to select Cisco's Catalyst 6509, it is the most suitable for a certain size of the campus network as the backbone of the three-tier switch, but it can only configure the 622M interface module, need to provide 622M interface on Corebilder 700HD (need to buy again), The two end as Les, the other end as a LEC, you can realize the information points between two systems in the same subnet, to achieve the convergence of both networking technology.

2, the use of Support 155M interface Cisco three-layer switch, optional catalyst 8540, because 8540 port density is small (such as gigabit module only two ports), its high cost (according to our system needs to configure, than the catalyst 6509 price expensive 50,000 U.S. dollars).

3, a compromise approach is to sacrifice management convenience, so that different systems (ATM and Ethernet) information points in different subnets. The two systems are connected by a Cisco Catalyst 2824M (configured with Gigabit Ethernet modules and 155M ATM fibre modules), which are parallel to each other.

Ethernet user data is exchanged through the Catalyst 6509 switch, and the data exchanged with ATM network users is Corebuilder 7000HD LAN emulation. The Ethernet data is translated into ATM's signaling form via lane, and the destination site is reached through an ATM network. The destination site also reaches the destination via an ATM network. The destination site is also translated into Ethernet data via Atm-fame. Of course, Lane's service must be provided by Corebuilder 7000HD. Corebuilder 7000HD should provide les/lecs/lec/bus and so on.

All of the above 3 options are feasible, choose which one can be based on demand and funding. Because of the lower cost of the third scheme, and can meet the demand, so we have adopted. Considering that the mutual access between Gigabit Ethernet and ATM networks needs to be converted multiple times, in this way, the performance of the information points between the Ethernet subnet and the ATM subnet will be affected, so the existing ATM switches are properly concentrated in several construction objects, taking into account that the ATM network transmission distance is longer than Gigabit Ethernet , the ATM switch is concentrated in a building with a far distance from the center of the network, fewer information points and less traffic.