The development direction of exchange technology: from two layer exchange to adaptive Service Exchange

Ethernet switch as the physical embodiment of Ethernet switching technology has undergone great and profound changes. This article will review the development of the switch, and explain the future development direction of the exchange technology in the Adaptive Network (@Net)-Adaptive Business exchange.

Development history of Ethernet switching technology

Two-tier Exchange:

The exchange technology was born in the 80 's and was originally an improved version of the Multiport Network Bridge, which aims to continuously subdivide the LAN broadcast domain.

ATM Switching and routers:

In the middle of the 90 's, due to the rise of the campus network and the metropolitan Area Network, the two-layer switch has been deficient in broadcasting scale, geographical coverage and management, and started to introduce router or ATM switch to construct backbone network in the environment of large LAN, campus network and metropolitan Area network.

Gigabit three-layer exchange:

In the 1997 ~1998, two major technologies commercially changed the technology melee, namely Gigabit Ethernet and three-tier switching technology, especially the three-tier switch, which enabled Ethernet switches to be the core of a large park network that could replace routers. These two technologies gradually become the network-led, routers retreat to the WAN edge, ATM simulation declared out.

4~7 Layer Exchange:

Three-layer switch quickly commercial, soon emerged the concept of 4~7 layer Exchange, initially defined as the switch on the network message application recognition and QOS/ACL intelligent processing, and then rise to the content of the server load balancing, the ability of the ordinary switch can not be assumed, Therefore, the final development for the switch to achieve a simple message recognition and parameter settings processing, does not affect efficiency, and the use of dedicated Webswitch or Webswitch modules to achieve depth of the content exchange. Huawei's 3Com S8016 product is an earlier product that supports the technology.

Full Distributed packet forwarding:

The above three-layer or 4~7 layer Exchange in the initial development of the flow cache to achieve, with the network topology increasingly complex, the scale of explosive growth, the drawbacks of this technology is increasingly revealed. Especially after 2000 of red Code, worms, shock waves and other viruses against the network structure of attacks, resulting in large area of the switch paralysis, so that the crisis reached its peak. Leads to full distributed packet forwarding surfacing. This technology, originally supported by GSR, was eventually ported to the design of the three-tier switch. Huawei's Quidview switch is the early implementation of a full distributed packet-by-parcel Forwarding classic example, 2003 years later, the network deployed three-tier switches are basically the new architecture.

Multi-Service Exchange:

The overall performance of the switch has been greatly improved, but various business types in the network require differentiated services such as End-to-end SLAs, end-to-end security parameters, path control, and management requirements.

Multi-Service hosting includes the following key technologies: VLAN and VLAN switching, MPLS, IPV4/V6 dual stack, multicast switching, embedded security, traffic analysis, etc. Therefore, the traditional switch based on the need to overlay the support of these technologies, the typical example is the Huawei 3Com S6500 series products. Enhanced by this function, so that the switch has the ability to realize the End-to-end management control and differentiated service, this stage is a multiple service exchange, because it is superimposed on the traditional three-tier switching technology, so the key technology of multiple service exchange can be summed up as l3+ (enhanced three-layer switching technology).