Network Interconnection and a comprehensive explanation of LAN switches and router devices

Vswitches and vrouters are very important devices in the network. Here we mainly introduce network interconnection and LAN switches and vro devices. The CLIP solution only supports the TCP/IP protocol, but there are many network-layer protocols running on the existing network, such as IP, IPX, Appletalk, DECnet, Banyan, and Vines. The same network layer protocol must be used to connect an ATM network to multiple existing LAN networks.

1. Basic Principle of LANE Simulation

As the name suggests, LANEEmulated LAN) is used to simulate a LAN on an ATM network, and the obtained LAN is called ELANEmulated LAN ). The LANE Protocol defines a mechanism for simulating the IEEE 802.3 Ethernet or IEEE 802.5 licensing ring network. The LANE Protocol defines the same interface as the service provided by the existing LAN to the network layer. The data transmitted in the ATM network is encapsulated in the corresponding lan mac group format. Simulate a traditional LAN on the ATM network, and connect multiple traditional LAN and terminal devices through the ATM network. Create a new LAN on the ATM network, and the communication behavior between these LAN points is exactly the same as that of the traditional LAN. LAN simulation hides the switch and router structure of the LAN, and the LAN terminal does not feel the existence of the ATM network. Therefore, the advantages of the ATM network can be used without modifying the hardware and software of the terminal device.

The simulation protocol is mainly implemented on the ATM host and the atm lan bridge. An atm lan Bridge is a converter between a LAN and an ATM. It uses the ALL5 protocol to adapt LAN data. It is used to generate an ATM cell, or reorganize an ATM Cell to restore the data frame of the LAN. The LAN simulation function is added between the ATM Adaptation Layer and the high-level protocol to enable the ATM host to simulate the behavior of traditional LAN devices and communicate with the LAN. Atm lane is designed for LAN access. for traditional IP terminals, the ATM network is like a LAN, which contains several IP subnets connected by routers.

In ELAN, the LANE Protocol defines the same business interface as the existing LAN for the high-level layer, so that the data transmitted through the ATM network can still be encapsulated in the corresponding lan mac information package format. The LANE protocol is a solution that makes all aspects of the ATM network, including connection establishment, cell division, and restructuring SAR, completely transparent to the nodes, that is to say, the LAN node connected to the ATM network does not have to care about the above operations in the ATM network. LANE enables any higher-level network protocol to run on an ATM network without modification, because the LANE Protocol provides network-layer drivers with the same service interfaces as the existing MAC protocol, such as the network drive interface specification NDLS or the Open Data Link Interface ODI Driver Interface ), no modifications are required to these drivers.

The LANE Protocol specifies the operation of a single simulation LANELAN. An ATM can have multiple Elans at the same time. Each ELAN simulates an Ethernet network or a ring-based network. The LANE Protocol needs to run on the following two types of ATM devices:

ATM network interface card NIC)

The atm nic (also known as the atm nic) executes the LANE Protocol to connect the LAN terminal to the ATM network, instead, connect to the atm lan switches and routers that support the LANE Protocol or the ATM routers that support the LANE Protocol described below ). In the connected terminal system, the ATM Nic provides service interfaces for running the LAN high-level protocol on the ATM layer. In this way, the terminal system connected to the ATM network can continue to use the original high-level network protocol for communication. Of course, after connecting to the ATM network, the terminal system can enjoy the advantages of the ATM network, such as high bandwidth support and flexible WAN applications.

Network Interconnection and LAN switches and router devices

This type of equipment mainly refers to the LAN vswitch and vro connected to the ATM. It is used to connect various LAN nodes or connect to the LAN Terminal System of the ATM network through an ATM Nic supporting the LANE Protocol, of course, you can also directly connect to an ATM host system installed with an ATM network card. After a LAN device is connected to an atm lan switch and a router, it is essentially equivalent to establishing a bridge between the ATM network and the LAN network. The LANE Protocol is equivalent to a bridge protocol, it changes the MAC address of a device in the LAN network to an ATM address, so that the LAN device can still be recognized after being connected to the ATM network.

2. LANE network composition

LANE is based on the Client/Server mode). a lane Server can be connected to multiple LANE clients. LANE supports Multi-ProtocoloverATM, MPOA) transmission, allows interconnection between different lanes, and supports the connectionless features and unicast, multicast, and broadcast transmission in the LAN. Each LANE customer LEC supporting LANE) is the LANE Protocol client, and the LANE Protocol server LE is responsible for running the LAN high-level protocol in the ATM network ).