1, 1483b: That is to refer to the 1483 bridge protocol, which is generally mentioned, based on the basic bridge protocol, which is implemented on the first layer (physical layer) of the network, and modem just acts as a bridge when using the scheme. The device, does not provide any protocol conversion or address filtering, usually after the MODEM can be synchronized with the DSLAM, after the VPI / VCI is set, it is basically able to access the Internet, in short, MODEM only acts as HUB Function, there are several networked schemes in this scheme, which can implement a dedicated online network (ISP assigns fixed IP addresses and subnet masks and default gateways, where the NAT function is not supported, the address information must be configured. On the user's PC), the PPPoE dial mode can also be implemented (Modem uses 1483B mode, installing a third-party dialing software on the user PC); however, now many places also use the 1483b NAT, 1483B DHCPClient function (this feature is For the way, MODEM's WAN port can dynamically obtain the IP address, which can reduce the management of ISP). 2, 1483R: Refers to the 1483 routing mode, which can implement routing function on the bridge basis. When this mode, the public IP address can be set in the MODEM's wide area network port, and the private IP address is set in the MODEM LAN port. Address conversion function easily. 3, 1577: IPOA, transmit IP packets through the ATM network, in which user must have a fixed IP address and subnet mask and other network parameters, because the username and password verification cannot be provided in this mode, cannot be Meeting QoS services such as network management and security during network usage, this method is basically no longer widely used; 4, 2364: PPPOA, this mode is basically the same as the RFC1577 above, but it is based on ATM and ISP After the physical connection, the PPP protocol establishes a session on the link layer and the network layer. When using this protocol mode, security verification functions such as PAP, CHAP can be implemented, so that the security management of the ISP network provides corresponding support. In this mode, the address of the Modem is automatically assigned by the ISP's DHCP server after establishing a connection via the PPP protocol. 5, 2516: PPPoE, this method is based on bridge mode. When using this mode, when the MODEM is established by the MODEM and DSLAM, the user ends (when using the PPPoE mode on the MODEM, the user end refers to modem) PPP request, through PAP (PAP: Password authentication protocol, is a form of user identity authentication, which verifies the legality of the user through user name and user password, because the user's ID and password are directly transmitted on the link on the link, Thus, the security is poor) or the CHAP (chap: chasing the handshake certification protocol, is also a form of user authentication, it issues an authentication question by the server, the user verifies the legality of the user in the form of a response, because the user's ID and password pass After encryption, the network is transmitted on the network, so its security is better) Two verification methods through UAS authentication in the ISP, and establish a network connection.
