Virtual Private Networks (VPNs)
modes: Transport and Tunnel. Transport mode encrypts only the data portion (payload) of each packet, but leaves the header untouched. The more secure Tunnel mode encrypts both the header and the payload. On the receiving side, an
DES stands for Data Encryption Standard, a popular
•Ascend Tunnel Management Protocol (ATMP) is the protocol that is implemented in many Ascend gateways. ATMP is a simple protocol for connecting nodes and/or networks together over the Internet via a tunnel. ATMP encapsulates IP or other user data without PPP headers within General Routing Encapsulation (GRE) protocol over IP. ATMP is more efficient than PPTP for
When used to initiate the tunnelled connection, the Router is called a PPTP Access Concentrator (PAC, in PPTP language), or a foreign agent (in ATMP language). When used to answer the tunnelled connection, the Motorola Netopia® Router is called a PPTP Network Server (PNS, in PPTP language) or a home agent (in ATMP language).
In either case, the Motorola Netopia® Router wraps, or encapsulates, information that one end of the tunnel exchanges with the other, in a wrapper called General Routing Encapsulation (GRE), at one end of the tunnel, and unwraps, or decapsulates, it at the other end.
Configuring the Motorola Netopia® Router for use with the different protocols is done through the
•"About PPTP Tunnels" on page
•"About IPsec Tunnels" on page
•"About L2TP Tunnels" on page
•"About GRE Tunnels" on page
•"About ATMP Tunnels" on page
Your configuration depends on which protocol you (and the gateway at the other end of your tunnel) will use, and whether or not you will be using VPN client software in a standalone remote connection.
Note: You must choose which protocol you will be using, since you cannot both export PPTP and use ATMP, or vice versa, at the same time.
Having both an ATMP tunnel and a PPTP export is not possible because functions require GRE and the Router’s PPTP export/server does not distinguish the GRE packets it forwards. Since it processes all of them, ATMP tunneling is impaired. For example, you cannot run an ATMP tunnel between two gateways and also have PPTP exported on one side.
Summary
A Virtual Private Network (VPN) connects the components of one network over another network. VPNs accomplish this by allowing you to tunnel through the Internet or another public network in a manner that provides the same security and features formerly available only in private networks.
VPNs allow networks to communicate across an IP network. Your local networks (connected to the Motorola Netopia® Router) can exchange data with remote networks that are also connected to a
