L2TP Overview

Bay Networks L2TP Implementation

In an L2TP network, the Bay Networks router is the LNS. LNS software operates on the BLN® , BCN® , and ASN™ platforms.

The Bay Networks LNS has the following characteristics:

•Each slot can act as an LNS, which means that one router can have many LNS interfaces, each with its own address. You can have as many LNS interfaces as there are available slots on the router.

•The LNS performs user authentication with a RADIUS server to prevent unauthorized users from accessing the network.

•The LNS accepts only incoming calls; it does not place calls to the LAC.

•The Bay Networks L2TP implementation supports only IP traffic through the L2TP tunnel. The LNS supports only numbered IP addresses.

•The router interface between the ISP and the corporate network (see

Figure 1-1 on page 1-7) is a leased line operating with frame relay, PPP (including PPP multilink), or ATM. Bay Networks recommends that you use a high-speed link, such as T1, for the leased connection.

•The LNS terminates PPP multilink and PPP encapsulated data within an L2TP packet.

•The LNS operates with the LAC implementation configured on the Bay Networks Model 5399 Remote Access Concentrator.

•The host (PC or router) dialing into the ISP network can be on the same subnet as the IP interface on the LNS.

•The LNS supports RIP. RIP is particularly useful when the remote host is a router, because it enables the LNS to learn routing information from the remote router.

For instructions on how to configure a Bay Networks router as an LNS, see Chapter 2, “ Starting L2TP.”

303532-A Rev 00

1-11

Page 26 Page 28
Page 27
Image 27
Nortel Networks manual Bay Networks L2TP Implementation
Page 26 Page 28

L2TP specifications

Nortel Networks L2TP, or Layer 2 Tunneling Protocol, is a widely recognized networking protocol that enables the tunneling of data over various networks. Initially developed as an extension of the Point-to-Point Tunneling Protocol (PPTP), L2TP integrates components from both PPTP and Layer 2 Forwarding (L2F). Nortel Networks played a significant role in the development and implementation of L2TP, making it a prominent choice for service providers and enterprise networks seeking secure and efficient connectivity.

One of the primary features of L2TP is its ability to encapsulate data packets, allowing the transport of PPP (Point-to-Point Protocol) frames without necessitating the traditional point-to-point connections. This means L2TP can operate across different networks, facilitating remote access connections and VPNs (Virtual Private Networks). As a result, organizations can achieve greater flexibility in managing their communications infrastructure.

Another key characteristic of L2TP is its support for both IPv4 and IPv6, ensuring compatibility with current and future networking environments. L2TP operates at the link layer of the OSI model, which means it functions between the data link and network layers, making it versatile for various applications. By using UDP (User Datagram Protocol) as a transport protocol, L2TP ensures efficient data transmission while maintaining lower latencies.

Security is a critical aspect of L2TP. While L2TP itself does not provide encryption, it is often paired with IPSec (Internet Protocol Security) for enhanced security protocols. This combination offers both tunneling and encryption, creating a secure framework for transmitting sensitive information across potentially insecure networks, such as the Internet.

L2TP also features various authentication methods, allowing for robust access control. It supports various schemes like PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol), giving network administrators a range of options to ensure the legitimacy of users accessing the network.

In summary, Nortel Networks L2TP is a powerful tunneling protocol known for its flexibility, compatibility, and security features. Its ability to encapsulate data for efficient transport makes it ideal for remote access and VPN applications. As organizations continue to demand secure, seamless connectivity, L2TP remains a resilient choice within the shifting landscape of networking technologies.
Top Page Image Contents