Configuring L2TP Services

No active call from mmark; no tunnel needed

mmark@baynetworks.com

PC

 

No L2TP

Modem

functionality

 

jsmart@baynetworks.com

PC

 

 

 

TA

Multilink

 

 

No L2TP

ISDN

PPP

functionality

 

 

 

ISP network

 

 

 

 

LAC 2

 

 

 

 

TMS

 

 

 

 

 

 

 

Corporate

 

 

 

network

 

 

 

 

Router

LAC 1

Frame relay

LNS

 

 

192.32.16.55

 

 

.26.0

 

 

 

 

 

.17

 

Tunnel

 

 

 

 

 

 

 

 

192.32.68.2

RADIUS server

 

 

L2TP IP

 

 

 

 

192.32.26.6

 

 

interface

 

 

 

 

 

bay_private

Domain name in TMS database baynetworks.com = 192.32.16.55

IP addresses in the

RADIUS server database

192.32.40.1 jsmart@baynetworks.com 192.32.40.2 mmark@baynetworks.com

L2T0007B

Figure B-1. L2TP Network with PCs at the Remote Site

Configuring the Remote Hosts

The remote hosts in this network are two PCs running Windows 95. Neither PC has internal L2TP capabilities.

In this network, one PC has a synchronous dial connection to the ISP via a modem. The other PC has a 128 Kb/s dial ISDN connection through an ISDN terminal adapter (TA).

The user names at the PCs are mmark@baynetworks.com and jsmart@baynetworks.com.

B-2

303532-A Rev 00

Page 72
Image 72
Nortel Networks manual Configuring the Remote Hosts, Figure B-1. L2TP Network with PCs at the Remote Site

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.