Testing PPPoX and L2TP Broadband Access Devices - Ixia

Overview
Modern broadband networks deployed to provision xDSL
or cable-based high-speed Internet access services to
residential and commercial users rely on a number of
complex devices to offer a high quality experience to the
user. Prior to network deployment, these devices are
commonly tested for:
• Performance, e.g. can the device handle a specified
number of session setup requests per second
• Scalability, e.g. does the device meet its maximum
session specifications
• Functionality, e.g. do the advanced firmware features in
the device interoperate with other parts of the network
while maintaining scalability
This document provides test case examples covering these
requirements for three main device classes, namely:
• Broadband Remote Access Servers (BRAS)
• Layer 2 Access Servers
• Layer 2 Network Servers
Four iterative test case examples are being presented.
• PPPoX client performance and scalability test
• PPPoX client and server performance and scalability test
• L2TP LAC performance and scalability tests with
PPPoX traffic
• L2TP LNS performance and
scalability tests
PPPoX includes a number of
technologies such as PPPoE,
PPPoA, PPPoEoA, PPPoEoVLAN.
The PPPoX version tested depends
on the interface options available in
the Device under Test (DUT)/
System under Test (SUT) and the
corresponding Ixia Load Module.
While the total number of PPPoX
sessions needed to perform stress
tests depends on capabilities of the
DUT, this document assumes that
the test tool is capable of generating
32,000 sessions per test.
1. PPPoX Client Performance
and Scalability Test
1.1 Objective
The objective of this test is to characterize the performance
of both LAC and LNS/B-RAS devices while simulating
32,000 PPPoX sessions. The test is split into three phases,
namely:
• Baseline session setup and teardown tests.
• Simulating access link failure test. This can be achieved
by simply disconnecting and reconnecting the link
from the test tool to the DUT to observer service
recovery times.
• Simulate DUT failure test. This can be achieved by
re-booting the DUT.
1.2 Setup
The DUT may consist of single or multiple devices (i.e.
Access concentrator/LAC and LNS or LNS or BRAS, etc.).
As shown in Figure 1, an Ixia GigE Load Module port
(copper or fiber) or ATM Load Module port (OC3 or
OC12) may be used to generate the required number
of subscribers (access users) for one or more PPPoX
sessions.
Figure 1: PPPoX client emulation setup
PoE Test Plan Copyright © Ixia, 2004 1