Testing PPPoX and L2TP Broadband Access Devices - Ixia

• Simulate an access link failure for each of the above test
cases. Note the number of session retries and session
recovery times.
• Simulate a system failure for each of the above test
cases.
Note the number of session retries and session recovery
times.
2. PPPoX Client and Server
Performance and Scalability Test
2.1 Objective
The objective of this test is to characterize the performance
of both LAC and LNS/B-RAS devices when forwarding
32,000 PPPoX sessions including both control and data
plane traffic. The test is split into two phases, namely:
• Control plane traffic generation (PPPoE, PPPoA,
PPPoEoA, PPPoEoVLAN).
• Data plane traffic generation (IMIX and fixed frame sizes
at 100% utilization).
2.2 Setup
When emulating both client and server, the test tool creates
the requested number of subscribers (i.e. 32,000 in this
case) as well as terminates the incoming PPP sessions,
thus bracketing the DUT. The DUT may consist of single or
multiple devices (e.g. DSLAM).
As shown in Figure 7, 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 PPP
sessions. In addition, these ports generate the data plane
IP traffic.
2.3 Input Parameters
The primary input parameters for each phase include:
• Session setup rate & latency – maximum, minimum and
average time and latency to establish all sessions with
either no authentication, PAP or CHAP authentication.
• Interfaces, VLANs and domain groups for access and
network ports.
• Traffic generation – upstream/downstream/bi-directional
for stateless L3/L4 traffic (IMIX or fixed frame
distributions).
• Session teardown rate.
2.4 Test Methodology and
Result Generation
• Session setup test:
− Test tool to generate 32,000 PPPoX sessions.
− Record setup rates and latency measurements
outlined in section 1.2.
− Record the number of sessions in the DUT.
• Traffic generation over PPPoX test:
− Test tool to generate L2/3 stateless traffic. For
example, 20% upstream and 80% downstream
IMIX traffic (64, 128, 512, 1024 and 1518 byte
frames over TCP). See Figure 3 in Section 1 for
setup details.
• Session tear down test:
− Test tool to tear down sessions at a fixed rate
(e.g. 100 sessions per second).
Access Side
- PPPoE, PPPoEo802.1q
- PPPoEoA, PPPoA
DUT
Access Concentrator
Network Side
- PPPoE, PPPoEo802.1q
- PPPoEoA, PPPoA
10/100/1000 Ethernet
Or OC3/OC12 ATM
10/100/1000 Ethernet
Or OC3/OC12 ATM
Figure 7: PPPoX client and server emulation setup
PoE Test Plan Copyright © Ixia, 2004 7