Find Test Solutions for IPTV
| Residential service turn-up and troubleshooting |
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Core/metro network testing |
More on Residential IPTV Service Testing
Here is a five-step approach for IPTV service installation and
troubleshooting:
- Step 1: Check the rates of the ADSL/ADSL2+ link.
- Step 2: Ensure that DSL rates are stable.
- Step 3: Be sure that ATM errors are consistently low.
- Step 4: Test IP and MPEG video layers.
- Step 5: Confirm the video quality for at least 15
minutes.
To perform these steps, field technicians need an advanced modular
test set (such as the CoLT-450P) that will provide all the
required information for the installation, maintenance and/or
troubleshooting of ADSL circuits carrying IPTV and VoIP services.
Multiple video-coding standards are supported, including MPEG-2, MPEG-4
and WM9/VC-1.
Analysis performed by the IPTV tester include:
- ADSL connection and bit rate
- Network status
- Stream analysis
- IGMP packet statistics
- IPTV service errors
- Jitter levels
- QoS summary
Figure 1. Ethernet 10/100 Through mode.
Figure 2. Ethernet 10/100 Terminate Mode.
Figure 3. IPTV service analysis in Through mode: The AXS-200/625 bridges the DSL and Ethernet networks, while the STB is used as the end-point device.
Figure 4. IPTV service analysis in Terminate mode: The AXS-200/625 performs stand-alone indoor and outdoor testing (this is a typical test setup with a unit at the NID).
More on Core/Metro Network IPTV Testing
Powerful portable testing tools can measure the quality of the video traffic over the network. The portability of the solution allows technicians to quickly deploy at different points in the network to collect data and help isolate a network fault affecting the quality of the IPTV service.
Figure 5. Single-port IPTV test
The FTB-8510B Ethernet Test Module`s IPTV option, combined with the FTB-400 Universal Test System platform, is a prime example of such a solution, delivering high-performance measurement capabilities and over 35 different IPTV metrics and statistics. The key features provided with the IPTV software option include media delivery index (MDI), RFC 4445, TR 101 290 Priority 1 metrics in addition to program clock reference jitter, stream rate and bandwidth utilization on 100 simultaneous MPEG-2 or MPEG-4 streams.
Where to Measure
IPTV testing can be performed at multiple points in the network, where an electrical or optical Ethernet interface supporting rates from 10 Mbits/s to 1 Gbits/s is available; testing is typically conducted through a test port where the test set cannot affect the live traffic.
Figure 6. IPTV network testing locations
There are three points in the network that are critical to monitor for IPTV quality: national head-end, regional head-end and at the closest point to the customer (typically the input to the DSLAM). For a more detailed and consolidated view of the network status, IPTV streams should be monitored at every major routing point in the network. The more sample points you have in the network, the easier it will be to isolate network faults when they occur.
When to Measure
The IPTV network must also be tested upon introduction of new services, so as to characterize the network. In addition, it should be monitored constantly to limit unexpected service degradation. Figure 6 presents a typical test configuration where the FTB-8510B can be used to monitor a specific section of the IPTV network using a single-port test topology. Test connections can be established to monitor the IPTV streams at appropriate test points available from the core or access network devices (video streamers, routers, switches, etc.).
What to Measure
Test sets like the FTB-8510B module provide the capability to simultaneously monitor up to 10 unicast or multicast IP addresses to support IPTV monitoring (including basic VoD monitoring). The monitoring function includes the ability to report statistics on MDI and PCR jitter in addition to other key statistics such as IP packet metrics, stream rate and presence measurements, as well as bandwidth utilization, all of which are essential to correctly characterize an IPTV stream.
The support of MDI metrics makes the FTB-8510B a very useful tool for detecting and isolating network faults that are directly linked to video quality of service and ultimately the end users QoE. MDI measurements made through the video stream path can be used to help isolate error points in the network. For example, if there is a large increase in DF between two successive points, it may be an indication of congestion at a routing point that is causing excessive delay. This can also potentially cause packets to be dropped; therefore, the MLR metric will increase as well. Similarly, a spike in MLR values can indicate that a router is corrupting MPEG TS packets or receiving out-of-sequence packets due to latencies in the network.
MDI measurement guidelines that correspond to an acceptable QoE is highly dependent on the network architecture and on the amount of buffering in the set-top box. Typically, set-top box manufacturers try to limit the amount of buffering capability in order to reduce the cost of the unit.