User's Manual Part 2

Tech-X Flex
®
(NG2) Tech-X Flex User Guide - Firmware v06.50
6-51
Intro
Overview
Wi-Fi
Ethernet
System
IP/Video
MoCA
RF
Specs
6.11.2 Change Channel
NOTE: Video testing is a purchasable option. Please contact Spirent for more information.
The IPTV change channel test measures channel change time by measuring the time between IGMP
requests and resulting changes in the packet stream. The unit accomplishes this measurement by joining
a multicast stream and initiating an actual channel change, emulating the behavior of IPTV subscriber
STB equipment.
For more detailed information on the time calculation, see How channel change time is calculated on
page 6-52.
Setup - Change Channel
The Change Channel setup differs whether or not a channel guide is active. For more information on
channel guides, see About channel guides on page 6-53.
With an active channel guide:
The unit presents a table with which you can select the two channels for the test. All other required
information is prepopulated from the channel guide, such as IP addresses and port numbers. For more
information on how the channels are used, see How channel change time is calculated on page 6-52.
Figure 6-23 Change Channel setup - Page 1 (with channel guide)
NOTE: The screen has a small display area and can only show a limited number of channels from the
guide at once. Remember to use the scroll bars on the table and/or the arrow keys on the key
pad to locate the desired channels. Furthermore, be sure that the From Channel and To
Channel at the bottom accurately reflect the channels you want to test.
Preliminary issue - Limited distribution only!