S&T provides software for the analysis of OCAP Common Download carousels. Quite often there a number of external factors, essentially neither the set-top-box or TSBroadcaster, which can cause a code download to fail. Such factors include:
Overloaded or slow network connection betweem TSBroadcaster and the CMTS (for DSG delivery) or QAM modulalor (in-band).
Firewalls or switches that block multicast packets (DSG delivery).
UDP buffer size on the TSBroadcaster host Linux system.
Inadequate hardware platform for TSBroadcaster, possibly not enough RAM or a too slow CPU.
In addition, a poorly configured TSBroadcaster system can also result in download errors. For example:
Where there are multiple TSBroadcasters present, more than one system sending DSM-CC data carousels to the same multicast DSG application tunnel id.
Where there are multiple CVTs and DSG outputs defined, sending a CVT which references the incorrect application tunnel id.
Sending a CVT which references an incorrect co-signer CVC.
Inappropriate settings defined in the TSBroadcaster system.properties file, .e.g. setting output.oobdcSchedulingIntervalMs to a value which causes output to be too bursty for the receiver.
Selecting a carousel output bitrate which is too high for the set-top-box.
This software is designed to help detect the above and other causes of code download failure.
The CDL Monitor is provied by S&T as software only and should be installed on any suitable Linux system.
The analyser produces results which include:
A count of Application Tunnel, other UDP, non-UDP and non-IP packets.
The UDP traffic flow from the source IP to the multicast IP address and port.
Counts of PAT, PMT and DII PIDs.
Data on downloadId, txnid block size, version and modules count.
For each DII, the module information, including downloadId, a version, size (in bytes and blocks) and code image name.
For each module, the id, a first, last and interval.
Detection of UDP packets dropped from a module.
The CDL Monitor can accept a pre-captured PCAP file for input. Such files are generated either by Linux tcpdump(1) or WireShark.
Alternatively CDL Monitor will operate in a realtime mode and capture data from either unicast or multicast UDP at any point in the delivery chain prior to conversion of the carousel into RF.