Comtech EF Data CDD-562AL, Installation And Operation Manual

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CDD-562AL/564A/L Multi-Channel Demodulator Revision 0
IP Module Ethernet Interface MN-CDD562AL564AL
4–5
•
Additional statistics added to the compression statistics menu to give feedback on the
compression efficiency achieved.
4.2.3.1 ALDC vs LZS Compression Comparison
These numbers have been generated using an internally created test program. This program takes the
target benchmark files and splits the files into payload size chunks and compresses each chunk in a
separate invocation of the compression algorithm. This is important to note because most compression
algorithms are applied to the entire file data set as a single invocation of the compression algorithm,
which is easier for other types of compression algorithms (LZS, GZIP in specific). This, of course, does
not apply to streamed packet data across an IP network (e.g., FTP transfer).
Algorithm
Payload
size
File Set Ratio Algorithm
Payload
size
File Set Ratio
ALDC 1472 Calgary 1.76 LZS 1472 Calgary 1.66
ALDC 1000 Calgary 1.76 LZS 1000 Calgary 1.66
ALDC 500 Calgary 1.77 LZS 500 Calgary 1.68
ALDC 100 Calgary 2.09 LZS 100 Calgary 1.97
ALDC 1472 Canterbury 1.71 LZS 1472 Canterbury 1.61
ALDC 1000 Canterbury 1.72 LZS 1000 Canterbury 1.62
ALDC 500 Canterbury 1.74 LZS 500 Canterbury 1.63
ALDC 100 Canterbury 2.04 LZS 100 Canterbury 1.91