Configuration Parameters › Destination Parameters for Single LUs, Groups of LUs, and Single IPNAMEs › COMPRESS

COMPRESS

This parameter specifies whether data compression is used for a transfer.

YES

CA XCOM Data Transport provides Run Length Encoding (RLE) only for blanks and binary zeroes.

NO

No data compression takes place.

RLE

CA XCOM Data Transport provides complete RLE for all repeating characters.

COMPACT

CA XCOM Data Transport provides complete RLE (as in RLE) plus a byte compaction scheme suitable for uppercase EBCDIC text.

COMPACTL

The COMPACTL compression parameter is the same as COMPACT. However, this value is most suitable for lowercase EBCDIC text.

LZSMALL

CA XCOM Data Transport compresses the data according to the small memory model of Lempel‑Ziv 77 compression.

LZMEDIUM

CA XCOM Data Transport compresses the data according to the medium memory model of Lempel‑Ziv 77 compression.

LZLARGE

CA XCOM Data Transport compresses the data according to the large memory model of Lempel‑Ziv 77 compression.

HUFFMAN

Greater compression than RLE but not as much as the Lempel-Ziv 77 modes.

LZRW3

A general-purpose algorithm that runs fast and gives a reasonable compression.

ZLIB(n)

Greater compression than LZRW3 but less than LZSMALL, LZMEDIUM, and LZLARGE. The n value can be 1 through 9.

Default: YES

Notes:

• Specifying a value other than NO enables use of zIIP to perform the compression function. zIIP processing is used for compression only if the buffer size to compress is >= 4096 bytes. Specifying PACK=LENGTH and use a high MAXPACK value (>= 4096) for TCP/IP transfers or RUSIZE (>=4096) for SNA transfers to use zIIP.
• The compression method that is specified for the COMPRESS parameter must be a permitted algorithm (using the COMPRESS_ALLOWED server configuration parameter). If the specified compression method is not permitted in the server, the DEST member activation fails.