ACP 137

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ACP 137
chunk of the compressed data, whose size is less than or equal to the maximum segment size
allowed. In addition, the rule on segmentation at End of Line is relaxed (since compressed
files would typically not contain End of Lines and it is assumed that any implementation
which can support compressed file formats will not attempt to add additional characters into
the data stream). The file checksum is taken over the complete, data before compression, thus
ensuring that it has been uncompressed correctly. Where segmentation is also necessary,
individual segment checksums are calculated against the segment of compressed data, to
ensure that each is transmitted correctly.
PROCEDURES
REPLICATION POLICY
459. National agreements will be required to specify the frequency and type of replications
for each replicated area. There is no requirement that all replications from one nation to others
are necessarily at the same frequency or schedule.
460. Replication strategy and frequency should be dependent upon their data replication
requirements and capabilities. A recommended starting point is weekly for incremental and
monthly for verify replications. However, nations must allow for the possibility that
emergency replication requests may be required outside of the agreed schedule and at short
notice. Manual procedures (e.g. telephone call to the directory administration team) may also
need to be employed to inform the partner nation that an emergency transfer has been (or will
shortly) be sent.
BACKUP POLICIES
461. It is strongly recommended that directories are backed up before received data is
loaded into them, and that a test load is performed on an offline copy of the directory.
CONFIGURABLE OPTIONS
462. The following features should be configurable within a national implementation on a
bilateral basis with each other nation);
a. Frequencies for Incremental and Verify replications required per replicated area
(default = weekly for incremental and monthly for verify).
b. Maximum Data File Size (default = 2,000,000 bytes). This value indicates the
maximum files size which may be sent before segmentation should be employed.
This value and the next must be agreed between peer nations.
c. Maximum Segment Size (default = 1,500,000 bytes). This value indicates the
maximum segment size to be used. The value must be smaller or equal to the
Maximum Data File Size.
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