DekTec DTC-720 Xpect - Manual (Page 9)

DTC-720 Xpect ® – 24/7 Transport Stream Monitoring
USER MANUAL
9
The runtime memory required by Xpect (M
RUNTIME
) must not exceed 75% of the total amount of memory
available. Xpect applies this restriction to ensure the system does not become unusable due to
resource starvation.
The memory usage estimate for HD AVC Mosaic service is less accurate compare to a SD service,
so make sure to have sufficient free Memory available.
2.3 Xpect server: required hard disk space
Like the memory usage, the required hard disk space depends on a number of variables such as the
number of transport streams, pre- and post-trigger buffer sizes and the maximum number of entries
to be stored in the log database.
The required disk space can be computed using the formulae below (all values in MB):
HD
CAP
= (B
PRE
+ B
POST
) x (212 ÷ 188) x N
FILES
, where:
HD
CAP
= Amount of disk space required for transport stream captures
B
PRE
= Size of pre-trigger buffer
B
POST
= Size of post-trigger buffer
N
FILES
= Number of transport streams capture files to store
HD
LOG
= N
LOG
× S
LOG
, where
HD
LOG
= Amount of disk space, per TS, required for the log database
N
LOG
= Maximum number of log entries to store
S
LOG
= Size of log entries in database (typically = 1kB)
HD
STAT
= (N
SHORT
+ N
MEDIUM
+ N
LONG
) × (N
SVC
+ N
BS
+ N
TBL
) × S
stat
, where
HD
STAT
= Amount of disk space, per TS, required for the statistics database
N
SHORT
= Maximum number of short-term statistics entries to store
N
MEDIUM
= Maximum number of medium-term statistics entries to store
N
LONG
= Maximum number of long-term statistics entries to store
N
SVC
= Number of services in transport stream
N
BS
= Number of basic streams in transport stream
N
TBL
= Number of tables in transport stream
S
LOG
= Average size of log entries in database (typically = 1kB)
HD
REQ
= N
TS
× (HD
CAP
+ HD
LOG
+ HD
STAT
), where
HD
REQ
= Total amount of required disk space
N
TS
= Number of transport streams monitored