5. DATABASE FILES › 5.2 SNT Information Area › 5.2.1 NCP Link File (SNTNCL) › 5.2.1.3 Usage Considerations

5.2.1.3 Usage Considerations

This section identifies the special considerations or
techniques related to using the SNTNCL file, followed by
several retrieval examples.


In the examples, a SAS macro variable is used to specify the
DDname part of the CA MICS file name. These macro variables
are a standard part of CA MICS and are available for all
files. The macro variable name has the form &diiit, where d
is the database identifier, iii is the information area
name, and t is the timespan.  For the examples, a database
identifier of P is used.  The identifier is installation
dependent, so you should find out what the identifiers are at
your installation.

Special Considerations/Techniques

1. Exercise care in using the special date and time data
   elements contained in each CA MICS file. As the file's
   granularity increases in higher timespans, certain fields
   lose significance and should not be used in those cases.

   o HOUR should not be used in MONTHS.
   o DAY and DAYNAME should not be used in WEEKS or MONTHS.
   o WEEK should not be used in MONTHS.

2. The following data elements are user-defined.  The value
   in each depends on user-selected options or user-supplied
   SAS code:

   o NETWRKID - Network Identifier.  A one to eight-character
     descriptive name for each network represented in the
     data.  NETWRKID is set in the Network Identifier Exit
     Routine, SNTNIDRT, discussed in Chapter 7.  For NPM,
     NETWRKID may be set to the value of PLU Network
     Identifier (PLUNETID).

   o LNKTPCID - Link TP Circuit ID value.  This data element
     will typically contain the value of the link vendor's
     (AT&T, MCI, etc.)  billing identifier.  It is set in the
     Link TP Circuit ID Exit Routine, SNTCIDRT, discussed in
     Chapter 7.

   o TMOFFSET - Time offset applied to the data in the file.
     The user can associate a time offset with each unique
     NETWRKID/SYSID combination.  This offset is used to
     adjust data times when data from multiple time zones is
     brought together in the CA MICS database. To determine
     the original time at which the data was recorded,
     subtract TMOFFSET from the value.  Time offset is
     assigned in the SNTOPS member of prefix.MICS.PARMS,
     discussed in Chapter 7.

3. The following data elements lose significance once
   summarization has been performed.  You should reference
   these data elements only when the last observed value in a
   summarization interval is significant.

   LINKSPD  - Link Speed
   NPMTSFRU - Forward RU Send Time
   NPMTSLOG - Time Record Logged to SMF
   NPMTSEIS - Expected Interval Time
   NCLNRRLS - Receiving Link Speed
   NCLNRSLS - Sending Link Speed

4. If the data source for this file is the CA NetSpy SMF
   Record, then the following element will have missing
   values:

   o NPMTSFRU - Forward RU Send Time

5. The CA MICS Network Analyzer Option makes the following
   assumptions and calculations regarding link speed data
   elements:

   o The values coded for sending and receiving line speeds
     in NCP generations are generally for documentation
     purposes only; however, the majority of data centers
     code a value for sending line speed.  The typical
     exception to this "rule" is for full duplex lines, where
     NCP parameters for both sending and receiving line
     speeds may be appropriate.

     Note:  Line speeds are required for those devices (for
     example, modems) that use external clocking.

   o LINKSPD -  In the case of full duplex lines where both
     sending and receiving line speeds may be coded,
     LINKSPD will be the maximum of both line speeds.  For
     half duplex lines, it will be the primary line speed.

   o NCLPCELB (Percent Link Busy Retransmission) - sending
     line speed used if greater than zero, else set to
     missing.

   o NCLPCLBS (Percent Link Busy) - LINKSPD used if greater
     than zero, else set to missing.

   o NCLPCRLB (Percent Link Busy Receiving) - receiving line
     speed used if coded in NCP gen; if receiving speed is
     zero, sending speed is used if it is greater than zero
     (else set to missing).

   o NCLPCSLB (Percent Link Busy Sending) - sending line
     speed used if greater than zero, else set to missing.

6. The values of the following elements include retransmitted
   bytes:

   o NCLPCLBS (Percent Link Busy)
   o NCLPCRLB (Percent Link Busy Receiving)
   o NCLPCSLB (Percent  Link  Busy  Sending)
   o NCLNRCHR (Number of Bytes Received)
   o NCLNRCHS (Number of Bytes Sent)
   o NCLNRIFR (Number of I-Frames Received)
   o NCLNRIFS (Number of I-Frames Sent)

   That the above elements include retransmitted bytes is a
   feature of how the NCP NPA logical unit measures bytes
   sent and received, not a feature of CA MICS.

   That the above elements include retransmitted bytes is an
   important consideration, if, for example, you are creating
   a stacked vertical bar chart of Percent Link Busy and
   Percent Link Busy Retransmission.  Unless you subtract the
   latter measurement from the former one, the resulting
   total percentage may be greater than 100.

Retrieval Examples

1. To produce a chart depicting the percent of line busy
   during the peak hour for the last five days:

   DATA SELFILE;
     SET &PSNTD..SNTNCL01 &PSNTD..SNTNCL02 &PSNTD..SNTNCL03
         &PSNTD..SNTNCL04 &PSNTD..SNTNCL05;
     IF HOUR=14 AND NETNAME='LN001003';

   PROC CHART DATA=SELFILE;
     VBAR DAYNAME / SUMVAR=NCLPCLBS;

2. To produce a report depicting the 25 lines having the
   highest count of retransmitted bytes yesterday:

   %LET BY = NETWRKID SYSID NETNAME ;
   %LET BREAK = NETNAME ;

   PROC SORT DATA=&PSNTD..SNTNCL01 OUT=WKNCL;
     BY &BY;

   DATA WKNCL;
     SET WKNCL;
     %NCLSUM;

   PROC SORT DATA=WKNCL;
     BY DESCENDING NCLNRRBY;

   OPTIONS OBS=25;
   PROC PRINT DATA=WKNCL;
     ID NETNAME;
     VAR SYSID NCLNRRBY;