SNT Service Levels Throughput

Throughput constraints and capabilities are of primary concern to the network analyst. As in mainframe capacity planning, the network analyst must consider the various workloads that affect the data center. Workload can conveniently be divided into two broad classes:
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Throughput constraints and capabilities are of primary concern to the network analyst. As in mainframe capacity planning, the network analyst must consider the various workloads that affect the data center. Workload can conveniently be divided into two broad classes:

Logical Workloads

Logical workloads are directly related to the end user. Planning for new systems or major configuration changes is usually concerned initially with logical workloads. Logical workloads can be subdivided into two categories: application workloads and organization (business) unit workloads.
Application workloads are identified in the following files:
  • SNTPSY - NPM System Activity File
  • NVSLSY - NLDM System Activity File
  • SNTNSP -
    NetSpy
    Application File
Organizational unit workloads can be identified via the use of account code data elements in the following files:
  • SNTNAC - NCP Network Accounting File
  • SNTNSS -
    NetSpy
    Terminal File
  • SNTPSU - NPM User Activity File
  • NVSNSA - NLDM Session Accounting File
  • NVSNSC - NLDM Session Connectivity File
  • NVSRTM  -NLDM Response Time File
  • NVSRTE - NLDM Route File
Sample account code definition members are included with this product, and the use of account codes is discussed in the Complex-level Parameters section. However, it is your responsibility to verify that the account code structure meets the requirements of your data center, and, if not, to make any necessary modifications. In this way, you are assured the greatest flexibility in defining an account code structure that will satisfy your network analysis and reporting requirements.

Physical Workloads

Physical workloads are directly related to network topology and may only incidentally be related to the end user. Localized network performance considerations such as load balancing and NCP parameter selection are most often concerned with physical workloads. Physical workloads can be divided into two categories: boundary workloads and backbone workloads.
The sequence/summary variable SLULINK in the NPM Link Activity (SNTNPL) File and the NLDM Link Activity (NVSNLL) File contains the name of the peripheral link to which the secondary logical unit's physical unit is attached. Network boundary (peripheral link) workloads may thus be identified directly. Coincidentally, they may also be identified in the
NetSpy
Terminal (SNTNSS) File, and in the NLDM Service (SNTNSV) and the NLDM System Activity (NVSLSY) Files, depending on the definition of performance classes for NetView/NLDM and RTM classes for
NetMaster
NTS.
Performance problems related to boundary workloads are limited in scope because they are localized to a specific peripheral link. However, if the link attaches a distributed processor, a significant number of end users may be affected.
Backbone workloads may be identified by summarizing utilization data to the level of the primary and secondary logical unit's subareas (note that the
MICS
summarization facility, explained in Standard Reporting, should always be utilized for any summarization of
MICS
files). This yields the traffic load between subarea "x" and subarea "y".
If you are processing
NetSpy
Virtual Route Activity data, you will find information about both SNA backbone virtual route traffic volumes and response times in the
NetSpy
Virtual Route Activity (SNTNVR) File.
Performance problems that are related to backbone workload constraints can have far-reaching effects in the network and should be closely tracked. Relatively small changes in the traffic mix (message lengths, chaining characteristics, etc.) can cause significant increases in the utilization level of the backbone communications control units.
The following sections suggest key data elements, exception conditions, reports, and sample analysis that may be helpful in the management of network throughput levels: