IBM 3708 Description page 255

Using the Response Time Monitor
As networks become larger and more complex, many installations are having more
and more difficulty effectively managing them. When components within these
networks change due to installation of such functions as automatic switching from a
telephone line to a satellite link, a new routing table, or a new version of software in
one of the nodes, a display station operator may notice a significant improvement or
degradation in response time. When response time increases and a complaint is
registered with the network management desk at the host, the network manager has
no way of verifying the problem.
The objective of the 3708 Response Time Monitor (RTM) function is to provide a
means for the installation to manage the network by differentiating between a good
and a bad response time (as well as a response time that is questionable). The RTM
function accurately measures and records the transaction times of inbound host
attention (AID) operations from display stations that communicate with the host.
RTM information may
be
obtained by the control terminal operator and, if host
support is provided, by a network management application in the host.
This section provides information about the following subjects:
• The 3708 and host requirements
• Supported devices
• RTM and response time definitions
• RTM host interface
• Host request and 3708 response formats.
Host Requirements
No specific host support is required; however, RTM has a host interface for SNA
communication. Host programming support (NLDM Release
2)
is available for the
setting of RTM parameters from a host and for the collection and display of RTM
information at a NCCF operator station. The 3708 does not support RTM in
ASCII pass-through mode.
No host programming is required to use the 3708 Response Time Monitor function
for the display of response times. When NLDM is not used, the default values for
the 3708 RTM function parameters cannot be changed.
Supported Devices
The RTM function measures response times for keyboard displays operating in
protocol conversion mode (L U type
2).
Response Time Definitions
The 3708 allocates a series of five counters (Figure 8-1 on page 8-19) for each
configured device or logical terminal representing intervals of time into which the
various response times are mapped. Up to four counters may be set up by specifying
the maximum times, or boundaries, associated with each. If a response time is less
than or equal to a particular boundary, the counter associated with that boundary is
incremented at the end of the transaction. If not, the next boundary value is
checked. If the response time does not fit within any of the boundaries, then it is
mapped into the fifth, or overflow counter. Should anyone of the four boundaries
be specified as the maximum, the counter associated with that boundary becomes the
overflow counter and subsequent counters are ignored. By specifying boundary
8-18
IBM 3708
Description