Understanding the Session Awareness Interface › NTS-SI Configuration

NTS-SI Configuration

NTS-SI lets SAW data and session data collected in one domain be passed on to another NTS running in another domain, provided that a direct ISR link exists.

Transfer of Session Data Using an ISR Link

Suppose that session B1-B2 exists between two resources, B1 and B2, in domain B. For the NTS in domain A to be aware of SAW and session data for this session, the following conditions must be true:

• NTS must be active in both domains.
• An ISR link must exist between the domains. The link must be configured so that NTS A is specified as the receiving region (that is, the SAW operand of the ISR command is set to INBOUND) and NTS B is specified as the sending region (that is, the SAW operand of the ISR command is set to OUTBOUND).
• Class definitions in NTS B must specify that data associated with session B1-B2 is to be forwarded.
• Class definitions in NTS A must specify that data associated with session B1-B2 is to be retained.

Provided that these conditions are met, a session start notification received by NTS B from VTAM B is forwarded across the ISR link to NTS A. If any session data arrives for session B1-B2 from VTAM B, NTS B forwards an indication to NTS A that this data is available. Users of NTS A can solicit this data, as required, from NTS B. When the session ends, a session end notification received by NTS B from VTAM B is forwarded to NTS A. NTS A performs end-of-session processing for this session according to the session class definition.

The following illustration shows this process.

Note the following in this illustration:

• VTAM in domain B supplies NTS B with data relating to teh session between resources B1 and B2, which in turn is forwarded to NTS A.
• Arrows indicate the flow of data.

Data Propagation Across ISR Links

In a cross-domain environment (single network), NTS forwards data it has received from the local VTAM to other NTS regions. SAW and session data received using ISR from a remote VTAM are not forwarded, shown in the following illustration.

In this illustration, NTS B has information for sessions in domains A and B. NTS B forwards data relating to sessions in domain B to NTS C, but does not forward data relating to sessions in domain A. Therefore, when constructing a network image, NTS C cannot include SAW and session data from domain A.

Note the following in this illustration:

• The NTS in doman C does not include data from domain A in its single image because there is no direct link from A to C.
• Arrows indicate the flow of data.

Star Network Configuration

For single network image presentation, the most useful configuration of NTS regions is a star network, which enables the monitoring of network activity to be centralized (or distributed). The following illustration shows an optimum NTS-SI configuration for a five-domain network (arrows indicate the flow of data).

The central (hub) NTS region monitors all network activity in its own domain and in the outlying (spoke) domains; the spoke NTS regions monitor the activity in their own domains only. This configuration parallels the Communication Management Configuration (CMC), where a hub domain owns all the devices and the applications reside in the spoke domains.