SNAX/APC Configuration and Management Manual

Planning for SNAX/APC

SNAX/APC Configuration and Management Manual—138787

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Conversation-Level Security Considerations

The conversation-level security provided by SNAX/APC is best understood when

viewed within the larger context of APPC security. The following discussion of APPC

security is intended to provide that context.

APPC Security

The APPC architecture describes two levels of security, session-level security and

conversation-level security. A brief description of each level follows.

Session-Level Security

The APPC architecture describes two types of session level security, encryption and

LU-LU verification. Encryption enables the transmission of application data in an

encrypted form. LU-LU verification is a challenge-response protocol that enables two

Notes.

1. The VTAM APPL (application definition) statement defines CICS to VTAM. The name field

(CICS1) of the APPL statement is the uninterpreted VTAM LU name. It is unique within

the domain. The ACBNAME (CICS) parameter is the network name. It is unique within

the SNA network. This name combination allows users to log on to CICS and be

connected to the copy of CICS in their domain, such as either CICS1 or CICS2.

2. AUTH=(VPACE) indicates that CICS supports VPACING; (NVPACE) indicates that it does

not. You should specify VPACE here for CICS to prevent overloading buffers in VTAM and

NCP.

3. VPACING controls the pacing on all LUs associated with the application. Usually this

parameter is not used, because different LUs have different pacing requirements.

4. Parameters can be specified on the PU macro, on the LU macro, or on both. If a value is

specified on both, the LU value overrides the PU specification.

5. The MODETAB parameter names a logon mode table to search for the mode entry for this

LU.

If the mode name is not found in this table, or if this parameter is not specified, an IBM-

supplied mode table is used. You cannot modify or replace the IBM-supplied mode table.

6. DLOGMOD names a default logon mode table entry for this LU. CICS overrides this

parameter.

7. The pacing counts specified in the LU definition apply to all sessions with the LU. These

counts can be overridden by the nonzero counts in the logon mode table entry. Finally, the

PLU application can change the primary receive count. The count must be zero for the

current release of SNAX/APC.