Accepting remote attachment requests
When VTAM® has established a conversation for a remote application, that application sends a remote request, which is a request to attach to your local DB2® subsystem.
About this task
Make sure that you do not confuse the remote request with a local attachment request that comes through one of the DB2 attachment facilities—IMS™, CICS®, TSO, and so on. A remote attachment request is defined by Systems Network Architecture and LU 6.2 protocols; specifically, it is an SNA Function Management Header 5.
In order to accept remote attachment requests, you must first define your DB2 to VTAM with the conversation-level security set to "already verified". That is, you need to code SECACPT=ALREADYV on the VTAM APPL statement. The SECACPT=ALREADYV setting provides more options than does SECACPT=CONV or "conversation", which is not recommended.
The primary tools for controlling remote attachment requests are entries in tables SYSIBM.LUNAMES and SYSIBM.USERNAMES in the communications database. You need a row in SYSIBM.LUNAMES for each system that sends attachment requests, a dummy row that allows any system to send attachment requests, or both. You might need rows in SYSIBM.USERNAMES to permit requests from specific IDs or specific LUNAMES, or to provide translations for permitted IDs.