User data structured subfields

The user data structured subfields are in the BIND, but not at fixed locations. (These fields are not always at the same offset in the BIND because of the variable-length fields.) They must be in the correct order. VTAM® uses these architectural user data structured subfields during BIND processing as follows:

1. Unformatted user data

   Unformatted user data subfield X'00' is included, if provided by the user.

2. Mode name

   Mode name structured data subfield X'02' is included in all LU 6.2 BIND requests and responses sent by VTAM.

3. Session instance identifier

   All LU 6.2 BIND requests and responses sent by APPC VTAM carry the session instance identifier structured data subfield X'03'. The identifier is unique among sessions between two LUs.

4. Network-qualified network name

   Network-qualified PLU network name structured data subfield X'04' is included in all LU 6.2 BIND requests sent by VTAM.

   Network-qualified SLU network name structured data subfield X'05' is included in all LU 6.2 BIND responses sent by VTAM.

5. Random data

   Random data structured subfield X'11' is sent on BIND and BIND responses when the session is being established with session-level LU-LU session verification.

6. Security reply data

   Enciphered random data structured subfield X'12' is used on the BIND response when the session is being established with session-level LU-LU session verification.

7. Nonce data

   Nonce data is sent on the BIND in X'13' when password substitution support is indicated on the application-capabilities vector.

8. Security mechanisms

   Security policy information is sent on the BIND in X'14' when support for Generic Security Services (DCE security services) are requested on the application-capabilities vector.