Transmission services profile
The transmission services profile identifies a predefined set of
session-control requests that can be used in a session. Each profile
represents a different set of session-control requests and other transmission
services attributes. For a detailed description of the transmission
services profiles, see SNA Formats The following profiles
are available to the VTAM® application
program and can be specified in the transmission services field (using
the TSPROF operand of the MODEENT macroinstruction).
- Bit setting 0123 4567
- (Byte 2) Meaning
0000 0010- Transmission services profile 2 is to be used. (This profile applies only to LU type 0 3270 sessions.)
0000 0011- Transmission services profile 3 is to be used.
0000 0100- Transmission services profile 4 is to be used.
0000 0111- Transmission services profile 7 is to be used.
The session-control requests that apply to each of these profiles are shown in Table 1.
In this table:
- Req
- This request must be used. The required requests can be issued by VTAM on behalf of the application program.
- Opt
- This request can be used.
- N/A
- Not applicable. This request must not be used.
| Session- control request | Profile 2 | Profile 3 | Profile 4 | Profile 7 |
|---|---|---|---|---|
| CLEAR | Opt | Opt | Opt | N/A |
| RQR | N/A | N/A | Opt | N/A |
| SDT | N/A | Req | Req | N/A |
| STSN | N/A | N/A | Opt | N/A |
The function management usage field
is used to supplement the protocol rules defined by the function management
profile. The function management usage field is divided into three
parts:
- The primary logical unit protocols (specified with the PRIPROT operand of the MODEENT macroinstruction) apply to the primary end of the session.
- The secondary logical unit protocols (specified with the SECPROT operand of the MODEENT macroinstruction) apply to the secondary end of the session.
- The common logical unit protocols (specified with the COMPROT operand of the MODEENT macroinstruction) apply to both the primary and secondary ends of the session.
The 2 bytes describing the primary and secondary logical unit protocols have the same format; however, different bits can be on or off depending upon the protocol used and how it applies to the specific end of the session being described by the byte.
The format of the function management usage field is described
in SNA Technical Overview and is also shown in Table 2 (see the primary, secondary, and
common protocol fields). An overview of the use of many of the indicators
in this field is given in Communicating with logical units.
More detailed information about the function management usage field
can be found in SNA Sessions Between Logical Units and SNA
Concepts and Products