Effects of the MAXIMUM option
The MAXIMUM attribute of the SESSIONS resource specifies the maximum number of sessions that can be supported for the modegroup, and the number of these that are supported as contention winners.
Operation of APPC connections is made easier if the maximum number of sessions at each end of the connection match, and the number of contention-winner sessions specified at the two ends add up to this maximum number. If this is done, CNOS negotiation does not change the numbers specified.
If the specifications at each end of the connection do not match, as has just been described, the actual values are negotiated by the LU services managers. The effect of the negotiation on the maximum number of sessions is to adopt the lower of the two values. An architected algorithm is used to determine the number of contention winners for each partner, and the results of the negotiation are reported in messages DFHZC4900 and DFHZC4901.
These results can also be deduced, as shown in Table 1, by issuing a CEMT INQUIRE MODENAME command.
| Display | Interpretation |
|---|---|
| MAXimum | The value specified in the sessions definition for this modegroup. This represents the true number of usable sessions only if it is equal to or less than the corresponding value displayed on the partner system. |
| AVAilable | Represents the result of the most recent CNOS
negotiation for the number of sessions to be made available and potentially
active. Following the initial CNOS negotiation, it reports the result of the negotiation of the first value of the MAXIMUM option. |
| ACTive | The number of sessions currently bound. |
To change the MAXIMUM values, release the connection, set it OUTSERVICE, redefine it with new values, and reinstall it.