When a data recipient receives packets correctly, the recipient sends a delayed acknowledgment to the sender of the data. When AIX 5L is used, by specifying the OS parameter (tcp_nodelayack), an acknowledgement can be sent immediately upon receipt of packets. This setup improves the response delay situation that occurs during communication processing. However, specifying OS parameters affects the entire system.
Specifying the following definitions allows immediate acknowledgement to be used only for HiRDB communications. Note however that immediate acknowledgment is not used for communication other than HiRDB on AIX 5L.
Specifying these definitions (pd_ipc_tcp_nodelayack=Y and PDNODELAYACK=YES) are effective only when AIX 5L V5.2 with the IY51819 patch applied or AIX 5L V5.3 and later are used.
Figure 25-12 shows the object of immediate acknowledgment.
Figure 25-12 Object of immediate acknowledgment