The group size (default value 1) represents the maximum number of data modifications that can be bundled into a single update message. If the network connection appears to be impeding replication, increase the group size to a higher value than the default, such as 10, and recheck replication performance.
When increasing the group size, make sure that the following are true:
The window size is set significantly higher than the group size.
The window size divided by the group size is much greater than the value for nsslapd-maxThreadsPerConn under cn=config on the consumer (typically twice as large).
When the group size is set higher than 1, the supplier does not wait to fill a group before sending updates to the consumer.
You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.