Option -p (Soft Shutdown) 
This option can be used to perform a soft shutdown of an SAProuter. SAProuter continues running on another port and can be administrated on this port, but does not accept any logon requests, and terminates automatically when no more clients are connected.
The port on which SAProuter was running before (default 3299) is now free. This is useful in the following cases:
You want to start a new SAProuter without closing all existing connections.
More connections are required than one SAProuter alone can handle (max. 1018).
If you enter the command saprouter -p, information is displayed telling you on which port SAProuter can now be administered, and the host on which SAProuter is running.
The standard port on which SAProuter is running is port 65000. If it is already assigned or if a port range was already defined for the SAProuter with option -M <min>.<max>. , a different port is selected.
Recommendation
You can start the SAProuter using the Option -r -Y <n>. This has the effect that the existing SAProuter is automatically moved to another port and a new SAProuter is started. The new SAProuter then accepts incoming connections on this port.