This is a selector identifying the current synchronization
source. Usually this will be a pointer to a structure
containing the peer variables. The special value NULL indicates
There is no currently valid synchronization source.
hh3cNTPSysPeer is replaced by hh3cNTPSysSrcPeer. Reading
hh3cNTPSysPeer might fail because the syntax value range is limited,
for example, when the synchronization source IP address is a Class C
address.