Constant used to translate between NTP time used in SDP and "native" Java time.
NTP time is defined as the
number of seconds relative to midnight, January 1, 1900 and Java time is
measured in number of milliseconds
since midnight, January 1, 1970 UTC (see System#currentTimeMillis()}).
The value of this constant is 2208988800L. It can be used to convert between
NTP and Java time using the
ntpTime = javaTime/1000 * SdpConstants.NTP_CONST;
javaTime = (ntpTime - SdpConstants.NTP_CONST) * 1000;
The Network Time Protocol (NTP) is defined in RFC 1305.