DirectConnect requires the GCC C++ runtime libraries installed in your system. If DirectConnect fails to start due to libstdc++.so inability to do so, install the GCC C++ runtime libraries on your machine and include its library directory in the LD_LIBRARY_PATH of your shell.
If you use the $SYBASE/DC-15_0/DC_SYBASE.csh script to set your environment, append the GCC C++ library directory to the LD_LIBRARY_PATH setting in that file. For example, an edited LD_LIBRARY_PATH in DC_SYBASE.csh may read as follows:
setenv LD_LIBRARY_PATH ${SYBASE}/DC-15_0/lib:${SYBASE}/DC-15_0/connectivity/OCS-15_0/lib:${SYBASE}/15_0/connectivity/OCS-15_0/lib3p:/usr/lib/lwp:/usr/lib:${SYBCSI_PROVIDER_DIR}:${LD_LIBRARY_PATH}:/opt/hp-gcc-4.2.1/lib/hpux64