[ns] tcpUnixPort.h not found corretcly

Hi, all,
I have downloaded the package ns-allinone-2.35. Here is my steps to
install NS-2.
First cd to directory tcl8.5.10, type commands:
./configure
make
sudo make install,
Then cd to directory tk8.5.10, type commands:
./configure
make
sudo make install

The results of the above commands report no errors.

Thirdly, cd to directory otcl-1.14, type command:
./configure
and no error happend.
Then make, but terminated with:
---------------------------------------
gcc -c -g -O2 -DNDEBUG -DUSE_SHM -DHAVE_UNISTD_H=1 -I.
-I/home/jfhu/Downloads/ns-allinone-2.35/tk8.5.10/generic
-I/home/jfhu/Downloads/ns-allinone-2.35/tcl8.5.10/generic
-I/home/jfhu/Downloads/ns-allinone-2.35/tcl8.5.10/generic
-I/usr/includes/X11 -I/include otcl.c
In file included from
/home/jfhu/Downloads/ns-allinone-2.35/tcl8.5.10/generic/tclInt.h:36:0,
from otcl.c:21:
/home/jfhu/Downloads/ns-allinone-2.35/tcl8.5.10/generic/tclPort.h:25:28:
fatal error: tclUnixPort.h: No such file or directory
compilation terminated.
-----------------------------
THe file tclUnixPort.h is under
/home/jfhu/Downloads/ns-allinone-2.35/tcl8.5.10/unix which is not
within the include path of GCC.
So may be the configuration is wrong, or I miss some steps?
Hope make myself clear

Thanks,

Jfhu