This is tested to work better in at least one firewalled environment. YMMV.
wget -c http://ftp.gnu.org/gnu/gcc/${GCC}/${GCC}.tar.bz2
echo "Downloading newlib sources..."
wget -c http://ftp.gnu.org/gnu/gcc/${GCC}/${GCC}.tar.bz2
echo "Downloading newlib sources..."
-wget -c ftp://sources.redhat.com/pub/newlib/${NEWLIB}.tar.gz
+wget -c --no-passive-ftp ftp://sources.redhat.com/pub/newlib/${NEWLIB}.tar.gz
echo "Downloading gdb sources..."
wget -c http://ftp.gnu.org/gnu/gdb/${GDB}.tar.bz2
echo "Downloading gdb sources..."
wget -c http://ftp.gnu.org/gnu/gdb/${GDB}.tar.bz2