[ns] warning:deprecated conversion from string constant to 'char*

[J S]

Hello I am new to ns.

I have been following "NS by example tutorial" from http://nile.wpi.edu/NS/

In the sub-section extending NS (for user define agents), While using make,
I am getting bunch of warnings

./common/packet.h:: warning: deprecated conversion from string constant to
'char*'

I am using ubuntu.

Any help in this matter is appreciated

Thanks you