Identification of Topology..?

[Sriram Shanmugam]

Hai , 

    How do i identify the topolgy( Bus ,Ring , Mesh, ....) ? , i would like
to do this by writting a program i.e on the fly ,while the application
starts execution .Is there any clue in the data packets sent or recvd ?.

Regards,

S.Sriram