[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [ns] addition to ip hdr







>I think that's in ns-packet.tcl:

I believe that by removing header types from ns-packet.tcl, this makes this
protocol unavailable to the simulation.  This implies that the header for
every protocol used in a particular simulation is included in every packet
sent.

>Yes, it is. But then it's up to the user to define wich protocols he wants
to
>use. I just can't imagine a simple way to do this.

Without knowing very much about the internals of ns, I can say that I
believe the xkernel does this.  That is, the xkernel has explicit
'multiplexing' and 'demultiplexing' that tack on and remove headers much
like is done in a real networking implementation.  This means that packets
that are constructed *look* like those that would be actually transmitted.
TCP packets for example contain the mac header, IP header, and TCP header
only.  As in a real implementation, packets are passed from one layer to
the next where a packet header is either added or removed.  Why couldn't
the packet building functions of ns do the same?  Again, I don't know
enough about ns to answer that.....

regards,


Adolfo