Re: New Internet Draft on automatic (end-user) tunneling for SSM

[jhall@UU.NET (Jeremy Hall)]

Maybe I'm missin somethin obvious, but why encapsulate the original packet
inside a UDP packet and THEN inside a GRE packet? Wouldn't it make more
sense to just encapsulate the original thing in a GRE packet?

_J

In the new year, Ross Finlayson wrote:
> At 02:07 AM 2/24/01, Dino Farinacci wrote:
> > >>  From my understanding of GRE (please correct me if I'm wrong), the
> > >> overhead to tunnel an arbitrary UDP multicast packet using GRE would 
> > be 32
> > >> bytes: 4 bytes (for the GRE header), plus 28 bytes (for the UDP/IP 
> > headers
> > >> of the encapsulated packet).
> >
> >     The overhead is an additional 24 bytes (20-byte fixed IP header and 
> > 4-byte
> >     GRE header).
> 
> But what about the UDP header of the packet that's being tunneled (i.e., 
> the inner packet)?  That's another 8 bytes.  Wouldn't that go in the GRE 
> packet as well?
> 
>          Ross.
>   
>