Re: IESG review: direct MAC encapsulation

[Emmanuel Duros <Emmanuel.Duros@UDcast.com>]

Tim Gleeson wrote:
> 
> > 5. > 8.2. Encapsulation of UDL MAC level packets
> > >
> > >    An alternative is to encapsulate the MAC level packet within IP. The
> > >    protocol field in the IP datagram is then set to the MAC type of the
> > >    unidirectional link. Figure 5 presents the entire encapsulated
> > >    packet.
> > >
> > >            ----------------------------------------
> > >            |           IP delivery header         |
> > >            |        destination addr = FBIP       |
> > >            |    IP proto = MAC type of the UDL    |
> > >            ----------------------------------------
> > >            |            Payload packet            |
> > >            |             MAC packet               |
> > >            ----------------------------------------
> > >
> > >                  Figure 5: Encapsulated packet
> >
> > I think this section should just be removed. We don't have enough IP
> > protocol values to do this in general, and I suspect any tunneling
> > scheme for doing link-layer above IP would require its own RFC anyway
> > to nail down some of the details. Why is this any better than using
> > GRE? Are there implementations of this in products?
> 
> Does anyone do this?
> 
> Do we lose anything by junking this? 

As far as I know, all the implementations I have seen do not implement this
encapsulation format. It would also be very sensible not to waste IP protocol
numbers. Let's remove it if no one is opposed. GRE does the job very well.

> I think it was just in there as a
> "how it might be done" description. As pointed out, there's
> potentially a lot of paperwork to make it complete. In which case that
> should probably be done on bits of paper other than this one.
> 
> Tim

Emmanuel
--
UDcast: Where IP and UniDirectional links meet      http://www.UDcast.com