[Ns-developers] Csma, ethernet length field, NSC and the linkmtu...

[Mathieu Lacage]

On Wed, 2008-07-23 at 13:37 -0700, craigdo at ee.washington.edu wrote:
> [ ... ]
> 
> > SetMtu is expected to fail and return false if the value given is not
> > compatible with the configuration of the underlying device. 
> > Now, if you
> > make the Mtu an attribute, you will need to make sure that 
> > setting that
> > value through the attribute system conforms to the device's 
> > bounds and,
> > if these bounds are not static (as is the case for the csma netdevice
> > which can be dynamically configured to behave in different ways), you
> > will have to provide your own implementation of AttributeChecker which
> > performs bounds checking based on the device's configuration.
> 
> I think this means we agree.  Let me reiterate:
> 
> o No notion of separate PHY and MAC MTU numbers exist in either p2p or CSMA
> devices;
> o There should be an internal PHY MTU which corresponds to the 1500 byte
> enet number;
> o There should be a mac level MTU attribute checked against the Phy MTU;
> o SetMtu should attempt to set the Mac MTU and return error if it can't;
> o GetMtu should return the MAC MTU which is the payload;
> o What we're talking about should be explicitly stated in the dox.

yes.

Mathieu