[c-nsp] What MTU for Bellsouth BBG / BRAS <-> LNS l2TP tunnel?

[Ueli Heuer]

as long as the IP MTU of the 10/100 ethernetsegment ist fixed to max
1500 byte you'll use some bytes for the PPPoE encapsulation and these
bytes are missing in the paylod.
the problem are firewalls- administrators (and vendors) who think
_all_ icmp-packets are bad and they block  any icmp-messages.  so the
source will not be notified to send smaller packets.


On Thu, 28 Oct 2004 10:59:48 +0200, Gert Doering <gert at greenie.muc.de> wrote:
> Hi,
> 
> On Thu, Oct 28, 2004 at 11:42:14AM +1000, Ash Garg wrote:
> > This gives me 10-12 bytes "extra" in the IP packet and 8 bytes "extra" in
> > the AAL5 frame which covers any weird stuff that may occur and does not "I
> > think" put extra load on the LNS.
> 
> Just leaving the ATM MTU at 4470 won't cause any extra load either.
> 
> gert