Point to Point Ethernet

Stephen Kratzer kratzers at pa.net
Wed Jul 8 14:57:06 UTC 2009


My first thought was that there's really no use ripping the guts out of a 
protocol whose core mechanisms are aimed at dealing with the complexities of 
operating on a shared medium only to use it in an environment in which none 
of those complexities exist.

But, if interfaces would be made to support both Ethernet II and some new 
Addressless Ethernet (or some other moniker) frames, the additional costs, 
real or administrative, wouldn't be outstanding.

You might want to first try proving that reducing the Ethernet frame overhead 
by 2/3 and, in turn, reducing the average frame size by 12 / [average frame 
size] percent is worthwhile. Or try making the frame overhead reduction 
argument only a small piece of the larger argument for getting rid of 
multi-access cruft in point-to-point environments. But good luck pushing the 
principle argument of making things "as simple as possible but no simpler" 
without good technical and (hence) business cases.

Stephen Kratzer
Network Engineer
CTI Networks, Inc.

On Wednesday 08 July 2009 06:01:20 Andre Oppermann wrote:
> A few time already I've wished for a fully standardized and vendor
> interoperable way of doing a true point to point ethernet link.
>
> It would work just like an old leased line or synchronous serial
> interface and completely do away with ARP, MAC addresses and all
> that stuff.  Obviously no switches in between would be allowed.
> Each side would run in "promiscuous mode" where every ethernet
> frame is received and passed up to the network stack (just like
> on a serial link).  Since MAC addresses are useless they can be
> scrapped and only the ethertype field remains.  This increases
> the effective MTU by 12 bytes.
>
> The framing overhead goes away and the packet can directly be
> directly placed on the wire without taking a detour through L3->L2
> lookup and encapsulation step.
>
> More importantly one can specify the just the outgoing interface
> again instead of the next hop:
>
>   ip route 10.0.0.0 255.0.0.0 g0/1
>
> Do you think this is useful?  Maybe vendors will hear me/us.




More information about the NANOG mailing list