MTU of the Internet?

Wed Feb 4 19:02:40 UTC 1998

On Wed, 4 Feb 1998, Dirk Harms-Merbitz wrote:

> Could be related to dialup people wanting lower latencies in
> multiplayer games.
> 
> Dirk
> 
> On Wed, Feb 04, 1998 at 12:05:29PM -0500, Perry E. Metzger wrote:
> > 
> > Peter Ford writes:
> > > Several people have noted to the Microsoft Support and Product groups that
> > > they want the Windows 95 PPP MTU to be set to 576 (down from 1500).  this
> > > change is in Windows 98.
> > > 
> > > The reason for this change cited by many customers is that many ISPs have
> > > 576 MTUs set "inside" their networks and packets get fragmented.
> > 
> > I know of no modern networking media in common use at ISPs that has an
> > MTU below 1000, and have not heard of ISPs with MTUs that low. Also,
> > the ISP's PPP could simply negotiate the MTU down -- it need not
> > accept a large MTU, no matter what Windows would like. The entire
> > story sounds, to say the least, fishy.
> > 
> > BTW, if Windows 95 is doing path MTU discovery, it should all be
> > irrelevant.
> > 
> > Perry
> 

brad reynolds
ber at cwru.edu