you will find a range of MTU sizes in radio links of various sorts which is not just 802.11 but also cellular including GPRS CDMA and WCDMA. Now, in many instances there is a proxy between the mobile station and the public network. In fact I wrote a powerpoint presentation summarizing such a paper on transparent TCP proxy in WCDMA and its on my site http://www.networkengineer.biz (I took a course in wireless architecture). On Thu, 21 Jul 2005, Darren Reed wrote: > In some mail from Fernando Gont, sie said: > > > > At 07:25 p.m. 20/07/2005, Darren Reed wrote: > > > > >In some mail from Fernando Gont, sie said: > > > > The IPv4 minimum MTU is 68, and not 576. If you blindly send packets > > > larger > > > > than 68 with the DF bit set, in the case there's an intermmediate with an > > > > MTU lower that 576, the connection will stall. > > > > > >And I think you can safely say that if you see any packets trying to > > >indicate that the MTU of a link is "68" then you should ignore it. > > > > Yes. But what about 296? > > > ... > > >I think it is reasonable to say anyone trying to advertise an MTU less > > >than 576 has nefarious purposes in mind. > > > > There are still some radio links with MTUs of 296 bytes. > > Go search with google....people still actively use smaller MTUs. > > What do you do? Where do you draw the line in the sand? > > Darren >
