Subject: Re: NFS problem.
To: Steven M. Bellovin <smb@cs.columbia.edu>
From: Johnny Billquist <johnny.billquist@softjar.se>
List: current-users
Date: 12/10/2005 18:44:29
Steven M. Bellovin wrote:
> In message <dne4vq$qbc$1@serpens.de>, Michael van Elst writes:
>
>>tron@zhadum.org.uk (Matthias Scheler) writes:
>>
>>
>>>Yes, but it hasn't changed and never will. Large UDP packets are sent
>>>as IP fragments. If you lose one of the IP fragments the whole UDP
>>>packet is lost because there is no selective retransmit. When a machine
>>>e.g. loses 5% of incoming packets at least one of the IP fragments
>>>of a 32KB UDP packet will always get lost. Retries will not help because
>>>another single lost packet will prevent the reception of the UDP packet.
>>
>>On the other hand, TCP isn't exactly fast with 5% packet loss either.
>
> Right, but TCP adapts its sending rate to the level that avoids packet
> loss.
Exactly how does it do that in this instance?
We're talking about the fact that if we send back to back packet on the
net, we have a limit of (in this case I believe) 2 packets. All other
situations will work fine.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt@update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol