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Conference turris::digital_unix

Title:DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:Welcome to the Digital UNIX Conference
Moderator:SMURF::DENHAM
Created:Thu Mar 16 1995
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:10068
Total number of notes:35879

8545.0. "NFS - tcp vs udp" by RHETT::AMAN () Wed Jan 22 1997 14:28

T.RTitleUserPersonal
Name
DateLines
8545.1Tcpdump traces?NETRIX::"[email protected]"Ric WermeMon Jan 27 1997 10:1825
    nfs3: rfs3_lookup: failed for server <server>
    RPC: Can't decode result

I wrote the NFS over TCP code, but have no good explanation for this.
There are a couple glitches, but I don't think they explain this.  Are
client or server SMP?

Tcpdump traces would be helpful, (see note 2328), but tcpdump will often
lose synchronization with NFS over TCP reads and writes as it only looks
for NFS requests at the beginning of packets.

While TCP is reliable and UDP unreliable, RPC provides most of the reliability
in UDP.  The NFS over TCP is better in congested networks (TCP implementations
can do better congestion control) and TCP's fast retransmit algorithm often
provides better performance in lossy/errorful environments.

Improved reliability was not a major design goal, as the NFS community has a
decades experience with coexisting with UDP.  Better behaviour of WANs was the
primary goal.

N.B. The Notes/news gateway for dec.notes.basesys.unix appears broken - Email
will get answers faster.


[Posted by WWW Notes gateway]
8545.2thanks for the inputRHETT::AMANMon Jan 27 1997 17:2411
    Thanks for that information in .1.  I'll see if the customer wants to
    pursue an answer for this error.  I've asked him for tcpdump output
    during the occurance of the errors.  I guess the most disturbing thing was
    that once the error occured, the client completely locked up and it had
    to be rebooted...
    
    Thanks again!
    janet