Re: SDU setting being ignored?

From: Tim Gorman <>
Date: Wed, 28 Jan 2009 15:19:21 -0700
Message-ID: <>



On the client-side TNS connect-string, I've always specified the SDU clause within the first level of the DESCRIPTION, outside both the ADDRESS_LIST/ADDRESS clause as well the CONNECT_DATA clause.

So, using your example...
Hope this helps...
Tim Gorman
consultant - Evergreen Database Technologies, Inc.
P.O. Box 630791, Highlands Ranch CO  80163-0791
website   =
email     =
mobile    = +1-303-885-4526
fax       = +1-303-484-3608
Yahoo IM  = tim_evdbt

Rich Jesse wrote:
Hey all,

Yes, I'm traveling down the dark path of Oracle traffic over a WAN. 
Naturally, I want to test changing the SDU to optimize it.  Client is 32-bit
WinXP, server is AIX 5.3TL8 and both are using v10. Oracle.

To test, I added these entries to $OH/network/admin/listener.ora on the server:


  (SID_LIST = (SID_DESC = (SDU = 8192)(SID_NAME = mydb)))

I then started the MYDBWAN listener, so as not to affect connections to the
default listener:

lsnrctl start mydbwan

On the client's %OH%\network\admin\tnsnames.ora, I added:


I enabled a net trace in the client's sqlnet.ora.  When connecting to
MYDBWAN from SQL*Plus, the trace has:

[28-JAN-2009 13:01:15:966] nsc2addr:
[28-JAN-2009 13:01:15:966] nttbnd2addr: entry
[28-JAN-2009 13:01:15:966] nttgetport: entry
[28-JAN-2009 13:01:15:966] nttgetport: port resolved to 1526
[28-JAN-2009 13:01:15:976] nsopen: lcl[0]=0xf4ffefff, lcl[1]=0x102000,
gbl[0]=0xfabf, gbl[1]=0x0, tdu=32767, sdu=2048

Still only 2048!  I've tried changing "SERVICE_NAME" to "SID" in the
tnsnames.ora, selecting different values for SDU on both client and server,
and bouncing the listener in between each change.  But I can't confirm that
SQL*Net's using a non-default SDU value.

I've searched the Oracle Net Admin Guide, Metalink, and the List archives,
but no luck.  I think the last time I messed with this was in the Fatcity

Thoughts anyone?



-- Received on Wed Jan 28 2009 - 16:19:21 CST

Original text of this message