Re: SDU setting - tnsnames, listener.ora

From: saar <sxmaxoz_at_us.oracle.com>
Date: Fri, 19 Jun 1998 10:55:52 -0700
Message-ID: <358AA627.E167F603@us.oracle.com>

Chris Kempster wrote:

> Does anyone know what SDU means?, the parameter can be used in the tnsnames
> and listener.ora files and has a default value of 4Kb (to 32Kb).

SDU is Session Data Unit
TDU is Transport Data Unit
(read on ISO 7 layers)

you must change on both client (tnsnames.ora) & server (listener.ora) otherwise smaller value will be used.
syntax is:

client:
alias = (DESCRIPTION=

                        (SDU=4096)
                        (TDU=4096)
                        (ADDRESS= ...  )
                        (CONNECT_DATA= (SID=test)))

server:
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =

      (SDU=4096)
      (TDU=4096)
      (SID_NAME = test)
       (...rest of stuff..)

> After some
> prelim testing is can improve sql*net connectivity from client to server
> from about 5 to 20%.

Look at following two stats to indicate whether playing with these parameters will help:

SQL*Net more data to client
SQL*Net more data from client

If they are clibming then set SDU TDU to higher values, this will prevent SQL*Net
from breaking a packet into smaller ones. less packets faster response...most of the time...

Saar.

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Received on Fri Jun 19 1998 - 12:55:52 CDT