RE: AS/400 IP COMMUNICATION WAIT TIME -- MIDRANGE-L

True you may be able to disconnect a client tcp/ip from the network and plug
back in without loosing the connection.  But a server is different.  You may
get away with it, but if someone sends data to the server while the
connection is broken, the client will close their side of the connection.
If you tried to refresh your tcp/ip telnet screen while the laptop was
disconnected you would have lost everything.  I have switched my AS400 from
one hub to another hub with only losing a couple of connections, we have
several hundred active all the time.

So the answer is YES you can disconnect the as400 Ethernet line and then
re-connect, but results may be unpredictable.



Christopher K. Bipes     mailto:ChrisB@Cross-Check.com
Sr. Programmer/Analyst   mailto:Chris_Bipes@Yahoo.com
CrossCheck, Inc.         http://www.cross-check.com
6119 State Farm Drive    Phone: 707 586-0551 x 1102
Rohnert Park CA  94928 Fax: 707 586-1884

*Note to Recruiters
Neither I, nor anyone that I know of, is interested in any new and/or
exciting positions. Please do not contact me.


-----Original Message-----
From: Carl Galgano [mailto:cgalgano@ediconsulting.com]
Sent: Friday, January 07, 2000 6:42 AM
To: MIDRANGE-L@midrange.com
Subject: Re: AS/400 IP COMMUNICATION WAIT TIME


Bob/Jim:
Why then when I disconnect my laptop which is connected to my AS400 via IP,
and move to a different office in my building and plug back into the network
that I still have the same session connect.  It never misses a beat?
CJG

Carl Galgano
EDI Consulting Services, Inc.
540 Powder Springs Street
Suite C19
Marietta, GA  30064
770-422-2995
mailto: cgalgano@ediconsulting.com
http://www.ediconsulting.com
EDI, Communications and AS400 Technical Consulting

-----Original Message-----
From: Bob Crothers <bob@cstoneindy.com>
To: MIDRANGE-L@midrange.com <MIDRANGE-L@midrange.com>
Date: Friday, January 07, 2000 8:41 AM
Subject: RE: AS/400 IP COMMUNICATION WAIT TIME


>Jim,
>
>You've got it mostly right.  Except the part about TCP being "Connection
>Based".  It does not have to be that way.  Look at HTTP.  The connection is
>not maintained for the duration of the session.  Only while data is being
>exchanged.  Other protocols/applications are different.  Telnet is
>connection based.  FTP is actually both.  The control part of the
>conversation is connection based, but data is exchanged over a
>connectionless conversation.  And custom applications can be how ever you
>want them.
>
>The main difference between TCP & UDP is that when you send data via TCP,
it
>is guaranteed to not only arrive at the destination (or cause an error) but
>also in the same order you send it.
>
>When you send with UDP, not only is the data NOT guaranteed to arrive at
the
>destination, but the data MIGHT be out of order.  As a result, UDP tends to
>be used for "trivial" things (like ping) or broadcast where each byte of
>data is not that important (streaming sound/video).
>
>Bob
>
>-----Original Message-----
>From: owner-midrange-l@midrange.com
[mailto:owner-midrange-l@midrange.com]On
>Behalf Of Jim Langston
>Sent: Thursday, January 06, 2000 6:13 PM
>To: MIDRANGE-L@midrange.com
>Subject: Re: AS/400 IP COMMUNICATION WAIT TIME
>
>Short answer: it is not possible to disconnect without the clients
>"knowing".
>
>Long answer:
>TCP is a connection scheme.  When using TCP/IP the connection
>remains open.  Once the communication between the server and
>the client is closed, the TCP/IP connection is closed.  UDP, on
>the other hand, is a broadcast scheme.  There is no permanent
>connection.
>
>Since the majority of IP communication is TCP based (including
>client access and the like) if you disconnect the cable from either
>the server or the client the channel is closed, and the program
>errors out, either graceful with a window saying the session has
>been terminated, or ungraceful for programs not looking for this.
>
>Once you disconnected and reconnected, the connections would
>have to be re-established.
>
>Regards,
>
>Jim Langston
>
>oludare wrote:
>
>> Hi Guys, I need to know.  Is it possible to disconnect the RJ45 that
>> connects all CLIENTS (PCs) to the AS/400 box, communicating over IP,
>> and reconnect back without any CLIENT knowing that communication was
>> interrupted.  What happen to all active interactive jobs (programs)
>> from the PCs and Session Manager? Thanks for you help. Oludare
+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---