Sebastian, Thanks for your contribution to this rolling mystery.
Perhaps my Googling went of course by starting with ADCD. URL http://dtsc.dfw.ibm.com/MVSDS/'HTTPD2.adcd.global.html(readme17)' led me into thinking that the base system was FLEX-ES. I am dimly aware there are other such platforms so perhaps ADCD also runs on a Hercules if port 3270 is specific to Hercules. I did notice that FLEX-ES documents kept mentioning port 24 - but it's easy enough to change ports - if the software sticks to the "goodness" convention of always using the getservbyname() call and the /etc/services file is modified appropriately. Perhaps the ADCD package somehow thought that it would be cleverer to use port 3270 in order to access the local non-SNA channel-attached 3270 emulation. That paragraph has at least one too many "perhaps's" in it for comfort. Now I do know about VTAM and I'm afraid you are wrong about the USS table - or maybe just not quite precise enough. You don't get just the first USS table. What you get is the first USS table that has the name as specified in the - in this case - LOCAL statement in the VTAMLST member which defines the local non-SNA channel-attached 3270 devices using the USSTAB operand. Also if you are using the CS IP TELNET server for 3270 access you will get the USS table specified in the TELNET parameters. This USS table has to come from a load module partitioned data set which can be accessed by the appropriate CS IP procedure. This may be a dataset with VTAMLIB in the name but it is NOT the VTAMLIB concatenation by which you imply the VTAM procedure using VTAMLIB as a DD-statement name. If you are using some TELNET server for 3270 access where the server emulates a, say, 3174 with attached display devices then you can get the USS tables as defined to VTAM for those emulated LUs, probably from "switched" definitions in VTAMLST which can have USSTAB operands along with SSCPFM=USSSCS. This cannot happen in the case of the CS IP TELNET server since the 3270 devices are emulated by means of APPL statements in VTAMLST which cannot have USS tables associated with them. I wonder if you have read the rest of this thread from the beginning. Johnny rather confused us by equating the use of port 23 and port 3270. He tells us he changed the USS table in the VTAMLIB concatenation and saw his changes using port 3270 but did not see that changes when using port 23 and he is surprised by the difference: <snip from post from Johnny Luo of Sunday, 08 January, 2006 10:38 AM> However, after re-IPL, the new logon screen only works when you connect to it using port 3270. On the other side, if you use TCPIP port 23, the logon screen is still the old one. Why does this happen? <end of snip> In my ignorance of these wonderful platforms for running z-software on emulated z-hardware, I assumed, faced with this perhaps accidental disingenuity, that we were talking about the same IP address being used in both cases. According to your information this cannot be the case. "Loopback" is used in order to access the FLEX-ES (and, I expect, the Hercules) TELNET 3270 server from the TELNET 3270 client - only assumed to be x3270 from the FLEX-ES references I found - while some address associated with the z-operating system is used to access the operating system's, in this case z/OS CS IP, TELNET 3270 server. That's why - in the second paragraph of my post which you did not include - I speculated over some sort of "passthru" facility that would allow some ports to be reflected through to the supported operating system instances supported by something like a NAT table if port translation was required. I'm reminded of another quotation which can so often apply to anything to do with these "smoke and mirrors" techniques, from Alexander Pope this time rather than Sir Walter Scott: "A little knowledge is a dang'rous thing" Chris Mason ----- Original Message ----- From: "Sebastian Welton" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <[email protected]> Sent: Monday, 09 January, 2006 5:21 PM Subject: Re: Manuals on modifying VTAM logon screen? > On Mon, 9 Jan 2006 13:59:27 +0100, Chris Mason <[EMAIL PROTECTED]> wrote: > > >Well, I have been doing some Googling and I now see what your - and > >Terry's - system is all about. It appears that I was correct in guessing > >that "port 3270" enables you to be pretending to be a local non-SNA > >channel-attached 3270 display device represented in VTAM by a LOCAL > >statement necessarily using a USS table with USS message text consisting of > >the 3270 data stream. It seems that FLEX-ES provides a TELNET 3270 server - > >what Terry calls the "Telnet Listener" - which provides the appearance of > >this local non-SNA channel-attached 3270 display device to the supported > >operating system, in this case z/OS. > > FLEX-ES provides something called the 'Terminal Solicitor' which gives you > access to local non-SNA terminals which are defined in the configuration > file. To use the 'Terminal Solicitor' you would telnet to port 24 of the > host operating system. x3270 is the standard 3270 emulation package which is > installed with FLEX-ES and you can connect directly to your S/390 OS from > the laptop by doing a telnet to localhost (or 127.0.0.1) which will give you > the first USSTAB in your VTAMLIB concatenation. > > If however you have configured your system so that an ethernet adapter is > emulating, for example, a 3172 then you can directly telnet in to the IP > address of you S/390 OS, which would by default be port 23. Once again you > will get the first USSTAB in your VTAMLIB concatenation unless you have > created a new USSTAB for TCPIP and modified your TCPIP PROFILE to point to > this USSTAB. Exactly like 'big iron.' > > If anyone is using port 3270 I suspect they are using Hercules. > > Sebastian. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
