Pat, A VTAM application, in effect, has access to the SSCP-LU session by means of the TERMSESS macro. Here's some text from the CS SNA Programming manual:
"The TERMSESS macroinstruction terminates sessions in which the application program acts as the SLU. The RPL OPTCD operand specifies the type of session termination desired by the application program: OPTCD=COND causes a Terminate Orderly request to be sent to the SSCP. OPTCD=UNCOND causes a Terminate Forced request to be sent to the SSCP. OPTCD=UNBIND causes an UNBIND to be sent to the PLU." I copied this so that you can see how those OPTCD values map to the USS TYPE options. Thus the CS IP TN3270E support could make a better fist of supporting the USS LOGOFF function. This doesn't depend on the RFC. The RFC merely says that the possibility to break into an existing LU-LU session and do something, typically "logoff", is catered for. As you know I'd like proper USS support so that you could induce the appearance of USS messages, particularly USS message 5 by entering nothing. This isn't a compatibility issue since the RFC just says the window is there. It's up to the particular server implementation what use it can make of it - but you've raised a doubt so I'll read the RFC and get back if I need to - I'll probably get back for some reason anyhow :-) Also I think I may have asked for too much by suggesting that "ibmtest" could be supported. In fact running an echo from the TELNET server rather than VTAM itself is close enough to perform the desired function of "ibmtest". "ibmtest" is a nostalgia item for me since I was involved in a 1969 project to provide just this function for BTAM terminal devices "stolen" from their application - but the program had to be using the famous "multiple wait" ... Chris Mason ----- Original Message ----- From: "Patrick O'Keefe" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <[email protected]> Sent: Wednesday, 18 January, 2006 9:55 PM Subject: Re: TN3270 Question > On Mon, 16 Jan 2006 16:16:40 +0100, Chris Mason <[EMAIL PROTECTED]> > wrote: > > >... > >Once you do find the SysRq key, you can enter "logoff" without the > quotation > >marks* and VTAM, performing its SSCP role, will terminate the session > >between the application and the TELNET logical unit (LU) managed by the > >TELNET 3270 server. Ideally you could have the possibility to determine > the > >degree of "prejudice" you apply to the session termination request by > >specifying whether the application is to be asked politely, TYPE(COND) - > >COND for conditional, rudely, TYPE(UNCOND) - UNCOND for unconditional, or > >the application is to be given no chance to refuse, TYPE(FORCE). > >... > > Chris, > > Your posting prompted me to dig into the Tn3270E RFCs (1647 & 2355) a bit. > I don't see any updates to SysReq in 2355. RFC 1647 states that the > behavior of the server to a SysReq depends on whether the server has > access to the SSCP-LU session. An outboard emulator that looks like a > 3270 controler has access to that session; the zCS Tn3270 server does not; > it is simply a VTAM appl with an open ACB. (If defined with AUTH=CNMI I > guess it would have access to some SSCP functions, but I don't think > that was included in the design.) For servers without access to the > SSCP-LU function a very limited SysReq support is implemented. You can > toggle out of the LU-LU session and back (generating the 082B sense you > mentioned) and you can request LOGOFF which will generate UNBIND > Normal). > > The other things you mention are definitely not there, but they are not > supposed to be there according to the RFC. Servers could add extensions > (like the device support you discovered) but moving too far from the RFC > raises incompatability problems. > > Pat O'Keefe ---------------------------------------------------------------------- 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
