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HIS Telnet Passthrough RRS feed

  • Question

  • We have a project that may or may not fit the HIS model.

    ~ 400 users accessing an SNA host via proprietary desktop software and gateway.

    Host connections methods are limited. Host provider wants to move away from SNA and will only provide an ethernet/Telnet server access.

    Can you configure HIS to act as a pass-through device for TN3270 connections? SDLC and DLC host access is not available in the new model.

    Friday, March 23, 2012 1:57 PM

Answers

  • Hi Greg,

    You can choose if you want to use HIS or not but you should know that if you're using directly TN3270 on the Mainframe, the CPU consumption will increase (cost).

    One scenario could be using a TN3270 emulator connecting to the HIS TN3270 interface. This HIS 3270 interface will afterwards connect to the IPDLC connection in order to establish the 3270 connection with the host. In that scenario you will only use the SNA connection between HIS and the Mainframe.

    On the HIS server you can easily configure users / workstation that have access to a specific range of sessions.

    Let say you want to have 6 sessions per user. That means that in you case you will have 2400 sessions defined on the HIS server. This will be no problem for performance. In addition HIS offers you the possibility to monitor which user is connected to which session.

    Please let me know if you need more information ?

    Best Regards,


    Steve Melan - BCEE My Blog : http://stevemelan.wordpress.com

    Wednesday, April 4, 2012 6:13 AM

All replies

  • <style></style>
    Greg
     
    > We have a project that may or may not fit the HIS model.
     
    Which implies you are open to any other "model", doesn't it?
     
    > ~ 400 users accessing an SNA host via proprietary desktop software and gateway.
    > ... will only provide an ethernet/Telnet server access.
    > ... to act as a pass-through device for TN3270 connections ...
     
    This implies that the desktop platform (with assistance from some sort of "gateway"?) is running a client supporting TELNET with the 3270 data stream.
     
    Why not just leave HIS out of the configuration? It seems you want HIS to behave as some sort of IP router or even (ethernet) bridge!
     
    Incidentally, "ethernet" implies that the System z operating system and (server) programs are accessed through an OSA but, being simply a connection supporting TELNET with the 3270 data stream and hence IP, the media is irrelevant.
     
    > SDLC and DLC host access is not available in the new model.
     
    Note that this implies that the System z operating system is supporting something like z/OS, the IP component of z/OS Communications Server and the SNA-oriented TELNET server[1], TN3270E, provided with z/OS Communications Server. Thus all you need is the TELNET client function to be running in the "desktops".
     
    Mention of "SDLC" and (802.2) "DLC" imply that the System z was previously supported through a Communications Controller or possibly, in the case of "DLC", a 3172 (or an OSA feature configured for 3172 emulation).
     
    > Host provider wants to move away from SNA ...
     
    Of course, it's not moving "all the way"! You will still be using "fully-fledged" SNA protocols between the SNA-oriented TELNET server using the VTAM API and the application using the VTAM API possibly with the assistance of some session manager or other.
     
    -
     
    If your query need no longer involve HIS, you should subscribe the following list for further advice on supporting TELNET with the 3270 data stream using the SNA-oriented TELNET server:
     
    For IBMTCP-L subscribe / signoff / archive access instructions, send email to LISTSERV@VM.MARIST.EDU with the message: INFO IBMTCP-L
     
    -
     
    [1] the term "SNA-oriented TELNET server" contains a required qualification since the IP component of z/OS Communications Server also supplies an UNIX-oriented TELNET server.
     
    -
     
    Chris Mason
    Friday, March 23, 2012 3:57 PM
  • Greg,

    Yes, HIS can do this for you, easily. The host provider should be able to give you all the correct settings for an IP-DLC connection.


    Charles Ezzell - MSFT

    Monday, March 26, 2012 8:58 AM
  • <style></style>
    Greg
     
    >...> Host provider wants to move away from SNA ...
     
    This might be a "read my lips" moment!
     
    *If* - quite a large *if* - the "host provider" has already enabled VTAM for APPN and, even better, has already implemented "Enterprise Extender", what the "IP-DLC Link Service" is called by VTAM, Charles Ezzell's "easily" stands a chance of standing up in court.
     
    If the rather large *if* does *not* apply, the system programmer of the "host provider" is going to give you a blank stare when you ask for the "correct settings".
     
    Also for Charles Ezzell's benefit, it *cannot* be assumed that each and every "host provider" runs APPN-enabled VTAM and making the change from a subarea VTAM SNA configuration to an APPN-enabled VTAM SNA configuration is a major task - and is the very opposite of "move away from SNA".
     
    I keep making this point on this forum - as a very long-term VTAM/SNA specialist (since 1976) - but the Microsoft representatives routinely set no store by my contributions - tant pis!
     
    Chris Mason
    Monday, March 26, 2012 1:03 PM
  • Chris,

    It's all symantics. Greg asked a questioned. I answered it, without going into needless (for him) details. He doesn't (apparenlty) have a mainframe, could care less - he just needs to connect. All he knows is that his host provider is telling them we are dropping 'SNA" - notice he specificially mentioned DLC and SDLC were not available, which means 99.9% of the time when we get asked this type of question they are dropping the DLC protocol (or channel attached, or SDLC, or the other interfaces) and switching over to Enterprise Extender. While you may have great knowledge about VTAM, etc, it's obvious you know little about Host Integration Server and it's capabilities. We do appreciate your contributations, when necessary. We do not appreciate your remarks above, which you do seem to throw around a lot.


    Charles Ezzell - MSFT

    Monday, March 26, 2012 1:15 PM
  • <style></style>
    Charles
     
    > It's all symantics.[1]
     
    Rubbish. It's practicalities. I would have thought you would have been able to detect that
     
    > >...> Host provider wants to move away from SNA ...
     
    means that the installation is wanting to run down the need for SNA expertise and that
     
    > >...> SDLC and DLC host access is not available in the new model.
     
    means that the installation is in the process of removing Communications Controllers and NCP - and that any OSA features are configured with CHPID type OSD (IP support only with the richest set of functions) rather than CHPID type OSE (3172 emulation).
     
    > Greg asked a questioned.
     
    Yes.
     
    > I answered it, ...
     
    In a manner of speaking.
     
    > ... without going into needless (for him) details.
     
    The details are important for Greg if the system programmer hasn't the first clue what he is talking about. If you had mentioned "Enterprise Extender" rather than "IP-DLC", I'm going to assume - with every expectation in the light of
     
    > >...> Host provider wants to move away from SNA ...
     
    of being correct - that, once the system programmer had got some advice regarding implementing Enterprise Extender - assuming he or she didn't know already, Greg would be sent away with a flea in his ear!
     
    > He doesn't (apparenlty) have a mainframe, could care less - he just needs to connect.[2]
     
    Needing to connect in this case means "caring" for what he is asking. You absolutely refuse to take on board that implementing Enterprise Extender is a major upheaval in VTAM, don't you?
     
    >  All he knows is that his host provider is telling them we are dropping 'SNA" ...
     
    Noted frequently.
     
    > ... - notice he specifically mentioned DLC and SDLC were not available, ...
     
    Also noted frequently.
     
    > ... which means 99.9% of the time when we get asked this type of question they are dropping the DLC protocol (or channel attached, or SDLC, or the other interfaces) and switching over to Enterprise Extender.
     
    Rubbish. This may be what you have seen in the few cases you have encountered. However - and I won't hazard any precise percentages - this "smells" of eliminating all SNA outside the data centre, "glass house". In other words, it presupposes that the concatenation of the SNA session to the TELNET TCP connection happens using the SNA-oriented TELNET server provided by the IP component of z/OS Communications Server, assuming z/OS.[3]
     
    Perhaps Greg - or the system programmer to whom I referred above - can get back to use and assure us
     
    a) either that they are investing in the effort to enable APPN thereby not at all "move away from SNA"
     
    b) reducing all SNA footprint to the "glass house" which corresponds to "move away from SNA"
     
    c) something else
     
    > While you may have great knowledge about VTAM, etc, it's obvious you know little about Host Integration Server and it's capabilities.
     
    This would be a valid observation if this query didn't combine the limitation "move away from SNA" with your suggestion to implement Enterprise Extender which negates the possibility that the query concerned purely some capabilities of HIS. However it doesn't so the observation is pointless.
     
    If you have been following my contributions to this forum, you'll know I know quite a lot about the "IP-DLC Link Service" ever since I detected that the "white paper" makes such a mess of providing advice regarding interfacing with Enterprise Extender. I have even provided Microsoft with a set of corrections which show no sign of having been published so I reserve the right to be just as rude about the incompetence of Microsoft support as it concerns that interface as seems appropriate - as now!
     
    > We do appreciate your contributations, ...
     
    Well, act on them then - assuming you have some influence on HIS development.
     
    > ... when necessary.
     
    I don't waste time making unnecessary contributions as you should ... know!
     
    > We do not appreciate your remarks above, which you do seem to throw around a lot.
     
    Well you ... should pay some attention to all my always pertinent contributions and stop perpetually misleading your customers!
     
    -
     
    [1] Incidentally, it's "semantics" not "symantics"!
     
    [2] I take the trouble to "spell-check" my posts. It shows greater respect for my readers: apparenlty -> apparently, contributations -> contributions
     
    [3] If z/VM or z/VSE, there are equivalent SNA-oriented TELNET servers - and, by the way, the option to use Enterprise Extender does not exist! I wonder if you knew this!
     
    -
     
    Chris Mason
    Monday, March 26, 2012 7:02 PM
  • Hi Greg,

    You can choose if you want to use HIS or not but you should know that if you're using directly TN3270 on the Mainframe, the CPU consumption will increase (cost).

    One scenario could be using a TN3270 emulator connecting to the HIS TN3270 interface. This HIS 3270 interface will afterwards connect to the IPDLC connection in order to establish the 3270 connection with the host. In that scenario you will only use the SNA connection between HIS and the Mainframe.

    On the HIS server you can easily configure users / workstation that have access to a specific range of sessions.

    Let say you want to have 6 sessions per user. That means that in you case you will have 2400 sessions defined on the HIS server. This will be no problem for performance. In addition HIS offers you the possibility to monitor which user is connected to which session.

    Please let me know if you need more information ?

    Best Regards,


    Steve Melan - BCEE My Blog : http://stevemelan.wordpress.com

    Wednesday, April 4, 2012 6:13 AM