If this appears twice blame the lamentatble - did I say lamentable - performanbce of the list service!
- John > ... CTC; to implement VTAM cross domain ... I *think* I understand what you are saying here but in case it is not clear to *all* subscribers, it might be worth emphasising that there is a. one flavour of the implementation of channel-to-channel (CTC) connections which works *only* with VTAMs presenting the appearance of Type 5 nodes to each other b. another flavour of the implementation of CTC connections which works *only* with VTAMs presenting the appearance of Type 2.1 nodes to each other OK, so what does this mean? - VTAM presenting the appearance of a type 5 node operates SNA subarea protocols. - VTAM presenting the appearance of a type 2.1 node operates, in principle, "Low Entry Networking" (LEN) or APPN protocols, which are an extension of LEN protocols; APPN protocols formally incorporate LEN protocols. In fact, for a reason having everything to do with "marketing" and nothing whatsoever technical, VTAM does *not* implement LEN protocols over the "type 2.1 CTC", only APPN protocols. I believe your "cross domain" is intended to indicate traditional subarea SNA. In this you are strictly incorrect since you just may not know sufficient about type 2.1 nodes to know that each type 2.1 node is its own domain just as type 5 nodes in subarea SNA. Thus sessions running between type 2.1 nodes are also "cross-domain". If you want to know more, just examine all available operands of the VTAM CDRSC (cross-domain resource) statement.[1] So, assuming my interpretation is correct, ESCON can be used in order to implement the "type 5 CTC" but FICON cannot. I checked that FICON can be used to implement the "type 2.1 CTC" - let's acknowledge the artificial restriction imposed by IBM in their wisdom and call it the "APPN CTC" - because I assisted in a "network" redesign at a customer a few years ago oriented to a complete conversion of a mixed APPN and subarea SNA network - which worked as a Curate's egg - to a pure APPN network - which worked as an egg fresh from the coop. The design required the definition of a number of CTC connections for use by the APPN network. Disturbing a lot of dust I found some customer documents onto which I happened to have hung labelled "FICON CTCs". - [1] http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/F1A1B6C0/2.4 - Chris Mason --- John > ... CTC; to implement VTAM cross domain ... I *think* I understand what you are saying here but in case it is not clear to *all* subscribers, it might be worth emphasising that there is a. one flavour of the implementation of channel-to-channel (CTC) connections which works *only* with VTAMs presenting the appearance of Type 5 nodes to each other b. another flavour of the implementation of CTC connections which works *only* with VTAMs presenting the appearance of Type 2.1 nodes to each other OK, so what does this mean? - VTAM presenting the appearance of a type 5 node operates SNA subarea protocols. - VTAM presenting the appearance of a type 2.1 node operates, in principle, "Low Entry Networking" (LEN) or APPN protocols, which are an extension of LEN protocols; APPN protocols formally incorporate LEN protocols. In fact, for a reason having everything to do with "marketing" and nothing whatsoever technical, VTAM does *not* implement LEN protocols over the "type 2.1 CTC", only APPN protocols. I believe your "cross domain" is intended to indicate traditional subarea SNA. In this you are strictly incorrect since you just may not know sufficient about type 2.1 nodes to know that each type 2.1 node is its own domain just as type 5 nodes in subarea SNA. Thus sessions running between type 2.1 nodes are also "cross-domain". If you want to know more, just examine all available operands of the VTAM CDRSC (cross-domain resource) statement.[1] So, assuming my interpretation is correct, ESCON can be used in order to implement the "type 5 CTC" but FICON cannot. I checked that FICON can be used to implement the "type 2.1 CTC" - let's acknowledge the artificial restriction imposed by IBM in their wisdom and call it the "APPN CTC" - because I assisted in a "network" redesign at a customer a few years ago oriented to a complete conversion of a mixed APPN and subarea SNA network - which worked as a Curate's egg - to a pure APPN network - which worked as an egg fresh from the coop. The design required the definition of a number of CTC connections for use by the APPN network. Disturbing a lot of dust I found some customer documents onto which I happened to have hung labelled "FICON CTCs". - [1] http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/F1A1B6C0/2.4 - Chris Mason On Fri, 10 Aug 2012 13:22:59 -0500, McKown, John <[email protected]> wrote: >We are more likely to eliminate the z than upgrade it. But, we do use some >ESCON. We use them for: CTC; to implement VTAM cross domain and XCF >communications for *basic* sysplex; 3490 external tape drive, for external use >(very rare); Visara/local 3270 controller for z/OS consoles. > >-- >John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
