Talk:Systems Network Architecture

message: From the article:
:The first numbers of your credit card is usually a SNA routing sequence.
Really? Can we have a cite for this?  — Preceding unsigned comment added by The Anome (talk • contribs) 01:47, 4 September 2002‎
:On a SNA based VISANET  Take a TranScan a PC-based intelligent protocol monitor and analyzer designed to support Credit Card, Debit Card, Bank Card and Financial Transaction Processors press B to show message routing and usually it is your credit card number
:ASKJVA — Preceding unsigned comment added by Askjva (talk • contribs) 04:07, 5 November 2002 (UTC (UTC)
::Possibly for some definition of message routing routing that has nothing to do with SNA, but routing in an SNA network is controlled by identifying the sending and receiving logical units, not with a routing sequence. Routing decisions are made by consulting tables in intermediate nodes. Try a protocol analyzer that breaks out the header fields in the SNA Request/Response (RR) units rather than presenting the financial data. Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:24, 17 October 2011 (UTC)
replies: text: A basic feature of SNA is providing a transparent end-to-end communications channel that makes the application independent from the implementation of the networking infrastructure. In the Internet era this seems utterly obvious, but in the communication "systems" of the 1960s it was not. SNA takes care of network routing, applications may implement specific application routing.    — Preceding unsigned comment added by Rbakels (talk • contribs) 09:28, 14 March 2014 (UTC)
thread_title:  Credit card numbers begin with an SNA routing sequence? 

message: I decided not to make Network Control Program a wiki link. Problem is that existing article describes the ARPANET NCP and says nothing about IBM's use of the same term in SNA.Rdmoore6 19:41, 18 January 2006 (UTC)
replies: text: Linked to IBM Network Control Program. Philcha 16:09, 19 October 2007 (UTC)
thread_title: Network Control Program

message: The LU type pertains to an LU-LU session, not the actual LU. As an expample, it was common for the same printer to be in an LU1 session with one application and an LU3 session with a different application. Shmuel (Seymour J.) Metz Username:Chatul (talk) 22:40, 16 November 2010 (UTC)
thread_title:  LU type pertains to session, not to terminal 

message: The ability to share a communications line between applications goes all the way back to QTAM. The ability to share a line between TSO and another application is as old as TSO; it started with TCAM. Shmuel (Seymour J.) Metz Username:Chatul (talk) 22:53, 20 November 2010 (UTC)
thread_title:  Line sharing prior to SNA 

message: The IBM System/360 and System/370 did not act as controllers for peripherals and were not limited to 16 I/O devices per channel. An I/O channel connected to control units, which in turn connected to peripheralsIn some cases the control unit was integrated with the peripheral.. In the case of DASD, tape and telecommunications, it was normal for one controller to connect to or include multiple peripherals.
 Shmuel (Seymour J.) Metz Username:Chatul (talk) 23:05, 20 November 2010 (UTC)
thread_title:  S/360 and S/370 I/O 

message: SDLC and HDLC did not use an ECC; they used a simple Cyclic redundancy check (CRC). Shmuel (Seymour J.) Metz Username:Chatul (talk) 23:16, 20 November 2010 (UTC)
replies: text: And what if, as I think is the case in most if not all uses of SDLC/HDLC (including SDLC in SNA), you don't have a known, fixed, frame length? Guy Harris (talk) 12:04, 15 December 2020 (UTC)
thread_title:  Error checking in SDLC and HDLC 

message: While IBM initially only supported SNA in VTAM, they later added SNA support to TCAM 10. Also, as part of the Advanced Communications Function (ACF) announcement they added Multi-System Network Facility (MSNF) to ACF/TCAM and ACF/VTAM. MSNF, APPN and MSI each altered the way routing was done in SNA. In particular, MSNF supported connecting two mainframes with a channel-to-channel adapter (CTCA), but communication line interconnection (remote) was also supported).
Also, should I add any of the relevant manuals to the article? Some are brief summaries and some are highly technical.  Shmuel (Seymour J.) Metz Username:Chatul (talk) 15:55, 17 October 2011 (UTC)
thread_title:  History of SNA 

message: To answer the question of whether the 3770 is related to the 2780 and 3780, no, it is not. However, there is no separate article on the 3770 and the 2780 article does discuss it, so the link to that article is appropriate unless and until somebody splits the 3770 off into a separate article. Shmuel (Seymour J.) Metz Username:Chatul (talk) 12:47, 27 June 2012 (UTC)
replies: text: Unfortunately there isn't much 3770 info online (yet).  Hopefully there'll be more in a while. Peter Flass (talk) 14:02, 27 June 2012 (UTC)
replies: text:  www.3770-emulation.com/‎ or en.wikipedia.org/wiki/IBM_2780/3780‎ Shjacks45 (talk) 09:46, 27 June 2013 (UTC)

text: Introduction to IBM 3770 SNA/RJE Communications does give some details, although the reference to emulation is incorrect. However, IBM 2780/3780‎  is the article about which the question was originally asked. Shmuel (Seymour J.) Metz Username:Chatul (talk) 17:32, 27 June 2013 (UTC)
thread_title:  Status of 3770 

message: I added some references to the article, but did not cite the manuals for protocol details/ Would those be TMI, or is it reasonable to add them as well? E.g.,
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Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:40, 17 July 2013 (UTC)
replies: text: I'd say that if the article gives those protocol details, it's appropriate to give citations for those details. Guy Harris (talk) 21:24, 17 July 2013 (UTC)
replies: text: The article currently does not give those details. Shmuel (Seymour J.) Metz Username:Chatul (talk) 18:58, 19 July 2013 (UTC)
replies: text: Then they wouldn't be references.  They might, however, be worth including in "External links" or "Further details" or something such as that. Guy Harris (talk) 21:38, 19 July 2013 (UTC)
thread_title:  References for protocol details? 

message: The article associates "Advanced Communication Function" with SNA. That is not correct. There was SNA before ACF.
Initially, the mainframe SNA software was called just VTAM, and it was delivered free of charge with the operating system software, like all IBM systems software at the time. The reason was that IBM software ran only on IBM hardware, so the price was effectively included in the hardware price.
With the advent of "plug compatible" computers, computers made by other manufacturers such as Amdahl that ran IBM software, there was a reason to charge systems software separately. The first systems software packages charged separately were VTAM and NCP, now called ACF/VTAM and ACF/NCP. Only later, complete operating systems were charged, like MVS and VSE.
ACF/VTAM was announced in 1976 and shipped in 1978. 
Rbakels (talk) 11:35, 15 December 2020 (UTC)
thread_title:  "Advanced Communication Function" 

message: The article covers network addressable units, e.g., SSCP, but it does not discuss, e.g., the structure and types of packets, the types of data flow, the mechanics of initiating and terminating sessions. --Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:45, 13 December 2021 (UTC)
thread_title:  Protocol elements