An anonymous user writes:
More than 10 years ago, we had a beautiful fully APPN-enabled SNA network that consisted of two central AS/400s (one production, one backup) and 5494 controllers connected through Motorola modems (routers did not exist yet) and a Motorola concentrator that was connected to the two AS/400s via three V35 lines.
One day, I saw that one 5494 controller gave no sign on the production iSeries. I promptly contacted the local responsible in order to find out what the situation was. I told him I saw that he had a problem, and his site was not working on our production system. He told me they were.
After a lengthy yes-no discussion, I learned one of the advantages of APPN: indeed, they were working on the production system, but not through their normal connection, but via the backup system and the Token Ring that connected this backup system with the production system.Where do you want to go next?