Rochester Winds Down Non-TCP/IP Networking on the iSeries

by Timothy Prickett Morgan

For a decade, the handwriting has been on the wall. When the Ethernet adapter and the TCP/IP networking protocol became the undisputed foundation of the Internet and then the foundation for the corporate intranets that mimic the Internet at millions of companies around the world, we knew that alternative networking adapters and protocols were going to meet their end for the iSeries platform. And now, IBM has announced its sunset plan for non-TCP/IP networking--including twinax adapters.

But don't panic. This is not going to happen over night.

But, it is going to happen. Buried in the back of its announcements a few weeks ago, IBM put a "planning statement" in the documents that explained what it was up to. This statement, said IBM, was intended to give iSeries shops insights into the directions the iSeries hardware and software engineers plan to take the platform--or in this case, more accurately, the directions they do not plan to take the platform. And, in perfect legalese, this statement also pointed out that IBM's position is subject to withdrawal or change without any notice.

Just to make sure there is no confusion about precisely what IBM said, here's the planning statement:

The i5/OS operating system has long-term support and development plans for many key industry WAN and LAN protocols. These include TCP/IP, PPP, Async, Bisync, Ethernet, and APPN via Enterprise Extender. i5/OS has both short-term and mid-term support plans for SDLC, SNA, X.25, and Frame Relay. IBM plans to continue providing i5/OS support for SDLC, SNA, X.25, and Frame Relay in V5R3 and in the release after V5R3. IBM recommends that you start moving off these protocols before IBM's eventual withdrawal of support. i5/OS releases introduced after mid-2007 may not include support for these protocols.

Though i5/OS V5R3 and the following release will continue to support SDLC, SNA, X.25, and Frame Relay protocols, new hardware WAN and LAN adapters announced starting in 2005 will not support these protocols. You may need to obtain either OEM protocol converters or earlier generation IBM WAN and LAN adapters, if these protocols are important to you to purchase new WAN and LAN adapters from IBM that would allow you to attach 5250 remote controllers such as a 5294, 5394, and 5494, which use the SDLC or X.25 protocol.

The i5/OS operating system will continue to support twinaxial controllers, but IBM plans to withdraw from marketing the sale of new twinaxial controllers in mid-2006. IBM recommends that new workstations and printers be attached via LAN or WAN and not via twinaxial workstation controllers. Attachment of existing twinaxial devices will be available through existing IBM twinaxial controllers, OEM protocol converters, or replaced by LAN-attached technology. There should be no impact to application programs using the 5250 datastream.

i5/OS will continue to support Token Ring network (TRN) adapters, but IBM plans to withdraw from marketing the sale of new TRN adapters in mid-2006. IBM recommends that you move from TRN to Ethernet, which has become an industry standard.

Additional information may be found on the iSeries Planning Information Web site statements of direction, and products no longer supported on a release, with mitigation plans, as available. Click on www-1.ibm.com/servers/eserver/iseries/support/planning/nav.html.

For old-time System/3X and AS/400 shops, the above statements probably read a bit like heresy. The AS/400 without twinax adapters? No more Token Ring? No more APPN?

The truth is a lot sadder than this, of course. To IBM's great credit, the Systems Network Architecture and its related communication protocols were, in many ways, vastly superior to TCP/IP; Token Ring was similarly a higher-bandwidth, more-secure networking scheme for many years (until IBM stopped investing in it more than a decade ago); and the Advanced Peer to Peer Networking extensions did sophisticated peer-to-peer computing before Napster made it cool (or rather, uncool in terms of its legality, cool in terms of its technology). SNA was launched in 1974, but in 1982, SNA was tweaked to add peer-to-peer computing because midrange systems had proliferated at that point and companies were building local area networks and wide area networks (or WANs, which connect multiple geographic sites together using special telecom links). The APPN extensions did the routing work that IP routers from Cisco Systems and others later did and which led to the Internet and most corporate networks. Somewhere, out there in an alternative universe, if someone at IBM had figured out in the early 1980s to open source SNA, the company would have spawned a whole slew of router manufacturers (as well as its own gear) and the Internet would have exploded a decade earlier. (I am not certain if that would be a good thing or a bad thing.)

Back in the bronze age, when I was cutting my teeth on midrange servers, I learned about SNA and APPN, and its related Advanced Peer to Peer Communications (APPC) protocol for bringing the PC and workstations into SNA networks. I was very impressed by these technologies. But the Ethernet spec took off and the TCP/IP protocol was adopted by the Internet because it was in the public domain. Had IBM taken SNA open source (who would have thought of it back in the late 1970s or at any time in the 1980s?) and allowed broad licensing of Token Ring technology, we might be looking at a much smarter Internet than we currently have. Such is always the way with hindsight.

By the way, it is not just IBM that is facing the music on SNA. AT&T, which bought IBM's Global Network for $5 billion back in December 1998, has already announced that its SNA Leased Line Services, SNA Leased Line Network Services, SNA Dial, Connectivity Services, Enhanced Network Services, AS/400 Connection Service, and X.25 networking will be discontinued on June 1 in the Canada, Asia/Pacific, Latin America, and Japan regions of its network. On December 31, AT&T's Managed Data Network Services components for SNA in the United States--specifically its SNA Leased Line and SNA Dial Services--will have its service turned off.