IBM Corp’s Advanced Peer-to-Peer Networking announcements last month were a mixture of the unexpected and the disappointing. The disappointing bit was that yes, Advanced Peer-to-Peer Networking will appear on IBM mainframes, but no, not yet. Advance copies of VTAM version 4, which embodies the networking technology on MVS/ESA machines, are being handed out to some end users, but the rest of us will have to wait until sometime next year. The same delay holds true for RS/6000 users wanting to get hold of the improved APPN facilities offered by the promised enhanced AIX SNA Services/6000. Similarly, apart from four chosen partners, other companies will have to wait until the first quarter of next year before they see the APPN network node specifications, which the company has agreed to licence. The surprises? The TCP/IP networking protocol beloved of the Unix Community is now part of SAA, making it strategic. IBM had always said that it would switch from TCP/IP to whatever the International Standards Organisation finally mandated to tackle the problem in the Open Systems Interconnection model, but it begins to look as if TCP/IP is here to stay now. Such is the company’s desire to trumpet the theme of openness, that it now says that, despite its belief that APPN is the best bet for the networking future, it plans to support TCP/IP, Open Systems Interconnection, SNA-APPN, NetBIOS and IPX networking protocols transparently.
Common Semantics
In order to do this, it is imposing yet another layer between the network and application – Common Transport Semantics. Probably the biggest surprise though, is the news that in order to manage the peer-to-peer network, future versions of NetView the network management system that put the P into proprietary will be extended to include SNMP, CMIP and CMIS managers and agents, the former now acknowledged as the de facto industry standard, the latter two, the OSI equivalents. To be precise, IBM has committed itself to management systems based on the CCITT X700 series of recommendations, which encompass the Common Management Information Protocol and Common Management Information Services, as well as Simple Network Management Protocol. 3Com Corp, Novell Inc and Network Equipment Technologies Inc are the three companies chosen to get advance delivery of the APPN network node licence pack, consisting of 110,000 lines of code written in C, documentation and test cases. So why are they getting it early? To help test the code before its general release in the first quarter next year, according to IBM.
By Chris Rose
Coincidently, the delay in widespread availability means that developers will not get hold of the goods until around about the same time that IBM’s own 6611 router – based on the Rios RISC from the RS/6000 – will have APPN support added to it. The delay has irked Cisco Systems Inc for one – and the router company says that it will continue a two-pronged attack, negotiating with IBM for the OEM pack, but at the same time, persisting with its own reverse engineered implementation of the protocol, an implementation, moreover that it says will be better than the original. In particular, Cisco is critical of the multiple-hop approach inherent in APPN’s current approach. As it stands, the IBM protocol imposes a good deal of extra processing as a packet passes through each node, and the address header is recalculated at each step. Cisco says that it is working on that problem and IBM itself has recognised the hitch, saying that it will be fixed in APPN’s next incarnation, dubbed APPN+. IBM’s new networking blueprint suggests that the company is trying to be everything to everyman. Notable at the bottom layers is the company’s determination to support cell relay protocols, and a commitment to networks that will carry speech and video alongside data traffic. In wide area networks, IBM is talking about both Frame Relay and Asynchronous Transfer Mode protocols. For local area networks running to the desktop, it has committed to supporting the Fibre Channel Standard, running at Gigabit
speeds. Further up the layers there are more changes. Other network protocols now join APPN, nestling beneath IBM’s new Common Transport Semantics layer. Does this mean that applications will run equally well over TCP/IP or Open Systems Interconnection as they will over APPN, and that the company will spend as much time supporting these protocols? The Common Transport Semantics layer implies as much, but the truth is more likely to be that the foreign protocols will never be able to offer exactly the same functions as APPN in a true-blue IBM network. Topping off this lot is support for three types of application interface.
Berkeley Sockets
CPI-C, the Systems Application Architecture Common Programming Interface for Communications, will sit alongside remote procedure calls and message queueing, and IBM promises support for Berkeley Sockets – so that Unix applications using these hooks should run on the new VTAM subsystem. Novell is saying only that the protocol will appear in future versions of NetWare for SAA – the software designed to link the worlds of SNA and NetWare. Meanwhile, 3Com says that APPN code will appear in future versions of its Netbuilder bridge-routers and Linkbuilder hubs. Redwood City, California-based Network Equipment Technologies – which has been ascloseasthis to IBM for two or three years now, has pledged to incorporate the code into its IDNX local and wide area network exchange. The lure of the APPN licence is made explicit by Systems Strategies Inc, which specialises in selling SNA software to Unix vendors that want to link their systems to IBM’s. The New York-based company has just licensed the end node specs, and is negotiating now for the network node code. Why so? President Stan Adelman says that his OEM customers each want their machines to be at the heart of the network, and for that, they need APPN. Adelman is not saying how much he will have to pay for the privilege, but he believes that it will be very expensive.
