Is there a 64-Bit Version of IBM Communications Server for Windows?
There is no 64-Bit Version of IBM Communications Server for Windows. The SNA API client can connect to a CS Windows 32-bit server only.
Resolving the problem
The strategy for the Windows platform with the distributed Communications Server product is the following:
The Communications Server for Windows and the Personal Communications for Windows products provide a full SNA stack on 32-bit operating systems. These products will continue to be supported for some time. For Windows 64-bit operating systems, the strategy is to replace the SNA API libraries supported by CS Windows and PCOMM with the IBM Remote API client for Windows that are part of the Communications Server for Data Center Deployment v7 product.
The Remote API client provides several advantages over the CS Windows implementation in the branches:
1) The Remote API client for Windows replaces the SNA API libraries such that applications using APPC, CPI-C, LUA will not need to be changed in most implementations. The Remote API client provides 32-bit and 64-bit APIs, so legacy and new applications can use either method for their SNA connectivity.
2) The Remote API client is a thin TCP/IP client that connects SNA verbs over any IP router to a domain of servers (think of this as a cloud) that issues the SNA verbs on the clients behalf. These servers are located in the data centers very close or inside the mainframe (depending on the platform, Linux, Linux on System z or AIX).
3) There is backup and redundancy provided in the design so that a client is not locked into one server, but has access to up to nine servers in a domain. This implementation is like a cloud. The client does not connect to a server, but to a domain of servers.
4) The total cost of management is very small compared to any current full stack implementation. Licensing the Remote API Client/server is less than a full SNA stack via CS Windows. Cost to maintain a Remote API client is much less than a full SNA stack. Most of the time, there are several hundred parameters per CS Windows server. The Remote API requires a maximum of three to four parameters to be connected. All the SNA resources move to the data center near the mainframe, where it requires less SNA expertise in the remote branches and provides a small number of servers to manage.
5) Scalability: The Remote API clients uses only one or two TCP/IP sessions for all the SNA over IP connectivity to the domain. The CS Windows SNA connectivity uses five UDP ports per link using Enterprise Extender. The SNA full stack implementation uses a minimum of five RTP sessions for overhead before the SNA application session is used, per server. So, with 600 branches, this will save around 3000 RTP sessions that the VTAM on the host does not need to manage.
There are a growing number of implementations using the Remote API Client for Windows 64-bit clients. The range for size of implementations of the Remote API Client is from a few hundred to some with 1500, 3000 and 4000 branches.