Open ClientConnect supports both three-tier (gateway-enabled) and two-tier (gateway-less) environments. When installing and using Open ClientConnect, follow the instructions in this book that are specific to your environment.
If you use SNA as your protocol, you must use a three-tier environment for routing.
The DirectConnect product no longer comes with an MCC
for TCP. A three-tier (gateway-enabled) environment using TCP as
your protocol is no longer an option.
If you have standardized to TCP for connectivity from CICS to Adaptive Server Enterprise, you must use the two-tier environment for routing. The two-tier environment allows Open ClientConnect to directly login to an Adaptive Server Enterprise, which eliminates the need for an MCC gateway.
An Open ClientConnect network configuration using two-tier (gatewayless) processing consists of the following:
A host-based client, which is an Open ClientConnect program running under CICS. The client program selects a server and sends requests to that server.
A server, which can be any server that Open ClientConnect applications can access, including servers on the LAN—Sybase Open Servers and Adaptive Server Enterprises—as well as Open ServerConnect running in a separate CICS region. If TCP is the protocol, Open ClientConnect can access servers running in the same CICS region.
