When choosing between a CPI-C/LU 6.2 driver and a TCP/IP driver, consider the following factors:
Network type – SNA or TCP/IP
Network operating environment - Two or three-tier
If your current network is SNA-only or TCP/IP-only, choose the driver that supports your network protocol.
SNA networks have been running on IBM mainframes much longer than TCP/IP based-networks, and the SNA operational procedures are well established. However, if your LAN-side staff is not very familiar with SNA on a particular vendor platform, the SNA setup can be difficult.
TCP/IP is simpler to set up and maintain from the LAN, although it can be a challenge to get it running under MVS for the first time. In addition, TCP/IP on mainframes is a relatively new technology compared to SNA and as such, SNA is probably more robust and reliable.
TCP/IP performance appears to equal and in some cases exceed SNA-based performance. When going from the LAN to a mainframe, SNA requires a gateway, while TCP/IP does not.
Small, two-tier (gateway-less) Client Server networks are easier to set up and maintain than three-tier (gateway-enabled) networks, because three-tier networks have a gateway between the mainframe and the LAN. However, three-tier networks scale better, provide a single point of entry for security, and provide tracing facilities that can be easily enabled.
