How to Enable SNA Server IPX/SPX Clients to Use SPXII

MORE INFORMATION

An improved version of SPX is SPXII. SPXII has the following advantages:

• SPXII can use the maximum packet size allowable by the network type. On an Ethernet LAN, for example, an SPX II packet can be a full 1518 bytes. Standard SPX is only capable of sending 576 byte packets.
• SPXII can use "windowing" where multiple packets can be outstanding at one time. It uses negative acknowledgments (NAKs) to indicate that some packets were not received. Standard SPX allows only one packet to be outstanding at any time.

To enable the newer SPXII protocol to work with SNA Server, add the following subkey to the registry:

   \Hkey_Local_machine
     \System
       \CurrentControlSet
         \Services
           \SnaBase
             \Parameters
                \SnaSpx
				

Then, add the following value:

   SPXII:REG_SZ:yes
				

SPXII has been supported since SNA Server 2.1 with the addition of the registry entry, but only on Windows NT 3.5/3.51, not on Windows NT 3.1.

Client support is as follows:

• Windows 95: Enable the same registry entry as above.
• Windows NT: Enable the same registry entry as above.
• Windows 3.x and MS-DOS: SPX-II is not Supported on these platforms.