As was noticed in About FIX 5.0 chapter, when FIX 5.0 was released, the decision was made to separate application-level protocol specifications and transport-level part of the specifications.
As the result, FIXT 1.1 (the FIX Session Protocol version 1.1) became available.
In order to differentiate between them, there is a special overload of FixEngineCreateSession(String, String, FixVersion, SessionExtraParameters, MessageStorageType, FixVersion) function that accepts 2 different parameters of com.b2bits.FIXAntennaFixVersion type.
First parameter version is a version of application-level FIX protocol while ssnver is a transport-level protocol.
The table below explains what possible combination of version and ssnver parameters will be valid. version = FIXT11 is not valid because FIXT11 is a session-level protocol.
|FixVersion||version = FIXT11||version = FIX50||version = FIX44 .. FIX40|
|ssnver = FIXT11||Invalid||Valid||Valid|
|ssnver = FIX50||Invalid||Valid||Invalid|
|ssnver = FIX44 .. FIX40||Invalid||Invalid||Valid, if ssnver matches version|