Server classes and ASTC

Internally, ASTC views a server as one of three types:

These types map to the three sets of callbacks used, and map to server classes as indicated in Table 2-5:

**Table 2-5: Transaction capabilities**
ASTC server type	Component Integration Services server class
DTM-enabled	ASEnterprise (12.x or greater) DC/Oracle 12.5
Pre-DTM	ASEnterprise (pre-12.0) ASAnywhere ASIQ other Direct Connect sds
No-DTM	db2

Before starting a distributed transaction, the local server must be named. @@servername cannot be null.