I've used the combinations shown in the table below:
|RDBMS||Driver||Typical JAR name||Typical Connection URL|
|Sybase ASE 15.7||net.sourceforge.jtds.jdbc.Driver||jtds-1.3.1.jar||jdbc:jtds:sybase://220.127.116.11:2545/axafusers|
|Sybase ASE 15.7||com.sybase.jdbc4.jdbc.SybDriver||jconn4.jar||jdbc:sybase:Tds:18.104.22.168:2545/axafusers|
As far as Sybase is concerned:
Regarding the possibility of using two different drivers for Sybase you may also refer to my axafusers-connectivity project for some performance tests. According to these tests it appears that the jTDS driver is more performant than the jConnect4.