listener does not currently know of SID given in connect descriptor in oracle 10g and solaris 10 env
There are a few problems.


 given the fact that you specified local_listener, you want your database instance to register to a non default listener for which the tnsalias should be LISTENER_OTRS
 the tnsalias LISTENER_OTRS is missing
 the tnsalias otrs is misformed (it has multiple addresses but not the ADDRESS_LIST parameter (in this case, the last piece will be ignored))


fix: remove the local_listener parameter and your instance will register perfectly fine on the listener that sits on port 1521 (the default port). The instance will register during startup or, if the listener is started later, once every few minutes or after issuing 'alter system register;'.

If you did this, lsnrctl status will show the instance name.
Also: don't forget that on *nix, the ORACLE_SID is case sensitive.

The otrs tnsalias could be used to connect to the instance, once it has registered itself to the listener. You can test this using 'tnsping otrs'