setting up to access remote Oracle

I hope this isn't too a dumb of a question, but it's been years since I last had to do this and Google isn't helping much.

I have Oracle 9i installed on one server and am running sqlplus on another. If I type "sqlplus user_at_SID" it works, but I'd like to be able to drop the @SID part. I have a vague, quite possibly incorrect memory that if you have ORACLE_SID set (which I do) SQL*Net will use it when the local connect fails, but I haven't been able to get it to work.

Is it possible to do this, and if so, can anyone provide an example?

Thanks,

janine

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