TOC is the recommended protocol, because gaim still has some problems using Oscar. However, Oscar is usable (I use it myself most of the time). If you find you can't sign on with TOC, you can try to sign on using Oscar until the TOC server is back online.
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What is the recommended protocol to use? Oscor or TOC? Sometimes one logs in while the other won't.
TOC is the recommended protocol, because gaim still has some problems using Oscar. However, Oscar is usable (I use it myself most of the time). If you find you can't sign on with TOC, you can try to sign on using Oscar until the TOC server is back online.