Suggested alias is supposed to be a shorthand for your channel, so for example a pear package can be installed via pear install pear/HTTP_Session2 (assuming PEAR is not your default channel).

In your channel.xml, the suggested alias is "pear.phpdoctrine.org", I'd propose changing it to "doctrine" instead. This would allow people to run:

pear channel-discover pear.phpdoctrine.org
pear install doctrine/Doctrine