[Twisted-Python] MSN IM question: two factories, one reactor?

I want to write a chat bot that signs into MSN IM, then waits passively for users to send it messages. When the bot gets a message, it should just reply back to the sender. Here's where I'm struggling: it appears that I need to maintain a connection to a notification server AND a switchboard server. How to do this with only one reactor running? I'm new to twisted. TIA Matt