 again appending the extension in order to turn the message lamp off. I've config- ured CUE to dial 8000 to enable the lamps and 8001 to disable the lamps. We'll talk more about pattern matching in "Dial Peers" on page 551, but for now, understand that a period in a number string means match any number: R1-PBX(config)#ephone-dn 40 R1-PBX(config-ephone-dn)#number 8000 R1-PBX(config-ephone-dn)#mwi on And here's the matching ephone-DN needed to turn the lamps off: R1-PBX(config)#ephone-dn 41 R1-PBX(config-ephone-dn)#number 8001 R1-PBX(config-ephone-dn)#mwi off One of the fun ways to test this is to actually dial the number. Go to a phone, pick up the handset, and dial 8000xxx, where XXX is the extension of your phone. The light should come on. Dial 8001xxx, and it will turn back off. I absolutely don't recommend dialing your friend's MWI-on code at work, thus making him think he has a message when he has none. The confusion and frustration he will experience after days of his light mys- teriously going on when there are no messages waiting is not funny at all. Seriously-don't do that. Chapter 30: VolP This, by the way, is why I didn't number the extension for the outside line as the full 10-digit phone number. If I had, MWI would have required more complex dial peers or possibly variable-length dial peers. Dial Peers Dial peers seem to confuse a lot of people when they first encounter them. Logical thought is required to make them elegantly simple, which consumes time that a lot of engineers don't think they have. I've seen some horrendously complicated dial peers, numbering in the hundreds, that, after careful thought, we consolidated into fewer than 10. Think of dial peers like static routes-the more you can aggregate them, the happier you'll be. Dial peers are another VoIP feature that's almost infinitely configurable. There are many ways to accomplish the same goal, SO if you don't like the ones I've listed here, or can think of a better way to write them, by all means, give it a try. There are many types of dia