IP Phone Setup

I need a bit of clarification on configuring the SIP accounts on my Linksys IP Phone. In short, I have an extension (say 110) configured on Asterisk. I want to be able to answer up to three concurrent calls to my extension on my IP phone. Can I configue three of the phnes SIP accounts to all use extension 110 credenitals (I guess essentially register it multiple times), or must I create additional extensions in asterisk (i.e, 111,112) and then configure each of my phones three four SIP accounts with one of the three extensions (L1=110, L2=111, L3=112) , then create a ring group that contains all three extensions as my inbound route. I am unsure as I am hearing different things on Asterisk’s ability to allow an extension to register multiple times.

You can not (technically you can but there will be issues) register a sip account more than once. If you are looking to be able to handle three calls at once on the phone then all you must do is have the phone register once. There is no default channel (concurrent call) limit on the asterisk side. Make sure you just set in the phone that “lines” 1-3 use sip account X.