We've just set up a Revolabs conference phone as a SIP endpoint an a customer's UC520 using the guide from Revolabs.  We've added the following config:-

voice register global
mode cme
source-address 10.1.1.1 port 5060
max-dn 1
max-pool 1
!
voice register dn 1
number 739
no-reg
!
voice register pool 1
id mac 1111.1111.1111
number 1 dn 1
dtmf-relay rtp-nte
username 739 password ext739
codec g711ulaw
no vad

The handset registers fine with the system and gets extension 739.  We can dial out fine as well, but when we try and dial in using the DID defined it just waits for a while and then says busy.  We also can't call from another extension to the handset - the call just times out.

What do we need to add to enable inbound calls to the phone?  Not sure if some sort of SCCP to SIP command is needed but can't find anything useful.

Thanks