This is on incoming calls. No special configuration on either end. CallCntric provided this detail:
your Obi110 is specifically rejecting our test call with a "486 Busy Here" status. The following is the exact packet we're receiving back from your Obi110:
SIP/2.0 486 Busy Here
Call-ID:
9598499-3732104345-757406@msw1.telengy.net CSeq: 1 INVITE
Content-Length: 0
From: "Callcentric Who" <sip:12123794000@66.193.176.35>;tag=3732104345-757435
To: <sip:1**********@ss.callcentric.com>;tag=SP111214b514e8a77b
Via: SIP/2.0/UDP 204.11.192.38:5080;branch=z9hG4bK-c4ab4dc6c6da7654ee9298ee1bc8cb4d;change=ta;received=204.11.192.38;rport=5080
Server: OBIHAI/OBi110-1.3.0.2886