E-1 inbound call times out if no ANI delivered

[4946]

IPO 500
SW 4.2.20
E-1 Configured for:
R2 signalling
Four digits of DID
Ten Digits of ANI
Channels set up for Incoming Any Bearer R2DID MFC Dialing

Everything works inbound for domestic calls (local and LD).
International inbound calls have no ANI from carrier and time out. The 4 digits of DID are delivered correctly and the IPO 500 appears to wait indefinitely for the ANI delivery which never comes. Is there any timer that can be shortened for the ANI delivery, so the switch can process the call with just the DID information? (The ANI information is not currently used for routing)

Thanks for your observations and ideas.