Converting SIP to TDM? We're looking to implement DID calling. Our local provider has indicated they can provide this via a SIP trunk, but cannot provide an E1. We also don't think they can provide an E1-over-SIP (where they convert a TDM signal to SIP on their end). For various unrelated (non-technical) reasons, we cannot connect a SIP trunk to our PBX, only an E1/T1. Question: Do solutions exist that would allow us to convert a straight SIP trunk to a TDM E1 for connection to our PBX? What are some examples? The PBX is a Meridian Option 11C, if that matters.

Yes, this is certainly possible. You can install a E1/PRI VWIC in a Cisco router and the Cisco router can act as a gateway between TDM and SIP. There are of course solutions by other vendors. This is a fairly broad subject, so you will need to read up on it, but it is defiantly possible.