Elastix install between telco PRI and Nortel MICS

I will be installing an Elastix server with a Sangoma A104, without hardware echo cancelation, between a single incoming PRI and an existing Nortel MICS. The Elastix server will have a PRI coming in from the telco and a T1 crossover cable connecting it to the Nortel. The Nortel config will be provided. I will install Elastix 2.0.3, SSH access, and Sangoma drivers. I need Elastix configured to record and pass all calls between the Nortel and the telco. Specificly, in the event of elastix going down, being able to bypass Elastix by plugging the incoming PRI directly into the Nortel without reconfiguring the Nortel.