We have been using a Call Manager with Unity and now Unity Connection QSIG integration to Nortel PBXs for several years now. In preparation to upgrading to Call Manager 7.1.3bsu2 we upgraded our lab from 6.1.3b. All went well until we tested MWI functionality. SCCP phones work fine but the Nortel MWI does not. Downgraded back to 6.1.3b and all returned to normal.