That would also be an option... I remember connecting an IPX800 to a Siemens system. Even though Siemens said they were QSIG compliant, we still had issues. Siemens uses QSIG for video conferencing and added extra hex coding to run Video. Needless to say, after finding this out, we asked Siemens if they could strip the extra coding out, they said yes but told us that if they did that, it wouldn't be industry standard QSIG and would be considered Custom Qsig. go figure...