# QSIG Conditions

- The MSDN/DPNSS features that contain the DPNSS features to which the QSIG features map must be enabled on all systems in the QSIG network in conjunction with the QSIG feature to ensure correct functionality.

- Requires a Universal NSU, PRI card (E1 supports ETSI and ISO, T1 supports ISO) or Embedded PRI.

- QSIG Callback is not supported on the PRI card.

- Before programming QSIG, check if the system at the other end of the QSIG link is set to QSIG Master or QSIG Slave and running the ISO protocol or the ETSI protocol. Set your system to the opposite Master/Slave condition and to the same protocol.

- Call forwarding, message waiting, call transfer, call offer, and path replacement are required for centralized voice mail and centralized attendant services.

- A uniform numbering plan must be in place throughout the networks that support QSIG.

- When using Call Deflection, the Forward softkey is supported. Users may not dial the digits instead.

- Call Offer with path retention is supported on transit and terminating nodes only.

- When centralized QSIG attendant/voice mail functionality is required, the systems hosting the attendants and/or voice mail should be upgraded first.

Related Topics

- QSIG Description

- QSIG Operation

- QSIG Programming