Quadro "All In One Box" solutions connect your office, the local PSTN and the Internet into a single voice network. Phones in the local PSTN connect to the QuadroCS through any Quadro IP telephony product.

Phones in the local PSTN (analog or digital) also connect to the QuadroCS through an Internet Telephone Service Provider (ITSP).

Any phone in the local PSTN may be called from a QuadroCS through an ITSP or through a Quadro SIP router.

Any SIP phone is call compatible with the QuadroCS.

Legacy PBX's use an IP gateway such as the Quadro E1/T1 to reach the QuadroCS.