QSIG is an ETSI standard for an ISDN protocol used for interconnecting PBXs. It allows features that normally only work on a single PBX (camp on, call back, etc.) to work seamlessly across a network of PBXs. These networks are sometimes called a: Private Integrated Services Network or PISN.

See Also

• QSIG Wikipedia Article
• ETSI - European Telecommunications Standards Institute
• qsig.info - Information Website about QSIG and PBX interconnections
• QSIG Support in chan_capi