The Simton IPX series now support DTMF and FSK caller id standards including Bellcore FSK (after the first ring), ETSI FSK after the first ring, British Telecom FSK (i.e. ETSI FSK with PR, before the first ring), ETSI DTMF after the first ring, and ETSI DTMF with PR (before the first ring). System administrator must find out (by testing) which call id standard that local telephone network is using before configuring the selection on the PSTN line in the Simton IPX management. Call id information is not only important for recipients to identify who is calling but also critical for the IPX system to authenticate the callers and to provide appropriate services and billing records.