1.1 Information about IP Telephony ServiceThe Virtual 16-Channel SIP CO Line Card (V-SIPGW16) is a virtual CO line card which is designed to be easilyintegrated into an Internet Telephony Service provided by an ITSP (Internet Telephony Service Provider).As a major SIP Provider, an ITSP provides its telephony service partly through the conventional telephonenetwork (e.g., ISDN and Mobile), which is fee-based. An ISP (Internet Service Provider), another major SIPProvider, does not provide telephone connection itself. However, providing its users with Internet access, anISP provides voice communication on the Internet for free. In this way, with VoIP technology based on the SIPprotocol, the cost of voice communication can be much cheaper than conventional telephone networks. Amaximum of four V-SIPGW16 cards can be installed to the virtual CO line slots of the PBX. The channelcapacity of the card allows users to connect to up to 32 different ISP/ITSPs.V-SIPGW16 Connection OutlineThe following diagram illustrates a simple VoIP network connecting the V-SIPGW16 card to the Internet.PBX withV-SIPGW16 CardPCLAN(Local Area Network)WAN (Wide Area Network)InternetLocalTelephoneIP-PTISPITSPRouterSwitchingHubRequirements for Internet Telephony Service• You need to subscribe with an ISP for Internet connection.• You need to subscribe with an ITSP for telephone connection. The ISP and ITSP may be part of the samecompany.Note• VoIP communication using the V-SIPGW16 card may deteriorate depending on the ITSP being used.6 Programming Manual for Virtual SIP CO Line Card Document Version 2011-101.1 Information about IP Telephony Service