384 3Com® VCX V7111 VoIP Gateway User Guide Frequency response in transmit and receive direction Hook thresholds Ringing generation and detection parametersThis means, for example, that changing impedance matching or hybrid balance does notrequire hardware modifications, so that a single device is able to meet requirements fordifferent markets. The digital design of the filters and gain stages also ensures highreliability, no drifts (over temperature or time) and simple variations between different linetypes.In future software releases, it is to be expanded to consist of different sets of lineparameters, which can be selected in the ini file, for each port.Use the parameter CountryCoefficients (described Table 47) to configure the FXOcoefficients.User Information FileThe User Information file maps PBX extensions (connected to the V7111 gateway) to globalIP phone numbers (alphanumerical). In this context, a global IP number serves as a routingidentifier for calls in the IP World. The PBX extension uses this mapping to emulate thebehavior of an IP phone. Note that the mapping mechanism is disabled by default and mustbe activated by using the parameter EnableUserInfoUsage (described in GeneralParameters).Each line in the file represents a mapping rule of a single PBX extension (up to 100 rules canbe configured). Each line includes five items separated with commas. The items aredescribed in Table 100. An example of a User Information file is shown in Figure 144.Each PBX extension registers separately (a REGISTER message is sent for each entry, onlyif AuthenticationMode is set to Per Endpoint) using the IP number in the From / To headers.The REGISTER messages are sent gradually (that is, initially, the gateway sends requestsaccording to the maximum number of allowed SIP dialogs (configured by the parameterNumberOfActiveDialogs), after each received response, the subsequent request is sent).Therefore, no more than NumberOfActiveDialogs dialogs are active simultaneously. Theusername and password are used for SIP Authentication when required.The calling number of outgoing Tel to IP calls is first translated to an IP number and then (ifdefined) the manipulation rules are performed. The Display Name is used in the Fromheader in addition to the IP number.The called number of incoming IP to Tel calls is translated to a PBX extension only aftermanipulation rules (if defined) are performed.The User Information file is a text file (the file size must not exceed 10,800 bytes) that can beloaded using the ini file (UserInfoFileName, described in Table 78), the Embedded WebServer (see Auxiliary Files) or by using the automatic update mechanism (UserInfoFileURL,see Automatic Update Mechanism).
