Имя сервера SIP По умолчанию $ VERSION для жесткого телефона Cisco SPA 942

При чтении прекрасного руководства для IP-телефона Cisco SPA 942 под маркой Linksys:

что, в частности, означает:

SIP Server Name Server header used in responses to inbound responses. Defaults to $VERSION. 

$VERSION такое переменная?

Из руководства:

Firmware Version 5.1Chapter 5 Linksys IP Phone Field Reference SIP Tab SIP Tab This section describes the fields for the following headings on the SIP tab: • SIP Parameters, page 5-9 • SIP Timer Values (sec), page 5-11 • Response Status Code Handling, page 5-13 • RTP Parameters, page 5-13 • SDP Payload Types, page 5-14 • NAT Support Parameters, page 5-16 • Linksys Key System Parameters, page 5-17 SIP Parameters Note None of the following parameters apply to the SPA901. Field Description Max Forward SIP Max Forward value, which can range from 1 to 255. Defaults to 70. Max Redirection Number of times an invite can be redirected to avoid an infinite loop. Defaults to 5. Max Auth Maximum number of times (from 0 to 255) a request may be challenged. Defaults to 2. SIP User Agent Name Used in outbound REGISTER requests. Defaults to $VERSION. If empty, the header is not included. Macro expansion of $A to $D corresponding to GPP_A to GPP_D allowed. SIP Server Name Server header used in responses to inbound responses. Defaults to $VERSION. SIP Reg User Agent Name User-Agent name to be used in a REGISTER request. If this is not specified, the <SIP User Agent Name> is also used for the REGISTER request. Defaults to blank. SIP Accept Language Accept-Language header used. To access, click the SIP tab, and fill in the SIP Accept Language field. There is no default (this indicates Linksys IP phone does not include this header). If empty, the header is not included. DTMF Relay MIME Type MIME Type used in a SIP INFO message to signal a DTMF event. This field must match that of the Service Provider. Defaults to application/dtmf-relay. Linksys IP Phone Administrator Guide Firmware Version 5.1 5-9Chapter 5 Linksys IP Phone Field Reference SIP Tab Field Description Remove Last Reg Lets you remove the last registration before registering a new one if the value is different. Select yes or no from the drop-down menu. Defaults to no. Use Compact Header Lets you use compact SIP headers in outbound SIP messages. Select yes or no from the drop-down menu. If set to yes, the Linksys IP phone uses compact SIP headers in outbound SIP messages. If set to no, the Linksys IP phone uses normal SIP headers. If inbound SIP requests contain compact headers, Linksys IP phone reuses the same compact headers when generating the response regardless the settings of the <Use Compact Header> parameter. If inbound SIP requests contain normal headers, Linksys IP phone substitutes those headers with compact headers (if defined by RFC 261) if <Use Compact Header> parameter is set to yes. Defaults to no. Escape Display Name Lets you keep the Display Name private. Select yes if you want the Linksys IP phone to enclose the string (configured in the Display Name) in a pair of double quotes for outbound SIP messages. Any occurrences of or \ in the string is escaped with \ and \\ inside the pair of double quotes. Otherwise, select no. Defaults to yes. SIP-B Enable Enables Sylantro call features. Talk Package Enables support for the Broadsoft Talk Package, which enables a user to answer or resume a call by clicking a button in an external application. Hold Package Enables support for the Broadsoft Hold Package, which enables a user to place a call on hold by clicking a button in an external application. Conference Package Enables support for the Broadsoft Conference Package, which enables a user to start a conference by clicking a button in an external application. Notify Conference If enabled, the unit will send out a NOTIFY with event=conference when starting a conference. RFC 2543 Call Hold If set to yes, unit will include c=0.0.0.0 syntax in SDP when sending a SIP re-INVITE to the peer to hold the call. If set to no, unit will not include the c=0.0.0.0 syntax in the SDP. The unit will always include a=sendonly syntax in the SDP in either case. Defaults to yes. Random REG CID On Reboot If set to yes, the Linksys IP phone uses a different random call-ID for registration after the next software reboot. If set to no, the Linksys IP phone tries to use the same call-ID for registration after the next software reboot. The Linksys IP phone always uses a new random Call-ID for registration after a power-cycle, regardless of this setting. Defaults to no. SIP TCP Port Min Specifies the lowest TCP port number that can be used for SIP sessions. Defaults to 5060. SIP TCP Port Max Specifies the highest TCP port number that can be used for SIP sessions. Defaults to 5080. CTI Enable Enables or disables the Computer Telephone Interface feature provided by some servers. Linksys IP Phone Administrator Guide 5-10 Firmware Version 5.1