4.5.1.1 User AgentUser AgentDescription Specifies the text string to send as the user agent in the headers ofSIP messages.Value Range Max. 64 charactersNote• If "{mac}" is included in this field, it will be replaced with theunit’s MAC address in lower-case.• If "{MAC}" is included in this field, it will be replaced with theunit’s MAC address in upper-case.• If "{MODEL}" is included in this field, it will be replaced with theunit’s model name.• If "{fwver}" is included in this field, it will be replaced with thefirmware version of the unit.• If "{sipver}" is included in this parameter, it will be replaced withthe SIP software version of the unit.Default Value Panasonic-{MODEL}/{fwver} ({mac})Configuration File Reference SIP_USER_AGENT4.5.1.2 NAT IdentityEnable Rport (RFC 3581)Description Selects whether to add the 'rport' parameter to the top Via headerfield value of requests generated.Value Range • Yes• NoDefault Value NoConfiguration File Reference SIP_ADD_RPORTEnable Port Punching for SIPDescription Specifies the interval, in seconds, between transmissions of the KeepAlive packet in order to maintain the NAT binding information for SIPpacket.Value Range 0, 10–3000: DisableDefault Value 0Configuration File Reference PORT_PUNCH_INTVL4.5.1 SIP Settings102 Administrator Guide Document Version 2016-05