RFC3325;Subscribe ExpireTimeOvertime of resending subscribe packet. Suggest usingthe default config.MWI Number Input the number of the server's voice-‐mail boxRTP Encode Enable/Disable RTP Encrypt.Enable Session Timer Set Enable/Disable Session Timer, whether supportRFC4028.It will refresh the SIP sessions.Answer With SingleCodecEnable/Disable the function when call is incoming, phonereplies SIP message with just one codec which phonesupports.Auto TCP Set to use automatically TCP protocol to guaranteeusability of transport as message is above 1300 byteEnable Strict Proxy Support the special SIP server-‐when phone receives thepackets sent from server