Configuring Advanced Features729Parameters Permitted Values DefaultNonePhone User Interface:Noneaccount.X.static_cache_pri 0 or 1 0Description:Configures whether preferentially to use the static DNS cache for domain name resolutionof the server for account X.0-Use domain name resolution from the DNS server preferentially1-Use static DNS cache preferentiallyX ranges from 1 to 16 (for SIP-T48G/T48S/T46G/T46S/T29G)X ranges from 1 to 12 (for SIP-T42G/T42S)X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G)X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G)X ranges from 1 to 2 (for SIP-T21(P) E2)X is equal to 1 (for SIP-T19(P) E2)Example:account.1.static_cache_pri = 1Web User Interface:NonePhone User Interface:NoneReal-Time Transport Protocol (RTP) PortsThe Real-time Transport Protocol (RTP) is a network protocol for delivering audio over IPnetworks. The phone is compatible with RFC 1889 - RTP: A Transport Protocol for Real-TimeApplications - and the updated RFC 3550. It treats all RTP streams as bi-directional from acontrol perspective and expects that both RTP end points will negotiate the respectivedestination IP addresses and ports.You can specify the IP phone’s RTP port range. Since the IP phone supports conferencing andmultiple RTP streams, it can use several ports concurrently. The UDP port used for RTP streamsis traditionally an even-numbered port. For example, the default RTP min port on the IP phonesis 11780. The first voice session sends RTP on port 11780. Additional calls would then use ports11782, 11784, 11786, etc. up to the max port.
