Advanced Operational Features6-22 41-001160-03 Rev 00, Release 2.5IP Phone Administrator GuideBlacklist DurationThe Blacklist Duration feature helps to reduce unnecessary delays during proxy/registrar server failures, caused by the IP phone repeatedly sending SIP messagesto a failed server. If you enable this feature, then whenever the IP phone sends aSIP message to a server, and does not get a response, the phone automaticallyadds the server to the blacklist. The IP phone avoids sending messages to anyservers on the blacklist. If all servers are on the blacklist, then the IP phoneattempts to send the message to the first server on the list.You can specify how long failed servers remain on the blacklist in the IP phone’sconfiguration file or in the Aastra Web UI. The default setting is 300 seconds. Ifyou set the duration to 0 seconds, then you disable the blacklist feature.Configuring Blacklist Duration Using the Configuration FilesUse the following parameter to configure the Blacklist Duration in theconfiguration files:• sip blacklist durationConfiguration FilesFor the specific parameters you can set in the configuration files for setting Blacklist Duration, see AppendixA, the section, “Blacklist Duration Setting” on page A-261.
