AASTRA 6700i series, 9143, 9480i, 9480i CT SIP Administrator Guide EN - Manual (Page 649)

6-22 41-001343-01 Rev 03, Release 3.2.2
Blacklist Duration
The Blacklist Duration feature helps to reduce unnecessary delays during proxy/registrar server
failures, caused by the IP phone repeatedly sending SIP messages to a failed server. If you
enable this feature, then whenever the IP phone sends a SIP message to a server, and does not get
a response, the phone automatically adds the server to the blacklist. The IP phone avoids sending
messages to any servers on the blacklist. If all servers are on the blacklist, then the IP phone
attempts 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’s configuration
file or in the Aastra Web UI. The default setting is 300 seconds (5 minutes). If you set the
duration to 0 seconds, then you disable the blacklist feature.
Configuring Blacklist Duration Using the Configuration Files
Use the following parameter to configure the Blacklist Duration in the configuration files:
• sip blacklist duration
Configuration Files
For the specific parameters you can set in the configuration files for setting Blacklist Duration, see Appendix
A, the section,
“Blacklist Duration Setting” on page A-240.