Yealink SIP-T2 SERIES Administrator's Manual page 686

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
X is equal to 1 (for SIP-T19(P) E2/CP860)
Note: It is not applicable to outbound proxy servers.
Web User Interface:
None
Phone User Interface:
None
account.X.outbound_proxy_fallback_interval
Description:
Configures the time interval (in seconds) for the IP phone to detect whether the
working outbound proxy server is available by sending the registration request after
the fallback server takes over call control.
X ranges from 1 to 16 (for SIP VP-T49G/SIP-T48G/T46G/T29G)
X ranges from 1 to 12 (for SIP-T42G)
X ranges from 1 to 6 (for SIP-T41P/T27P)
X ranges from 1 to 3 (for SIP-T40P/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
X is equal to 1 (for SIP-T19(P) E2/CP860)
Example:
account.1.outbound_proxy_fallback_interval = 3600
Note: It is only applicable to outbound proxy servers.
Web User Interface:
Account->Register->Proxy Fallback Interval
Phone User Interface:
Menu->Settings->Advanced Settings->Accounts->Proxy Fallback Interval
account.X.sip_server.Y.failback_mode
(X ranges from 1 to 16, Y ranges from 1 to 2)
Description:
Configures the mode for the IP phone to retry the primary server in failover for
account X.
0-newRequests: all requests are sent to the primary server first, regardless of the last
server that was used.
1-DNSTTL: the IP phone will send requests to the last registered server first. If the time
defined by DNSTTL on the registered server expires, the phone will retry to send
requests to the primary server.
664
Parameters Permitted Values Default
Integer from 0 to
3600
65535
0, 1, 2 or 3 0