VP-12, VP-12P IP phones. Operation manual
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The phone may operate with a single main SIP-proxy and up to four redundant SIP-proxies. For
exclusive operations with the main SIP-proxy, 'Parking' and 'Homing' modes are identical. In this case,
if the main SIP-proxy fails, it will take time to restore its operational status.
For operations with redundant SIP-proxies, 'Parking' and 'Homing' modes will work as follows:
The gateway sends INVITE message to the main SIP-proxy address when performing outgoing call,
and REGISTER message when performing registration attempt. If on expiration of 'Invite total timeout'
there is no response from the main SIP-proxy or response 408 or 503 is received, the phone sends
INVITE (or REGISTER) message to the first redundant SIP-proxy address. If it is not available, the
request is forwarded to the next redundant SIP-proxy and so forth. When available redundant SIP-
proxy is found, registration will be renewed on that SIP-proxy.
Next, the following actions will be available depending on the selected redundancy mode:
In the 'parking' mode, the main SIP-proxy management is absent, and the phone will continue
operation with the redundant SIP-proxy even when the main proxy operation is restored. If the
connection to the current SIP-proxy is lost, querying of the subsequent SIP-proxies will be continued
using the algorithm described above. If the last redundant SIP-proxy is not available, the querying will
continue in a cycle, beginning from the main SIP-proxy.
In the 'homing' mode, three types of the main SIP-proxy management are available: periodic
transmission of OPTIONS messages to its address, periodic transmission of REGISTER messages to
its address, or transmission of INVITE request when performing outgoing call. First of all, INVITE
request is sent to the main SIP-proxy, and if it is unavailable, then the next redundant one, etc.
Regardless of the management type, when the main SIP-proxy operation is restored, the gateway will
use it to renew its registration. The gateway will begin operation with the main SIP-proxy.
•
Proxy Server
– network address of a SIP server—device that manages access to provider's phone
network for all subscribers. You may specify IP address as well as the domain name (specify SIP server
UDP port after the colon, default value is 5060).
•
Registration
–
when selected, register ports that utilize this profile on registration server.
•
Registration Server
–
network address of a device that is used for registration of all phone network
subscribers in order to provide them with the communication services (specify registration server UDP
port after the colon, default value is 5060). You may specify IP address as well as the domain name. As
a rule, registration server is physically co-located with SIP proxy server (they have the same address).
•
Home Server Check Method
– select availability control method for the primary SIP server in 'Homing'
mode:
•
Invite –
control via transmission of INVITE request to its address when performing an outgoing
call.
•
Register –
control via periodic transmission of REGISTER messages to its address.
•
Options –
control via periodic transmission of OPTIONS messages to its address.
•
Home Server Keepalive Timeout, s
– periodic message transmission interval in seconds; used for
primary SIP server availability check.
•
Transport
– select protocol for SIP messages transport.
•
Invite Initial Timeout, ms
– a time interval between first INVITE transmission and the second one in case
there is no answer on the first INVITE (ms). For the following INVITE requests (third, forth, fifth etc.) the
interval will be increased twice (i.e. if the value is 300 ms, the second INVITE will be sent in 300 ms, the
third – in 600 ms, the forth – in 1200 ms, etc.);
•
Invite Initial Max Timeout, ms
– the maximum time interval for retransmitting non-INVITE requests and
responses on INVITE requests;
•
Invite Total Timeout, ms
– common timeout of INVITE requests transmissition (ms). When the timeout is
expired, it is defined that the route is not available. INVITE requests retranslation is limited for availability
definition as well.
