Specifications

310HD, 320HD and 420HD IP Phones
Administrator's Manual 98 Document #: LTRT-09910
Parameter Description
In the Asymmetric mode, once the
phone is registered to the primary
proxy, it sends keep-alive messages
(using SIP OPTIONS messages) to
the primary proxy. If the primary proxy
does not respond, the phone registers
to the redundant proxy, but continues
sending keep-alive messages to the
primary proxy. If the primary proxy
responds to these keep-alive
messages, the phone re-registers to
the primary proxy. Therefore, the
phone assigns the primary proxy a
higher priority for registration.
 Symmetric mode: both proxies are
assigned the same priority for
registration. In the Symmetric mode,
once the phone is registered to a
proxy, it sends keep-alive messages
to this proxy. The phone switches
proxies only once the proxy to which it
has registered does not respond.
Therefore, the phone assigns both
proxies the same priority for
registration
In both modes, the following applies:
If the phone is not registered (i.e., if the
proxy server¬–redundant or primary–to
which the phone currently tries to register
does not respond), the phone attempts to
register to an alternative proxy. These
attempts continue until the phone
successfully registers.
If this feature is enabled and the user
reboots the phone, the phone registers to
the last proxy to which it was trying to
register, and not necessarily to the
primary proxy.
Note: This parameter is applicable only if
the parameter use_redundant_proxy is
set to 1.