Features Page 77 of 910
IP Line Description, Installation and Maintenance
Note 1: IP Phone to IP Phone calls survive the Call Server failures listed
above.
IP Phone to Media Gateway calls that are connected to media services
and switched-circuit line and trunk terminals are dropped on the TDM
side of the Media Gateway when the CS 1000S Alternate Call Server
performs a cold restart in order to come into service upon failure of the
Primary Call Server, and dropped again when the Primary Call Server
comes back into service.
IP Phone to Media Gateway calls through IP Peer virtual trunk routes are
preserved on the TDM side of the Media Gateway, in some cases, when
the IP Phone is redirected in ACF mode from the main office CS 1000 to
the MG 1000B at the branch office location, or from the Geographic
Redundancy Primary to the Secondary Call Server.
IP Phone to Media Gateway calls are preserved if the Media Gateway to
which the call is established is not affected by the failure, or if there is
cold restart of the Call Server that controls the Media Gateway where the
IP Peer virtual trunk call is established.
• For Call Server call processor types CP PII and CP PIV:
— IP/IP calls survive a cold start on all systems.
— IP/IP and IP/TDM calls survive a warm start on all systems.
— Graceful switchover and graceful failover to the redundant Logical
Call Processor (LCP) side of the Call Server makes the failure
transparent and allows all the calls to survive without any loss.
When the IP Phone with an active call reregisters, the call data is rebuilt if the
Call Server does not know about the call, using the internal IP Phone
information.
The ACF feature for IP Phones meets Joint Interoperability Test Command
(JITC) requirements if the LAN/WAN network is engineered to provide full
redundancy: that is, if a LAN/WAN network component fails, an alternate
path between the clients and LTPS server is provided.