The PIC failover procedure for the BGF assures service continuity
in case of a service PIC failure. The BGF architecture provides both
a 1:1 redundancy model and a 1:N redundancy model for service PICs.
In the 1:1 redundancy model, there is one primary service PIC
and one secondary service PIC that acts as a backup. If the primary
service PIC fails, the Routing Engine allocates the secondary service
PIC, and the software switches over to the secondary service PIC.
The pgcpd process continues to provide the PGCP services as if the
service PIC has restarted. All states and sessions are lost, but new
calls are accepted. When the failed service PIC recovers, it does
not take over from the redundant PIC.
In the 1:N redundancy model, you can define one PIC as the secondary
of many primary PICs. In this model, after the secondary PIC becomes
active, all other primary PICs are left without a secondary PIC. Even
when the primary PIC recovers, it does not become a redundant PIC
to all of the primary PICs. A recovered primary PIC can replace only
the same secondary PIC that previously replaced it. This functionality
means that administrative involvement is usually required after a
failover event happens.
Procedure in Case of Service PIC Failure
If a service PIC fails, the following procedure takes place:
Active calls are lost.
The BGF notifies the gateway controller of the
failure using an FO/904 ServiceChange message.
The BGF receives an acknowledgment for the FO/904
message from the gateway controller.
The redundant service PIC (rsp) mechanism allocates
the secondary PIC and makes the secondary PIC the new primary PIC.
The new primary PIC establishes the IPC connection
to the pgcpd process on the routing engine.
The pgcpd process issues an RS/902 registration
message to the gateway controller.
The pgcpd process receives an acknowledgment of
the registration message from the gateway controller.
The BGF is ready to accept and process new H.248
commands.
Configuring the BGF for PIC Redundancy
To configure PIC failover, you configure a redundancy services
PIC (rsp) interface that specifies which service PIC is the primary
PIC and which service PIC is the secondary PIC. In the service set
configuration for the PGCP service, the service set points to the
rsp interface as the next-hop service interface.
Configuring the Redundancy Services PIC (rsp) Interface
To configure, create a redundancy services PIC (rsp) interface,
and specify the primary and secondary service PIC and the inside and
outside service domains.
Step-by-Step Procedure
To configure the rsp interface:
Configure the interface, and enter edit mode
for the interface.
[edit]
user@host#edit interfaces rsp1
Specify the service PIC that is to be
the primary PIC.
[edit interfaces rsp1]
user@host#set redundancy-options primary sp-1/2/0
Specify the service PIC that is to be
the secondary PIC.
Configure a logical unit and specify
the protocol family.
[edit interfaces rsp1]
user@host#set unit 10 family inet
Set the service domain of the logical
unit to inside. This unit number must match the unit number of the
inside service interface configured in the service set.
[edit interfaces rsp1]
user@host#set unit 10 service-domain inside
Configure another logical unit and specify
the protocol family.
[edit interfaces rsp1]
user@host#set unit 20 family inet
Set the service domain of the logical
unit to outside. This unit number must match the unit number of the
outside service interface configured in the service set.
[edit interfaces rsp1]
user@host#set unit 20 service-domain outside
Configuring the Service Set for Redundant
Service PICS
When you configure your service set, specify the rsp interface
as the next-hop service.
Step-by-Step Procedure
To configure a service set for redundancy:
Create a service set configuration.
[edit services]
user@host#edit service-set bgf-svc-set
Configure service set as a next-hop service
set.
[edit services service-set bgf-svc-set]
user@host#edit next-hop-service
Specify the rsp interface to the inside
network. This unit number must match the unit number of the inside
service domain configured in the rsp interface.
Specify the rsp interface to the outside
network. This unit number must match the unit number of the outside
service domain configured in the rsp interface.
