Controlling ServiceChange Commands Sent from the Virtual BGF
to the Gateway Controller
For seamless interoperability between the BGF and gateway controller
devices, you can control the method and reason that the virtual BGF
includes in ServiceChange commands that it sends to the gateway controller.
You can also prevent the system from being overloaded with messages
for certain state changes by specifying that the virtual BGF not send
a request or notification when those changes occur.
You can specify the method and reason that the virtual BGF includes
in ServiceChange commands when the state of one of the following changes:
Control associations
Virtual interfaces
Contexts
Control Association States
A control association is a relationship where the gateway controller
is controlling the virtual BGF. Each virtual BGF has only one control
association at any time.
The control association is in the Disconnected state. No gateway
controller is controlling the virtual BGF, and incoming H.248 messages
are ignored. The control association remains disconnected as long
as the virtual BGF is Out-of-Service.
Depending on what caused the virtual BGF to become Out-of-Service,
the virtual BGF either drops H.248 commands or answers them with a
port-unreachable ICMP error.
Connecting
The control association is in Connecting state between the time
the virtual BGF sends a registration request to the gateway controller
and the time the gateway controller accepts, rejects, or aborts the
request.
The virtual BGF rejects incoming H.248 commands while the control
association is in the Connecting state with error # 505: “Transaction
Request Received before a ServiceChange Reply has been received”.
Draining
The control association enters the Draining state when an administrator
instructs the virtual BGF to gracefully transition from In-Service
to Out-of-Service. The gateway controller transitions to Out-of-Service
when the controlling gateway controller subtracts all of the virtual
BGF’s H.248 terminations.
The virtual BGF accepts only Subtract and AuditValue commands
from the controlling gateway controller. It rejects all other commands
with error # 502: “Not Ready”.
When the state of a control association changes, the virtual
BGF can send the following types of ServiceChange commands to the
gateway controller:
Registration Requests—The virtual BGF sends a Registration
Request ServiceChange command to request that a gateway controller
become its controlling gateway controller. The virtual BGF sends these
requests when a control association enters the Connecting state.
Unregistration Messages—The virtual BGF sends an
Unregistration ServiceChange command to its controlling gateway controller
when it transitions to the Out-of-Service (Disconnected) service state
because of an administration operation or a failure. The failure can
be the result of a services PIC, Flexible PIC Concentrator (FPC),
or MS-DPC failure, or because the PIC or DPC was powered off or removed.
Notification Messages—The virtual BGF sends a notification
ServiceChange command to its controlling gateway controller when the
control association transitions between the Connected and Draining
states and vice versa.
Method and Reason Options for Control Association
State Changes
You can control the ServiceStateMethod and ServiceStateReason
that the virtual BGF includes in ServiceChange commands for control
associations.
You can use the CLI to specify the method and reason that the
virtual BGF includes in ServiceChange commands for control associations. Table 8 shows
the method and reason options available for each reported state and
the events that led to the report.
Table 8: Options
for Method and Reason in ServiceChange Commands for Control Associations
Reported Association State
Event Leading to Report
Options
Embedded H.248 Reason
Explanation
Disconnect
Controller failure
FL/909
Gateway controller impending failure
Virtual BGF is reregistering with a new gateway controller following
a disconnection of the virtual BGF and gateway controller.
RS/902
Warm boot
Virtual BGF is reregistering with a new gateway controller following
a disconnection of the virtual BGF and gateway controller.
Reconnect
DC/900
Service restored
Virtual BGF is registering with the last controlling gateway
controller following a disconnection of the virtual BGF and gateway
controller.
RS/902
Warm boot
Virtual BGF is transitioning to In-Service, and the previously
installed state is retained.
Down
Administrative
FO/905
Termination taken out of service
Virtual BGF is transitioning to Out-of-Service because of an
administrative operation.
FO/908
VPG impending failure
Virtual BGF root termination transitioned to Out-of-Service
and is unable to process request.
none
No message is sent for this event.
Failure
FO/904
Termination malfunctioning
Virtual BGF is transitioning to Out-of-Service because of a
failure.
FO/908
VPG impending failure
Virtual BGF root termination transitioned to Out-of-Service
because of a failure.
none
No message is sent for this event.
Graceful
GR/905
Termination taken out of service
The control association entered the Draining state because of
an administrative operation.
none
No message is sent for this event.
Up
Cancel graceful
RS/908
Cancel graceful
The control association transitioned from the Draining state
to the Forwarding state.
none
No message is sent for this event.
Cold failover
FL/920
Cold failover
Virtual BGF is registering following a graceful Routing Engine
switchover. The previously installed state is reset.
RS/901
Cold boot
Virtual BGF is transitioning to In-Service. The previously installed
state is not retained.
Warm failover
FL/919
Gateway controller impending failure
Virtual BGF is registering with a new gateway controller following
a disconnection of the virtual BGF and gateway controller.
RS/902
Warm boot
Virtual BGF is transitioning to In-Service, and the previously
installed state is retained.
Configuring the Method and Reason in ServiceChange
Commands for Control Associations
Step-by-Step Procedure
To configure the method and reason in ServiceChange commands
for control associations:
Access the configuration of the service change
control association indications properties.
Specify the method and reason that the
virtual BGF includes in Registration Request ServiceChange commands
when it attempts to reregister with the gateway controller or register
with a new gateway controller after the control association is disconnected.
Specify the method and reason that the
virtual BGF includes in Registration Request ServiceChange commands
when it attempts to reregister with the gateway controller or register
with a new gateway controller after the control association is disconnected.
Specify the method and reason that the
virtual BGF includes in Unregistration Messages in ServiceChange commands
that it sends to the gateway controller when a control association
transitions to Out-of-Service because of an administrative operation.
Specify the method and reason that the
virtual BGF includes in Unregistration Messages in ServiceChange commands
that it sends to the gateway controller when a control association
transitions to Out-of-Service because of a failure.
Specify the method and reason that the
virtual BGF includes in Notification ServiceChange commands that it
sends to the gateway controller when the control association transitions
from In-Service to Out-of-Service-Graceful.
Specify the method and reason that the
virtual BGF includes in Notification ServiceChange commands that it
sends to the gateway controller when the control association has returned
to the Connected state.
Specify the method and reason that the
virtual BGF includes in Registration ServiceChange commands when it
attempts to register with a new gateway controller following a cold
failover.
Specify the method and reason that the
virtual BGF includes in Registration ServiceChange commands when it
attempts to register with a new gateway controller following a warm
failover.
A virtual interface is in the Blocked state when the interface
is Out-of-Service.
While a virtual interface is in the Blocked state, all VPGs
do not add new terminations using the interface. Likewise, the virtual
BGF rejects H.248 commands other than Subtract and AuditValue commands
on existing terminations on the interface. The error that the virtual
BGF returns for commands that it rejects depends on the reason that
caused the virtual interface to be Out-of-Service:
Error #502: "Not ready"—If the virtual
interface is Out-of-Service because of an administrative operation.
Error #529: "Internal hardware failure in PG"—If the virtual interface is Out-of-Service because of a failure.
Forwarding
A virtual interface is in the Forwarding state when it is functioning
normally. All gates are using the interface process data flows according
to the H.248 properties installed on them.
Draining
A virtual interface enters the Draining state when an administrator
instructs the virtual interface to gracefully transition from In-Service
to Out-of-Service. The virtual interface automatically transitions
to Out-of-Service when it is no longer used by any termination in
any of the virtual BGFs.
A virtual interface that is in the Draining state is In-Service
and existing gates process data flows normally. However, as in the
Blocked state, the virtual BGFs do not add new terminations using
that virtual interface or to perform any command other than Subtract
and AuditValue on existing terminations on the interface. If the virtual
BGF receives other commands, it replies with error #502: "Not
ready".
When the state of a virtual interface changes, the virtual BGF
can send the following types of ServiceChange commands to the gateway
controller:
Service-Restoration—The virtual BGF sends Service-Restoration
ServiceChange commands when a virtual interface transitions to the
In-Service service state; that is, it transitions from the Blocked
state to the Forwarding operational state.
Service-Interruption—The virtual BGF sends Service-Interruption
ServiceChange commands when a virtual interface transitions to the
Out-of-Service, or Blocked, service state.
Notification Messages—The virtual BGF sends Notification
ServiceChange commands when a virtual interface transitions between
the Forwarding and Draining states and vice versa.
Method and Reason Options for Virtual Interface
State Changes
You can control the ServiceStateMethod and ServiceStateReason
that the virtual BGF includes in ServiceChange commands for virtual
interface state changes.
You can use the CLI to specify the method and reason that the
virtual BGF includes in ServiceChange commands for virtual interfaces. Table 10 explains
the method and reason options available for each reported state and
the events that led to the report.
Table 10: Options
for Method and Reason in ServiceChange Commands for Virtual Interfaces
Reported State
Event Leading to Report
Options
Embedded H.248 Reason
Explanation
Virtual interface down
Administrative
FO/905
Termination taken out of service
Virtual interface is transitioning to Out-of-Service because
of an administrative operation.
FO/906
Loss of lower-layer connectivity
Virtual interface is transitioning to Out-of-Service because
of a loss of layer 2 connectivity caused by the logical or physical
interface being administratively disabled.
none
No message is sent for this event.
Failure
FO/904
Termination malfunctioning
Virtual interface is transitioning to Out-of-Service because
of an internal failure.
FO/906
Loss of lower-layer connectivity
Virtual interface is transitioning to Out-of-Service because
of a loss of layer 2 connectivity on the logical or physical interface.
none
No message is sent for this event.
Graceful
GR/905
Termination taken out of service
Virtual interface has entered the Draining state.
none
No message is sent for this event.
Link loss
FO/906
Loss of lower-layer connectivity
Virtual interface is transitioning to Out-of-Service because
of a loss of layer 2 connectivity on the logical or physical interface.
none
No message is sent for this event.
Virtual interface up
Cancel graceful
RS/918
Cancel graceful
Virtual interface has returned to the Forwarding state.
none
No message is sent for this event.
warm
RS/900
Service restored
Virtual interface has become In-Service and is in the Forwarding
state.
none
No message is sent for this event.
Configuring the Method and Reason in ServiceChange
Commands for Virtual Interfaces
Step-by-Step Procedure
To configure the method and reason in ServiceChange commands
for virtual interfaces:
Access the configuration of the service change
virtual interface indications properties.
Specify the method and reason that the
virtual BGF includes in Service-Interruption ServiceChange commands
that it sends to the gateway controller when a virtual interface changes
to Out-of-Service because of an administrative operation.
Specify the method and reason that the
virtual BGF includes in Service-Interruption ServiceChange commands
that it sends to the gateway controller when a virtual interface transitions
to Out-of-Service because of a failure.
Specify the method and reason that the
virtual BGF includes in Notification ServiceChange commands that it
sends to the gateway controller when a virtual interface transitions
between the Forwarding and Draining states.
Specify the method and reason that the
virtual BGF includes in Service-Interruption ServiceChange commands
that it sends to the gateway controller when the virtual interface
transitions to Out-of-Service because of a link loss.
Specify the method and reason that the
virtual BGF includes in Notification ServiceChange commands that it
sends to the gateway controller when the virtual interface transitions
from the Draining state to the Forwarding state.
Specify the method and reason that the
virtual BGF includes in Service-Restoration ServiceChange commands
that it sends to the gateway controller when a virtual interface transitions
to In-Service.
The virtual BGF sends context Service-Interruption messages
when the gates of a specific context no longer provide their configured
service. When such a message is issued, both terminations included
in the context become Out-of-Service.
You can use the CLI to specify the method and reason that the
virtual BGF includes in Service-Interruption ServiceChange commands
that it sends to the gateway controller when a state loss occurs. Table 11 describes the method
and reason options available.
Table 11: Options
for Method and Reason in ServiceChange Commands for Specific Contexts
Reported State
Event Leading to Report
Options
Embedded H.248 Reason
Explanation
State loss
Mismatch between pgcpd process and Service PIC or MS-DPC states
FO/910
State loss because of a media failure
A mismatch between the pgcpd process and the services PIC or
MS-DPC states was detected on one or more of the context’s gates.
FO/915
State loss
A mismatch between the pgcpd process and the services PIC or
MS-DPC states was detected on one or more of the context’s gates.
none
No message is sent for this event.
Configuring the Method and Reason in ServiceChange
Commands for Contexts
Step-by-Step Procedure
To configure the method and reason in ServiceChange commands
for contexts:
Access the configuration of the service change
context indications properties.
Specify the method and reason that the
virtual BGF includes in Service-Interruption ServiceChange commands
that it sends to the gateway controller after a state loss on a specific
context.