| Description | An entry in the ATM VC Cross Connect table.
This entry is used to model a bi-directional ATM
VC cross-connect cross-connecting two end points.
Step-wise Procedures to set up a VC Cross-connect
Once the entries in the atmVclTable are created,
the following procedures are used
to cross-connect the VCLs together to
form a VCC segment.
(1) The manager obtains a unique
atmVcCrossConnectIndex by reading the
atmVcCrossConnectIndexNext object.
(2) Next, the manager creates a set of one
or more rows in the ATM VC Cross Connect
Table, one for each cross-connection between
two VCLs. Each row is indexed by the ATM
interface port numbers and VPI/VCI values of
the two ends of that cross-connection.
This set of rows specifies the topology of the
VCC cross-connect and is identified by a single
value of atmVcCrossConnectIndex.
Negotiated VC Cross-Connect Establishment
(2a) The manager creates a row in this table by
setting atmVcCrossConnectRowStatus to
createAndWait(5). The agent checks the
requested topology and the mutual sanity of
the ATM traffic parameters and
service categories, i.e., the row creation
fails if:
- the requested topology is incompatible with
associated values of atmVclCastType,
- the requested topology is not supported
by the agent,
- the traffic/service category parameter values
associated with the requested row are
incompatible with those of already existing
rows for this VC cross-connect.
[For example, for setting up
a point-to-point VC cross-connect, the
ATM traffic parameters in the receive direction
of a VCL at the low end of the cross-connect
must equal to the traffic parameters in the
transmit direction of the other VCL at the
high end of the cross-connect,
otherwise, the row creation fails.]
The agent also checks for internal errors
in building the cross-connect.
The atmVcCrossConnectIndex values in the
corresponding atmVclTable rows are filled
in by the agent at this point.
(2b) The manager promotes the row in the
atmVcCrossConnectTable by setting
atmVcCrossConnectRowStatus to active(1). If
this set is successful, the agent has reserved
the resources specified by the ATM traffic
parameter and Service category values
for each direction of the VC cross-connect
in an ATM switch or network.
(3) The manager sets the
atmVcCrossConnectAdminStatus to up(1)
in all rows of this VC cross-connect to
turn the traffic flow on.
One-Shot VC Cross-Connect Establishment
A VC cross-connect may also be established in
one step by a set-request with all necessary
parameter values and atmVcCrossConnectRowStatus
set to createAndGo(4).
In contrast to the negotiated VC cross-connect
establishment which allows for detailed error
checking i.e., set errors are explicitly linked to
particular resource acquisition failures), the
one-shot VC cross-connect establishment
performs the setup on one operation but does
not have the advantage of step-wise error
checking.
VC Cross-Connect Retirement
A VC cross-connect identified by a particular
value of atmVcCrossConnectIndex is released by:
(1) Setting atmVcCrossConnectRowStatus of all rows
identified by this value of
atmVcCrossConnectIndex to destroy(6).
The agent may release all
associated resources, and the
atmVcCrossConnectIndex values in the
corresponding atmVclTable row are removed.
Note that a situation when only a subset of
the associated rows are deleted corresponds
to a VC topology change.
(2) After deletion of the appropriate
atmVcCrossConnectEntries, the manager may
set atmVclRowStatus to destroy(6) the
associated VCLs. The agent releases
the resources and removes the associated
rows in the atmVclTable.
VC Cross-Connect Reconfiguration
At the discretion of the agent, a VC
cross-connect may be reconfigured by
adding and/or deleting leafs to/from
the VC topology as per the VC cross-connect
establishment/retirement procedures.
Reconfiguration of traffic/service category parameter
values requires release of the VC cross-connect
before those parameter values may by changed
for individual VCLs. |
| Description | An entry in the ATM VC Cross Connect table.
This entry is used to model a bi-directional ATM
VC cross-connect cross-connecting two end points.
Step-wise Procedures to set up a VC Cross-connect
Once the entries in the atmVclTable are created,
the following procedures are used
to cross-connect the VCLs together to
form a VCC segment.
(1) The manager obtains a unique
atmVcCrossConnectIndex by reading the
atmVcCrossConnectIndexNext object.
(2) Next, the manager creates a set of one
or more rows in the ATM VC Cross Connect
Table, one for each cross-connection between
two VCLs. Each row is indexed by the ATM
interface port numbers and VPI/VCI values of
the two ends of that cross-connection.
This set of rows specifies the topology of the
VCC cross-connect and is identified by a single
value of atmVcCrossConnectIndex.
Negotiated VC Cross-Connect Establishment
(2a) The manager creates a row in this table by
setting atmVcCrossConnectRowStatus to
createAndWait(5). The agent checks the
requested topology and the mutual sanity of
the ATM traffic parameters and
service categories, i.e., the row creation
fails if:
- the requested topology is incompatible with
associated values of atmVclCastType,
- the requested topology is not supported
by the agent,
- the traffic/service category parameter values
associated with the requested row are
incompatible with those of already existing
rows for this VC cross-connect.
[For example, for setting up
a point-to-point VC cross-connect, the
ATM traffic parameters in the receive direction
of a VCL at the low end of the cross-connect
must equal to the traffic parameters in the
transmit direction of the other VCL at the
high end of the cross-connect,
otherwise, the row creation fails.]
The agent also checks for internal errors
in building the cross-connect.
The atmVcCrossConnectIndex values in the
corresponding atmVclTable rows are filled
in by the agent at this point.
(2b) The manager promotes the row in the
atmVcCrossConnectTable by setting
atmVcCrossConnectRowStatus to active(1). If
this set is successful, the agent has reserved
the resources specified by the ATM traffic
parameter and Service category values
for each direction of the VC cross-connect
in an ATM switch or network.
(3) The manager sets the
atmVcCrossConnectAdminStatus to up(1)
in all rows of this VC cross-connect to
turn the traffic flow on.
One-Shot VC Cross-Connect Establishment
A VC cross-connect may also be established in
one step by a set-request with all necessary
parameter values and atmVcCrossConnectRowStatus
set to createAndGo(4).
In contrast to the negotiated VC cross-connect
establishment which allows for detailed error
checking i.e., set errors are explicitly linked to
particular resource acquisition failures), the
one-shot VC cross-connect establishment
performs the setup on one operation but does
not have the advantage of step-wise error
checking.
VC Cross-Connect Retirement
A VC cross-connect identified by a particular
value of atmVcCrossConnectIndex is released by:
(1) Setting atmVcCrossConnectRowStatus of all rows
identified by this value of
atmVcCrossConnectIndex to destroy(6).
The agent may release all
associated resources, and the
atmVcCrossConnectIndex values in the
corresponding atmVclTable row are removed.
Note that a situation when only a subset of
the associated rows are deleted corresponds
to a VC topology change.
(2) After deletion of the appropriate
atmVcCrossConnectEntries, the manager may
set atmVclRowStatus to destroy(6) the
associated VCLs. The agent releases
the resources and removes the associated
rows in the atmVclTable.
VC Cross-Connect Reconfiguration
At the discretion of the agent, a VC
cross-connect may be reconfigured by
adding and/or deleting leafs to/from
the VC topology as per the VC cross-connect
establishment/retirement procedures.
Reconfiguration of traffic/service category parameter
values requires release of the VC cross-connect
before those parameter values may by changed
for individual VCLs. |