You can configure MTP to act as multiple point codes to the network and receive and send inbound traffic destined to a number of point codes. This configuration can be used to:
Bridge multiple networks, as in a gateway application
Provide a service from a single application to multiple networks
Test applications
This topic presents:
To configure multiple OPC emulation for a single network in MTP, configure an up route for each of the point codes to be emulated. The following sample configuration file shows how to configure MTP to act as point codes 1.1.100, 1.2.200, and 1.3.300 to the network. The modifications are shown in bold type. Higher layer traffic for the extra point codes is passed to a registered (bound) upper layer rather than being discarded as undeliverable. In this configuration, MTP is 1.1.100 to both adjacent signaling points for MTP management messages. Links and linksets still have an OPC equal to the general OPC of 1.1.100.
<General Parameters>
NODE_TYPE STP
POINT_CODE 1.1.100 # This node’s point code
#
#Link Parameters
#
LINK T1 # Link 0 to STP 1.1.0
LINK_SET 1
ADJACENT_DPC 1.1.0
END
#
LINK T2 # Link 1 to STP 1.1.1
LINK_SET 2
ADJACENT_DPC 1.1.1
END
#
#Routing Parameters
#
# Route UP from network to applications on this node
#
ROUTE 0
DPC 1.1.100 # this node
DIRECTION UP
END
#
ROUTE 1
DPC 1.1.0 # STP 1.1.0
END
#
ROUTE 2
DPC 1.1.1 # STP 1.1.1
END
#
ROUTE 3
DPC 1.1.200 # Route to non-adjacent 1.1.200
END
#
ROUTE 4
DPC 1.2.200 # emulated point code
DIRECTION UP
END
#
ROUTE 5
DPC 1.3.300 # emulated point code
DIRECTION UP
END
#
#
# Link set Parameters
#
LINK_SET_DESCRIPTOR 1
ADJACENT_DPC 1.1.0 # link set to STP 1.1.0
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
END
#
LINK_SET_DESCRIPTOR 2
ADJACENT_DPC 1.1.1 # link set to STP 1.1.1
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
END
While the previous configuration allows upper layers to receive messages directed to 1.2.200 and 1.3.300, this is not sufficient for all upper layers to operate properly (for example, the ISUP layer). ISUP requires that a RESUME indication be returned for each OPC/DPC combination for which it has circuits defined, so it can activate those circuits and respond to incoming IAM messages. In the previous configuration, when linkset 1 or 2 become available, only one RESUME indication with OPC/DPC (1.1.100/1.1.200) is generated. This does not include the RESUME indications generated for the STPs. There is only one down route that is not to an STP, and that route uses the general OPC by default.
MTP generates a RESUME for each available down route using the OPC and DPC associated with that route. Therefore, if you are using ISUP with multiple OPCs or your own application requires RESUMES for all OPC/DPC combinations, you must add a down route for each combination.
The following example shows how to add down routes so that RESUMES are generated for each OPC/DPC combination. The modifications are shown in bold type.
<General Parameters>
NODE_TYPE STP
POINT_CODE 1.1.100 # This node’s point code
#
#Link Parameters
#
LINK T1 # Link 0 to STP 1.1.0
LINK_SET 1
ADJACENT_DPC 1.1.0
END
#
LINK T2 # Link 1 to STP 1.1.1
LINK_SET 2
ADJACENT_DPC 1.1.1
END
#
#Routing Parameters
#
# Route UP from network to applications on this node
#
ROUTE 0
DPC 1.1.100 # this node
DIRECTION UP
END
#
ROUTE 1
DPC 1.1.0 # STP 1.1.0
END
#
ROUTE 2
DPC 1.1.1 # STP 1.1.1
END
#
ROUTE 3
DPC 1.1.200 # Route to non-adjacent 1.1.200
END
#
ROUTE 4
DPC 1.2.200 # emulated point code
DIRECTION UP
END
#
ROUTE 5
DPC 1.3.300 # emulated point code
DIRECTION UP
END
#
ROUTE 6
OPC 1.2.200 # emulated point code
DPC 1.1.200 # Route to non-adjacent 1.1.200
END
#
ROUTE 7
OPC 1.3.300 # emulated point code
DPC 1.1.200 # Route to non-adjacent 1.1.200
END
#
#
# Link set Parameters
#
LINK_SET_DESCRIPTOR 1
ADJACENT_DPC 1.1.0 # link set to STP 1.1.0
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
ROUTE_NUMBER 6
ROUTE_NUMBER 7
END
#
LINK_SET_DESCRIPTOR 2
ADJACENT_DPC 1.1.1 # link set to STP 1.1.1
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
ROUTE_NUMBER 6
ROUTE_NUMBER 7
END
In the previous configuration RESUMES are generated for three OPC/DPC combinations (not including the RESUMES for the adjacent STPs). These combinations are:
|
OPC |
DPC |
|
1.1.100 |
1.1.200 |
|
1.2.200 |
1.1.200 |
|
1.3.300 |
1.1.200 |
If MTP needs to emulate different point codes to directly connected signaling points (as in a gateway application), the configuration must include the emulated OPCs in the link and linkset definitions, in addition to the additional up routes. The following example shows the modifications in bold type. In this configuration, MTP acts as 1.1.100 to the STP 1 network and 1.2.200 to the STP 2 network. Traffic is received for all three point codes from either network.
<General Parameters>
NODE_TYPE STP
POINT_CODE 1.1.100 # This node’s point code
#
#Link Parameters
#
LINK T1 # Link 0 to STP 1.1.0
LINK_SET 1
ADJACENT_DPC 1.1.0
OPC 1.1.100
END
#
LINK T1 # Link 1 to STP 1.1.1
LINK_SET 2
ADJACENT_DPC 1.1.1
OPC 1.2.200
END
#
#Routing Parameters
#
# Route UP from network to applications on this node
#
ROUTE 0
DPC 1.1.100 # this node
DIRECTION UP
END
#
ROUTE 1
DPC 1.1.0 # STP 1.1.0
END
#
ROUTE 2
DPC 1.1.1 # STP 1.1.1
END
#
ROUTE 3
DPC 1.1.200 # Route to non-adjacent 1.1.200
END
#
ROUTE 4
DPC 1.2.200 # emulated point code
DIRECTION UP
END
#
ROUTE 5
DPC 1.3.300 # emulated point code
DIRECTION UP
END
#
#
# Link set Parameters
#
LINK_SET_DESCRIPTOR 1
ADJACENT_DPC 1.1.0 # link set to STP 1.1.0
OPC 1.1.100
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
END
#
LINK_SET_DESCRIPTOR 2
ADJACENT_DPC 1.1.1 # link set to STP 1.1.
OPC 1.2.200
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
END
The OPC lines for link 1 and linkset 1 are not required since the OPC always defaults to the general configuration point code when not specified. However, the OPC makes it clearer that point code emulation is being used and that the linksets (and their respective links) are using different OPCs. If an OPC different from the general configuration point code is specified in a linkset or in one or more of its links but not both, the specified point code is propagated to the entities where OPC is unspecified. If two different OPCs are specified for a linkset and for one or more of its links, an alarm is generated and the second entity encountered is not configured.
To avoid confusion when emulating different point codes to directly connected signaling points, specify the OPCs in each link and linkset and make sure they match between the linkset and the links.
In the previous configurations, outbound traffic is routed by destination point code (DPC) and signaling link selector (SLS) only. For multiple network configurations, use OPC_ROUTING = TRUE to specify that outbound routing take into account the OPC.
The following configuration defines two routes to 1.1.200 with differing OPCs. Traffic to 1.1.200 with an OPC of 1.1.100 is routed over link/linkset 1, and traffic to 1.1.200 with an OPC of 1.2.200 is routed over link/linkset 2. The modifications are shown in bold type.
<General Parameters>
NODE_TYPE STP
POINT_CODE 1.1.100 # This node’s point code
OPC_ROUTING TRUE
#
#Link Parameters
#
LINK T1 # Link 0 to STP 1.1.0
LINK_SET 1
ADJACENT_DPC 1.1.0
OPC 1.1.100
END
#
LINK T2 # Link 1 to STP 1.1.1
LINK_SET 2
ADJACENT_DPC 1.1.1
OPC 1.2.200
END
#
#Routing Parameters
#
# Route UP from network to applications on this node
#
ROUTE 0
DPC 1.1.100 # this node
DIRECTION UP
END
#
ROUTE 1
DPC 1.1.0 # STP 1.1.0
OPC 1.1.100
END
#
ROUTE 2
DPC 1.1.1 # STP 1.1.1
OPC 1.2.200
END
#
ROUTE 3
DPC 1.1.200 # Route to non-adjacent 1.1.200
OPC 1.1.100
END
#
ROUTE 4
DPC 1.1.200 # Route to non-adjacent 1.1.200
OPC 1.2.200
END
#
ROUTE 5
DPC 1.2.200 # emulated point code
DIRECTION UP
END
#
ROUTE 6
DPC 1.3.300 # emulated point code
DIRECTION UP
END
#
#
# Link set Parameters
#
LINK_SET_DESCRIPTOR 1
ADJACENT_DPC 1.1.0 # link set to STP 1.1.0
OPC 1.1.100
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 3
END
#
LINK_SET_DESCRIPTOR 2
ADJACENT_DPC 1.1.1 # link set to STP 1.1.1
OPC 1.2.200
ROUTE_NUMBER 1
ROUTE_NUMBER 2
ROUTE_NUMBER 4
END
If OPC_ROUTING is FALSE, traffic to 1.1.200 is shared across linksets 1 and 2 because the OPC is not taken into account for outbound routing.