Cisco Cisco ONS 15454 SONET Multiservice Provisioning Platform (MSPP) Guía De Diseño
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SDCC or Line DCC (LDCC). Unused SDCCs and LDCCs can be used to tunnel DCCs from
third-party equipment across ONS 15454 networks.
The SDCC is defined in the first STS-1 of an STS-N frame. Looking at the Section Overhead in
Table 2-4 you will find the D1, D2 and D3 bytes. These bytes are combined together to form the
SDCC. Since each of these bytes represents a 64Kb/s message-based channel, the SDCC
represents a 192Kb/s data channel.
SDCC channels need to be terminated via a provisioning session at each ONS 15454 node in the
ring before messages can flow between nodes. After the SDCC channels have been terminated,
OAM&P will start up automatically within each ONS 15454 node. If there are two ONS 15454
nodes connected by multiple OC-N spans, the SDCC on each of these spans does not have to be
terminated at each node to start the flow of OAM&P information. You only need to terminate the
SDCCs on the ports of the OC-N cards that are going to serve as the OC-N trunk ports for the
ring. SDCCs that are not terminated are available for DCC tunneling.
A SONET link that carries payload from an ONS 15454 node to a third-party’s SONET node will
also have an SDCC defined in the Section Overhead. However, OAM&P messages will not be
recognized by the third-party’s node, and the SDCC should not be enabled. Disabling the SDCC
will not have any affect on the DS3, DS1, and other payload signals carried between nodes.
third-party equipment across ONS 15454 networks.
The SDCC is defined in the first STS-1 of an STS-N frame. Looking at the Section Overhead in
Table 2-4 you will find the D1, D2 and D3 bytes. These bytes are combined together to form the
SDCC. Since each of these bytes represents a 64Kb/s message-based channel, the SDCC
represents a 192Kb/s data channel.
SDCC channels need to be terminated via a provisioning session at each ONS 15454 node in the
ring before messages can flow between nodes. After the SDCC channels have been terminated,
OAM&P will start up automatically within each ONS 15454 node. If there are two ONS 15454
nodes connected by multiple OC-N spans, the SDCC on each of these spans does not have to be
terminated at each node to start the flow of OAM&P information. You only need to terminate the
SDCCs on the ports of the OC-N cards that are going to serve as the OC-N trunk ports for the
ring. SDCCs that are not terminated are available for DCC tunneling.
A SONET link that carries payload from an ONS 15454 node to a third-party’s SONET node will
also have an SDCC defined in the Section Overhead. However, OAM&P messages will not be
recognized by the third-party’s node, and the SDCC should not be enabled. Disabling the SDCC
will not have any affect on the DS3, DS1, and other payload signals carried between nodes.
DCC Tunneling
Starting in System Release 4.0, each Cisco ONS 15454 can have up to 84 DCC tunnel
connections. Previous system releases can support up to 32 DCC tunnel connections.
Terminated SDCCs used by the ONS 15454 cannot be used as a DCC tunnel end-point, and a
SDCC that is used as an DCC tunnel end-point cannot be terminated. All DCC tunnel
connections are bi-directional.
Terminated SDCCs used by the ONS 15454 cannot be used as a DCC tunnel end-point, and a
SDCC that is used as an DCC tunnel end-point cannot be terminated. All DCC tunnel
connections are bi-directional.
DCC Termination Guidelines
The following guidelines govern the provisioning of SDCC terminations:
Each ONS 15454 can have up to 84 DCC tunnel connections.
Each ONS 15454 can have up to 10 SDCC terminations.
Line DCCs and the Section DCC (when not used as a DCC termination by the ONS
15454) can be provisioned as DCC tunnels.
A SDCC that is used as a DCC tunnel end-point cannot be terminated.
All DCC tunnel connections are bi-directional.
Cisco recommends using Line DCCs to tunnel DCCs from third-party equipment across ONS
15454 networks. Looking at the Line Overhead in Table 2-4 there are 3 DCC channels, D4-D5-
D6, D7-D8-D9, and D10-D11-D12. In the North American SONET standard, these 192Kb/s
message-based channels are unassigned. Therefore, an ONS 15454 node can use these
channels to support up to 3 DCC tunnels. A forth tunnel can be created if necessary when the
ONS 15454 management SDCC termination is disabled.
Third-party SONET equipment may be connected end-to-end through any network consisting of
ONS 15454 nodes. The SONET payload can be connected in the standard way. The third-party
SONET equipment SDCC channels may be connected together via Line DCC tunnels, when the
SDCC is not used for ONS 15454 DCC terminations. This means the third-party SONET
equipment OAM&P will operate through the DCC tunnel as if the third-party SONET equipment
were directly connected together with fiber.