user manual

10-11
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 10 Circuits and Tunnels
10.4.2 IP-Encapsulated Tunnels
Note A DCC does not function on a mixed network of ONS 15454 SDH nodes and ONS 15454 nodes. DCC
tunneling is required for ONS 15454 SDH nodes transporting data through ONS 15454 nodes.
Figure 10-3 Traditional DCC Tunnel
When you create DCC tunnels, keep the following guidelines in mind:
• Each ONS 15454 SDH can have up to 84 DCC tunnel connections.
• Each ONS 15454 SDH can have up to 84 regenerator SDCC terminations.
• A regenerator SDCC that is terminated cannot be used as a DCC tunnel endpoint.
• A regenerator SDCC that is used as a DCC tunnel endpoint cannot be terminated.
• All DCC tunnel connections are bidirectional.
Note A multiplex SDCC cannot be used for tunneling if a data DCC is assigned.
10.4.2 IP-Encapsulated Tunnels
An IP-encapsulated tunnel puts an SDCC in an IP packet at a source node and dynamically routes the
packet to a destination node. A traditional DCC tunnel is configured as one dedicated path across a
network and does not provide a failure recovery mechanism if the path is down. An IP-encapsulated
tunnel is a virtual path, which adds protection when traffic travels between different networks.
IP-encapsulated tunneling has the potential of flooding the DCC network with traffic resulting in a
degradation of performance for CTC. The data originating from an IP tunnel can be throttled to a
user-specified rate, which is a percentage of the total SDCC bandwidth.
Each ONS 15454 SDH supports up to ten IP-encapsulated tunnels. You can convert a traditional DCC
tunnel to an IP-encapsulated tunnel or an IP-encapsulated tunnel to a traditional DCC tunnel. Only
tunnels in the DISCOVERED status can be converted.
Caution Converting from one tunnel type to the other is service-affecting.
Third party
equipment
Link 1
From (A)
Slot 3 (STM-1)
Port 1, RSDCC
To (B)
Slot 13 (STM-16)
Port 1, Tunnel 1
Node 1
71676
Third party
equipment
Link 2
From (A)
Slot 12 (STM-16)
Port 1, Tunnel 1
To (B)
Slot 13 (STM-16)
Port 1, Tunnel 1
Node 2
Link 3
From (A)
Slot 12 (STM-16)
Port 1, Tunnel 1
To (B)
Slot 3 (STM-1)
Port 1, RSDCC
Node 3