Cisco Systems 8600 Series manual Signaling Plane, UNI Signaling Channel

Signaling Plane

Signaling Plane

To support ATM and Frame Relay SVCs, the BPX switches essentially overlay a signaling network over a traditional (that is PVC-based) network. This signaling network, indicated by the dashed lines in Figure 8-2,connects all of the BPX switches with ESP and extends to the CPE. The signaling plane establishes and maintains SVCs between the CPE, that is, end users, across a Cisco StrataCom wide-area ATM network.

Figure 8-2 BPX Switch with ESP Network Signaling Plane

CPE

CPE

Signaling

End-user data

Signaling

End-user data

WAN	WAN
Service	Service
Node	Node

WAN	WAN
Service	Service
Node	Node

WAN switching network

Signaling

End-user data

Signaling

End-user data

CPE

CPE

S6358

The signaling plane is created out of two basic types of signaling channels:

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User to Network Interface (UNI) signaling channels.

Network to Network Interface (NNI) signaling channels.

The signaling VCCs are normally configured during the provisioning of UNI ports and NNI trunks.

UNI Signaling Channel

There is an internal signaling VCC established between every UNI port on the BPX switch which will support ATM or Frame Relay SVCs and the ESP in the BPX switch.There are two types of UNI signaling channels supported by the BPX switch as shown in Figure 8-3.

•ATM UNI—For ATM CPE, these UNI VCCs extend from an ATM UNI port to the ESP. This is either a one segment cross-connect between the BXM (or ASI) attached to the ATM CPE and the BXM attached to the ESP within the BPX switch, or a two segment VCC from the MGX 8220 AUSM port connected to ATM CPE and the BXM attached to the ESP within the BPX switch. (Note that VPI 0 and VCI 5 are reserved on the ATM UNI port for ATM SVC signaling channels. The ILMI signaling channel will use VPI 0 and VCI 16, and the PNNI signaling channel will use VPI 0 and VCI 18.)

•Frame Relay UNI—For Frame Relay CPE, there will always be a two segment VCC between the MGX 8220 FRSM port connected to the ATM CPE and the BXM attached to the ESP within the BPX switch. (Note that DLCI 0 is reserved on the Frame Relay UNI port for Frame Relay SVC signaling channels.)

ATM and Frame Relay SVCs, and SPVCs 8-5