Cisco Systems MGX 8220 manual Frame-Relay-to ATM Service Interworking SIW, PVC Status Management

Chapter

Frame Relay Service Modules (FRSMs)

PVC Status Management

The management of the ATM layer and FR PVC Status Management can operate independently. The PVC status from the ATM layer will be used when determining the status of the FR PVC. However, no direct actions of mapping LMI A bit to OAM AIS will be performed.

Frame-Relay-to ATM Service Interworking (SIW)

By specifying “service interworking” as the channel type when adding a Frame Relay PVC to an FRSM, all PVC data is subject to service interworking translation and mapping in both the Frame Relay–to–ATM and ATM–to–Frame Relay directions.

Figure 4-2shows a BPX 8620 network with service interworking connections.

Figure 4-2 BPX Network with Service Interworking Connections

T1 or E1

ATM FUNI CPE

ATM UNI CPE

T1 or E1

FRSM

AUSM

	BPX 8620 network
MGX
	PVCs
8220

BPX 8620

A

S

I

T3, E3, OC3

ATM-UNI CPE

MGX 8220

FRSM

H8268

FR UNI

CPE

Figure 4-2shows an MGX 8220 unit and an FRSM to the right with three Frame Relay connection endpoints. These connections indicate the Frame Relay ends of service interworking connections. The diagram shows some possibilities for terminating the other ends of the connections.

•ATM FUNI (Framed UNI) port on an FRSM

•ATM UNI port on an AUSM

•ATM UNI port on a BPX 8620 ASI card

The service interworking is full Frame Relay Forum (FRF.8) compliant and provides full support for routed and bridged PDUs, transparent and translation modes, and VP translation.

Cell Loss Priority and Congestion Indication

In addition to frame-to-cell and DLCI to VPI/VCI conversion, the service interworking feature maps cell loss priority and congestion information between the Frame Relay and ATM formats. The CLP and congestion parameters can be modified for individual connections with the cnfchanmap command.

	Cisco MGX 8220 Installation and Configuration
4-4	Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003