Filter
Top Products
4-4
Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
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 4-2 shows a BPX 8620 network with service interworking connections.
Figure 4-2 BPX Network with Service Interworking Connections
Figure 4-2 shows 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.
MGX
8220
FRSM
FRSM
BPX 8620
AUSM
A
S
I
FR UNI
CPE
T1 or E1
T1 or E1
T3, E3, OC3
ATM-UNI CPE
ATM FUNI CPE
ATM UNI CPE
BPX 8620 network
PVCs
H8268
MGX
8220