Intel NETWORK PROCESSOR IXP2800 - Manual (Page 295)

Hardware Reference Manual 295
Intel
®
IXP2800 Network Processor
Media and Switch Fabric Interface
8.9.1.3 Dual Network Processor Full Duplex Configuration
In the dual Network Processor, full duplex configuration, an ingress Network Processor and an
egress Network Processor are integrated to offer a single full duplex interface to a fabric, similar to
the CSIX-L1 interface, as shown in Figure 104 . This configuration provides an interface that is
closest to the standard CSIX-L1 interface. It is easiest to bridge between this configuration and an
actual CSIX-L1 interface.
Flow control CFrames are forwarded by the egress Network Processor to the ingress Network
Processor over a separate flow control interface. The bandwidth of this interface is a quarter of the
primary interface offered to the fabric. A signal from ingress Network Processor to egress Network
Processor provides flow control for this interface. (This interface is the same interface that was
used in the hybrid simplex configuration.) A separate signal from egress Network Processor to
ingress Network Processor provides the state of the CSIX-L1 “ready bits” that were received from
the fabric, conveying the state of the fabric receiver, and those that should be sent to the fabric,
conveying the state of the egress Network Processor receiver.
The PCI may be used to convey additional information between the egress Network Processor and
ingress Network Processor.
Figure 104. Dual Network Processor, Full Duplex Configuration
B2737-02
Transmitter
Receiver
Receiver
Transmitter
PCI
Serial CSIX Ready Bits
Flow Control
CSIX Flow Control CFramers
Fabric
Interface
Chip
Ingress
Network
Processor
Egress
Network
Processor