Cisco Systems RJ-45-to-AUX manual Phoenix Asic, Cisco Express Forwarding Asic components

Figure 4.3: Cisco Express Forwarding ASIC components.

Note CEF supports Ethernet, Fiber Distributed Data Interface (FDDI), Point−to−Point Protocol (PPP), High−Level Data Link Control (HDLC), Asynchronous Transfer Mode (ATM)/AAL5snap, ATM/AAL5mux, ATM/AAL5nlpid, and tunnels.

Phoenix ASIC

The Phoenix ASIC is another ASIC used to handle high−speed data traffic on the Supervisor Engine III. This ASIC provides a gigabit bridge between each of the buses located on the module. The Phoenix ASIC has a 384K buffer used to handle traffic between buses located on the module. From the perspective of the EARL and the SAMBA, the Phoenix ASIC appears as another port on the box. Figure 4.4 depicts the Phoenix ASIC.

Figure 4.4: The Phoenix ASIC used on the Supervisor Engine III.

It is important to note that some line modules do not have access to all three buses. In the case of the Catalyst 5500 13−slot chassis, slots 1 through 5 are connected to bus A, slots 1 through 9 are connected to bus B, and slots 1 through 5 and 10 through 12 are connected to bus C. The placement of line modules in the chassis becomes important. You will learn more about this topic in Chapter 6.

LCP

The LCP is located on each line module. It is the responsibility of the LCP to provide communications for the MCP located on the Supervisor Engine.

SAGE ASIC

The Synergy Advanced Gate−Array Engine (SAGE) ASIC performs the same functions as the SAINT. This ASIC also has some additional functions, such as gaining access to the token in FDDI or Token Ring networks. Processing performed by SAGE takes place in the hardware ASICs, requires no CPU cycles, and adds no additional latency to the switching process.

QTP ASIC

The architecture of the Catalyst 3900 is centered around the AXIS bus (discussed earlier), using the Quad Token Ring Port (QTP) ASIC. Cisco uses the 3900 series line of switches as its primary switch dedicated to Token Ring topology networks. This line of switches uses a 520Mbps switching fabric through which all switched interfaces communicate. The ASIC interfaces directly with the Quad Media Access Controller (QMAC) ASIC and provides the necessary functions for switching directly between the four Token Ring ports

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