T320 Internet Router
| The T320 Internet router (see Figure 3.13) has a maximum aggregate throughput of 160 Gbps, full duplex. It utilizes the latest ASIC architecture to support high-bandwidth interfaces. It accepts up to eight FPCs and offers a high level of redundancy so that no single point of failure can cause the entire system to fail. Figure 3.13. T320 Internet Router Chassis and Components Table 3.8 shows the physical specifications of the T320 Internet router, and Table 3.9 gives an overview of the major hardware components of the router. Table 3.8. T320 Internet Router Physical Specifications
Table 3.9. T320 Internet Router Major Hardware Components
The chassis includes two front support posts to attach the router to a front-mount or four-post rack or a cabinet, two mounting ears for center-rack mounting, and two ESD points, one at the front and one at the rear. The midplane is located in the center of the chassis and forms the rear of the FPC card cage. The FPCs install into the midplane from the front of the chassis, and the SIBs, Routing Engines, CBs, and SCGs install into the midplane from the rear of the chassis. The power supplies and cooling system components also connect to the midplane. The Switch Interface Boards (SIBs) (see Figure 3.14) provide the switching function to the destination FPC. Three SIBs are installed in the rear of the chassis. The SIBs create the switch fabric for the router, providing up to 320 million packets per second (Mpps) of forwarding. Figure 3.14. T320 SIB The Flexible PIC Concentrators (FPCs) install vertically in the front of the chassis. The FPCs are numbered left to right from 0 through 7. Each FPC accepts up to two PICs. An FPC can be installed into any FPC slot on the router, regardless of which PICs it contains. Each FPC contains one Packet Forwarding Engine. The Packet Forwarding Engines receive incoming packets from the PICs installed on the FPC and forward them through the switch planes to the destination port. Each FPC contains data memory which is managed by the Queuing and Memory Interface ASICs on the board and a processor subsystem (PMB). Two LEDs located on the craft interface above the FPC display the status of the FPC. An FPC online/offline button, located between the LEDs, is used to take the FPC offline and bring it online. FPCs are hot-removable and hot-insertable. When you bring an FPC online, the Routing Engine downloads the FPC software, the FPC runs its diagnostics, and the PICs in the FPC are enabled. No interruption occurs to the routing functions. Figure 3.15. T320 FPCs The T320 router supports two types of FPC: FPC2, rated at 10 Gbps full duplex, which supports PICs also used in the M160 router, and FPC3, rated at 20 Gbps full duplex, which supports higher-speed PICs. The router can operate with any combination of FPC2s and FPC3s installed. The installation and removal of the two FPC types is identical. The two types of FPC can be visually distinguished by the ejectors on the PICs installed in the FPC. PICs compatible with an FPC3 have a plastic ejector handle at the top of their faceplate, and PICs compatible with an FPC2 have captive screws at the top and bottom of their faceplate. In this guide, both types are referred to simply as "FPC" except where the differences between the two are discussed. The T320 router can have one or two host subsystems, which provide the routing and system management functions of the router. Each host subsystem consists of a Routing Engine and a Control Board (CB) installed in adjacent slots. Each host subsystem functions as a unit; the Routing Engine requires the corresponding CB to operate, and vice versa. Each host subsystem has three LEDs, located on the craft interface, that display its status.
The T320 router can have one or two Routing Engines. The Routing Engines install into the upper rear of the chassis. If two Routing Engines are installed, one functions as master and the other as backup. If the master Routing Engine fails or is removed, the backup restarts and becomes master. The Routing Engines are hot-pluggable. The LEDs that report Routing Engine status are located on the craft interface, rather than on the Routing Engine faceplate. Each CB works with its adjacent Routing Engine to provide control and monitoring functions for the router (see Figure 3.16). These include determining Routing Engine mastership, controlling power, reset and SONET clocking for the other router components, monitoring and controlling fan speed, and monitoring system status. Figure 3.16. T320 CB The CBs install into the upper rear of the chassis. If two CBs are installed, one functions as master and the other as backup. If the master CB fails or is removed, the backup restarts and becomes master. The CBs are hot-pluggable. Each CB contains an Ethernet switch for intermodule communication; a bus to the Routing Engines; a processor subsystem (the SPMB); and three LEDs, located on the CB faceplate, that display the status of the CB.
The router has two SONET Clock Generators (SCGs). The SCGs provide the clock signal for the SONET/SDH interfaces on the router (see Figure 3.17). They can also select a clock signal from any FPC or from the external clock inputs. The SCGs install into the upper rear of the chassis. The SCGs are hot-pluggable. Each SCG contains a 19.44-MHz Stratum 3 clock; two external clock inputs; and three LEDs, located on the SCG faceplate, that display the status of the SCG. Figure 3.17. T320 SCG
The craft interface (see Figure 3.18) allows you to view status and troubleshooting information at a glance and to perform many system control functions. The craft interface is located on the front of the router above the FPCs and contains alarm LEDs, a lamp test button, an LCD display, LEDs for the host subsystems, SIBs, FPCs, and FPC online/offline buttons .The craft interface is hot-insertable and hot-removable. Figure 3.18. T320 Craft Interface The Connector Interface Panel (CIP), located at the left side of the FPC card cage, consists of Ethernet, console, and auxiliary connectors for the Routing Engine ports, and alarm relay contacts (see Figure 3.19). The front electrostatic discharge point is located near the bottom of the CIP. The CIP is hot-pluggable. Figure 3.19. T320 CIP The router has two load-sharing DC power supplies, located at the lower rear of the chassis. The power supplies connect to the midplane, which distributes the output voltages produced by the power supplies to the router components, depending on their voltage requirements (see Table 3.10). Each power supply has two inputs, each with its own 80-A circuit breaker and each requiring a dedicated DC power source. The power supplies are redundant. If one power supply fails or is removed, the second power supply instantly assumes the entire electrical load and can provide full power for as long as the router is operational. Power supplies are hot-removable and hot-insertable. The router supports DC power only. Each power supply is cooled by its own internal cooling system. Table 3.10. T320 Power Supply Electrical Specifications
The router cooling system consists of two front fan trays, one rear fan tray, front and rear air filters, and an air filter on each power supply. The cooling system components work together to keep all router components within the acceptable temperature range. All fan trays and filters are hot-insertable and hot-removable. The two front fan trays are interchangeable. The front and rear fan trays are not interchangeable. The host subsystem monitors the temperature of the router components. When the router is operating normally, the fans function at lower than full speed. If a fan fails, the speed of the remaining fans is automatically adjusted to keep the temperature within the acceptable range. Figure 3.20 shows the air flow through the router and the location of the cooling system components. Figure 3.20. Air Flow through the T320 Chassis The router's cable management system consists of a row of nine semicircular plastic bobbins mounted on the front of the router below the FPC card cage. The PIC cables wrap around the bobbins, keeping the cables organized and securely in place. The curvature of the bobbins also helps maintain the proper bend radius for optical PIC cables. The router has LEDs that display the status of various router components. Table 3.11 lists the LEDs on the craft interface and the individual router components. Table 3.11. T320 Internet Router LEDs
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Pages: 185