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  1. #31
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    Chapter Two

    Cisco Router Hardware

    The Cisco router product line has three flavors. Cisco routers are available as modular, fixed or combination configurations. Along with full router configuration Cisco offers router platforms on personal computer (PC) card format. Additionally, Cisco combines routers and small hubs into one device suitable for small office installations. Key to a successful implementation of Cisco routers in a networking environment is proper placement and configuration of the router. Each Cisco router offering is suited for a specific function. These functions are depicted in Figure 2.1 as core, distribution and access. These functional characteristics make up Cisco’s router internetwork architecture.
    1. Cisco Router Network Architecture Early on in the development of internetworks, an architecture emerged. This architecture for deploying routers was documented into an architecture which Cisco employs and preaches to its customer base. The architecture relies on the ability of the processor in the router and its need for processing routes, filters and physical connections. The architecture places the larger Cisco 7x00 series and 12000 series routers at the center or core of the network. The 4x00 series routers are at the net layer of the network architecture called the distribution layer. Finally, the 25xx, 100x, 7x0 and 200 series routers constitute the access layer of the architecture. While these assignments to the three different layers of the architecture make sense it does not mean that 7x00 series routers can not be used as a distribution or access router. Likewise, in some cases the 4500 and 4700 series router platforms may be used as a core or access router. However, the smaller fixed and combination routers are most suited for the access layer and will not perform the physical or logical requirements of the core or distribution routers.
      1. Core The routers that comprise the core layer of the architecture are often referred to as the backbone routers. These routers connect to other core routers providing multiple paths over the backbone between destinations. These routers carry the bulk of WAN traffic between the distribution routers. Core routers are usually configured with several high speed interfaces as shown in Figure 2.2. However, the introduction of ATM and interface cards providing up to OC-12 speeds (622Mbps), core routers may only require two physical interfaces. However, as the section on ATM configuration will reveal, multiple subinterfaces are allowed on each physical interface. The need for the core router to manage many high speed interfaces is still a requirement even with only two physical ATM interfaces.
        The use of Packet over SONET is another alternative to proving a high-spped core using Cisco routers. In large WANs and MANs it is common to have the backbone built on SONET rings with OC-3, OC-12 and OC-48 connections. Packet over SONET allows for the transmission of IP direct over the SONET network without the use of ATM. This provides a great incentive to corporations that have yet to embrace ATM but have a need for high speed and bandwidth over their backbone. Using Packet over SONET as the backbone transport requires an investment in only routers versus ATM which requires investments in routers and switches.
      2. Distribution The distribution router functions as the main conduit for a location back to the core. As an example, in Figure 2.3, the distribution router acts as a core router for a campus environment but as a distribution router for a building. Or the distribution router may act solely as a distribution router for a region or campus managing only the transmission of data between the core and the access layers.
      3. Access
      The outer layer of the architecture is the access layer. It is at this layer that end users gain access to the network resources connected by the routers. A typical example for using access routers is in large buildings or campuses. As depicted in Figure 2.4, access routers connect workgroups and/or floor segments within a building to the distribution router. Access routers also provide remote dial-up connectivity for temporary connections.



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  2. #32
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    1. Online Insertion and Removal (OIR)
    2. Many networks require 24x7 up time. Powering down a router to replace or add new interface cards causes an outage to all the LAN segments and WAN connections. Cisco IOS along with the hardware has implemented a technique to avoid unnecessary downtime called Online Insertion and Removal (OIR).
    3. Supported Platforms OIR is specific to the high-end router platforms. The Cisco 7000, 7200, 7500 and 12000 series routers all support the OIR feature. The OIR feature works with all interface processor boards allowing the router power and non-affected interface cards to remain online and functional.
    4. OIR Process Removal of an interface processor board is accomplished at anytime. A new interface processor board is installed in the now available slot and the route processor will recognize that a new board has been installed. If the newly installed board is a higher density or replacement board with equivalent interfaces (i.e., Ethernet), the processor board recognizes that the boards are similar in function and automatically configures the interfaces as to reflect the previous board’s configuration. In this way, OIR reduces operator intervention thereby eliminating configuration input errors on the new interface processor board.
    5. Exceptions to using OIR
    6. OIR is specific to interface processors for all interface types. OIR does not support the dynamic replacement of a route processor, route switch processor, or a network engine processor. Replacing these boards requires that the router be powered off. However, if you are using the 7507 or 7513 series routers and have taken advantage of the High System Availability (HSA) feature with Route Switch Processors 2 or 4 (RSP2 or RSP4) removes this restriction. HSA enables these router platforms to operate with two RSP boards. By default the RSP installed in the first RSP slot is the system master and the second RSP slot is the system slave. Using HSA it is now possible to remove an RSP for upgrading or for replacement without disrupting the power to the router or interrupting processing the interface processors.
    7. Cisco 12000 Series
    The 12000 series router platform is built in support of providing gigabit (Gb) speeds across WAN and MAN backbones. The Cisco 12000 series is targeted at scaling Internet and enterprise backbones at speeds up to 2.4 Gbps. This is the aggregate bandwidth of an OC-48 SONET connection. The Cisco 12000 series is optimized for IP only networks and thereby provides a high-speed backbone infrastructure for IP based networks. The ability to handle OC-3 through OC-48 SONET connections enables network engineers to expand the backbone switching capacity with a range from 5 to 60 Gbps. Since the 12000 eries is built for providing core backbone it is designed for maximum uptime and minimal disruption. These features are found in the its architeture for:
      • Redundant switch fabric design
      • Line card redundancy
      • Dual Gigabit Route Processors
      • Online software configuration
    The speeds of the Cisco 12000 series routers is possible from the synchronized circuitry of two cards. The Clock and scheduler card (CSC) and the Switch Fabric Card (SFC). Both the CSC and SFC provide an OC-12 switching bandwidth between the line cards for the system. Each type of card has a switching capacity of 15 Gbps.
    A minimum of one CSC is required in the router. The CSC performs the following functions for the router:
      • System Clock - clicking sent to all line cards, GRP and SFCs. It synchronizes data transfer between the various components of the system. In redundant mode the CSC clocks are synchronized for fail over.
      • Schedule - The scheduler function handles requests form the line cards and schedules when the line card can have access to the switch fabric.
    The Switch Fabric Card provides the following functionality for the router:
      • Contains only switching fabric.
      • Carries traffic between line cards and GRP.
      • Receives scheduling and clocking form the CSC.
    The chassis configuration of the Cisco 12000 router comes with an upper cage and lower cage. The upper cage is used mostly for the line cards to connect to the network in addition to the Gigabit Route Processor (GRP) card. The lower cage supplements the ability for the 12000 series router to perform switching by having extra slots for the SFC installs. For more information on the specific cage configurations of the 12000 series router consult the section specific to the model.


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  3. #33
    عضو فعال

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    The 12000 series comes in three models. These are the 12004, 12008 and 12012.
        1. Cisco 12004 Series The Cisco 12004 series is the smallest of the 12000 line. It provides a total of four interface slots and two slots for Gigabit Router Processors. The 12004 supports all the available interfaces of the 12000 series. The 12004 is usually used in IP SONET backbone networks with minimal connectivity requirements. Typically the 12004 is used for OC-3 and OC-12 interface connections. The 12004 has an IP datagram switching capacity of 5 Gbps. In a single CSC configuration the 12004 supports OC-12 data rates and a 1.25 Gbps switching capacity. Using redundant CSCs in the two center slots of the upper cage and three SFCs in the lower cage the 12004 can support OC-48 data rates with a switching capacity of 5 Gbps. In a redundant GRP configuration the 12004 has two line card slots available for network connectivity.
        2. Cisco 12008 Series (picture h7689.gif 7691.gif 7690.gif) The Cisco 12008 can switch IP data grams in the range of 10-40 Gbps. Minimal configuration requirement for the Cisco 12008 are the presence of a single GRP and a single Clock and scheduler card (CSC). As shown in Figure 2.5 the CSC must be placed in either of the two center slots in the upper cage of the 12008. A second CSC may be placed in the open CSC slot for redundancy. The GRP may be placed in any of the remaining slots. A second GRP may be installed for redundancy in any of the remaining slots. Using redundant GRPs leaves 6 available slots for line card connectivity to the network. The lower cage houses the three optional slots for used by SFCs.
          Installation of a second CSC does not increase the switching capacity but provides redundancy. The addition of the three SFCs enables the router to move from an OC-12 with a switching capacity of 10 Gbps to support of an OC-48 data rate with switching capacity to 40 Gbps with full redundancy should either CSC fail or a single SFC fail.
        3. Cisco 12012 Series (h11017 h10476) The Cisco 12012 has the capacity to switch IP datagrams anywhere from 15 to 60 Gbps. The increase in interface density of the 12012 is created by expanding the lower cage. The lower cage of the 12012 contains five keyed slots for placing the CSC in slots 0 or 1 and the SFCs in slots 2-4. The GRP is still installed in the upper cage. In a redundant GRP configuration there are 10 open line card slots for network connections. The single CSC configuration supports OC-12 data rate and a capacity of 15 Gbps switching. A redundant CSC configuration with three SFCs installed enable the 12012 to support OC-48 data rates and a switching capacity of 60 Gbps.
        4. Usage
    The 12000 series is placed at the very core of the network. Since it is optimized for IP traffic it must be designed that IP traffic only flows through these routers. For example, in a network that is based on IP and SNA the SNA data must be transported using RSRB or DLSw+ with TCP or FST encapsulation techniques. In this manner, the high speed backbone can be used for connecting remote locations to the main data centers. Likewise, using Voice over IP the router or PBX must encapsulate the voice data into IP prior to delivering it to the 12000 series backbone routers. Based on this type of usage the 12000 series is ideal for:
      • Internet service providers (ISPs)
      • Carriers providing Internet services and utilities
      • Competitive access providers (CAPs)
      • Enterprise wide-area network (WAN) backbones
      • Metropolitan-area network (MAN) backbones

        1. Switch Processors (h10547 h10548 The Cisco 12000 Gigabit Route Processor is based on the IDT R5000 Reduced Instruction St Computer (RISC) CPU. This processor has an external bus clock speed of 100MHz and an internal clock speed of 200 MHz. All the models of the Cisco 12000 series routers use the same GRP card. The GRP may be installed in any slot of the 12012 except for the far right slot. This is reserved for the alarm card. Normal practice is to install the first GRP in the far left slot. On the 12008 the GRP may be installed in any availabel slot of the upper cage except for the two center slots. These are reserved for the Clock and Scheduler Cards.
        2. Memory Each GRP comes with a base of 64 MB of dynamic random-access memory (DRAM) which is upgradeable to 256MB of parity-protected extended data output (EDO) DRAM. The DRAM is provided in two dual in-line memory module (DIMM) format running at 60 nanoseconds (ns). The GRP uses the DRAM for storing systems software (Cisco IOS), configuration files, and line card routing tables. The Cisco IOS runs from DRAM. Table 2.x lists the DRAM socket locations and DRAM configuariotns for upgrading from 64 MB to 256MB.



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  4. #34

  5. #35
    عضو فعال

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    (هذا عبارة عن جدول ما رضي يزبط معي رتبه بمعرفتك)
    Total DRAM
    64 MB
    128 MB
    128 MB
    256 MB

    DRAM Socket
    U39 (bank 1)
    U39 (bank 1) and U42 (bank 2)
    U39 (bank 1)
    U39 (bank 1) and U42 (bank 2)


    Number of DIMMs
    1 (64 MB DIMM)
    2 (64 MB DIMM)
    1 (128 MB DIMM)
    2 (128 MB DIMM)


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  6. #36
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    1. Table 2.x: DRAM update configurations.
    2. In addition to DRAM the GRP also includes Static RAM (SRAM) and Non-volatile RAM (NVRAM). The SRAM provides 512KB of secondary CPU cache memory functions. The SRAM can not be configured by the user nor can it be upgraded in the field. The SRAM is primarily a staging area for routing table updates to and from the line cards. The NVRAM stores router configurations, system cache information and read only memory (ROM) monitor variables in 512 KB. Information stored in NVRAM is available even after the router loses power. SRAM and DRAM lose the information stored within them. Like SRAM the NVRAM can not be configured by the user nor can it be upgraded.
    3. The GRP also utilizes flash memory. There is 8 MB of single inline memory modules (SIMM) on the GRP for storing Cisco IOS software images as well as saving router configurations and other type of end user files. Additionally, the only board flash memory can be coupled with the ability to use 20 MB PCMCIA flash memory cards that install on two slots on the GRP with a total capacity of 40 MB. Each card can be used for storing Cisco IOS software images and other files required by the router for operation.
    4. For operational support the GRP enables remote access to the Cisco 12000 router through either an auxiliary dial-up port in an IEEE 802.3 10/100 Mbps Ethernet port for Telnet connections. In addition the GRP has an RS-232 console port connection for direct serial connectivity form a PC to the router.
    5. The GRP can be installed in any of the slots available in the upper cage of the Cisco 12000 series routers. The exception to this is the Cisco 12012 where the GRP can not be installed in the far right slot. This slot is reserved for the alarm card.
    6. Line Cards
    Each line card is comprised of several functions equivalent on each card. The line card uses for burst buffers to prevent packet dropping when there is an instantaneous increase in back-to-back small packets queued for transmission. Burst buffers increase throughput and maintain an even packet burst for packets arriving on Layer 3 switch processing.
    Each line card contains two silicon queuing engines one for receive and one for transmit. The receiving engine moves packets form burst buffers to the switch fabric. The transmit moves the packets from the switch fabric to the transmit interface. The silicon engines also manages the movement of IP packets in buffer memory. Buffer memory defaults to 32 MB split evenly between receive and transmit buffers. The amount of buffer memory in use is configurable up to 64 MB for receive and 64 MB for transmit.
    An application-specific integrated circuit (ASIC) is used for supporting the high-speed process required to perform layer 2 switching. To assist in the decision making an IDT R5000 200 MHz RISC processor is on the line card to make forwarding decisions based on the Cisco Express Forwarding table and the Layer 2 and Layer 3 information in the packet. The GRP is constantly updating the table based on information gathered from the routing table.
    The line card also contains a switch fabric interface. This is the same 1.25 Gbps full-duplex data path used by the GRP. When a packet is on the proper queue the switch fabric requests the CSC for scheduling the transfer of the packet across the switching fabric.


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  7. #37
    عضو فعال

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    There is also a maintenance bus module on the line card that provides the master Mbus module of the GRP with requested information. The type of information reported in temperature, and voltage. In addition the Mbus on the line card stores the serial number, hardware revision level and other pertinent information about the card in EEPROM.
    In addition each line card maintains the Cisco Express Forwarding (CEF) table. The table is built on routing table information provided by the GRP and is used to make forwarding decisions.
    There are six available line cards for connecting the 12000 series router to the network. These are:
      • Quad OC-3c/STM-1c Packet-Over-SONET (POS) (h10781.gif)
      • Quad OC-3 ATM Line Card
      • OC-12c/STM-4c Packet-Over-SONET (POS)
      • OC-12c/STM-4c Asynchronous Transfer Mode (ATM)
      • OC-48c/STM 16 Optical IP Interface Card
      • Channelized OC-12 Line Card
    The Quad OC-3c/STM-1c Packet-Over-SONET (POS) is shown in Figure 2.6
    . The card has four ports for interfacing directly to the SONET providers equipment. The Quad OC-3c/STM-1c Packet-Over-SONET (POS) line card must be ordered for either single mode or multimode SC fiber connection. Each mode supports full-duplex transmission. The card uses for 128 KB burst buffers to prevent packet dropping when there is an instantaneous increase in back-to-back small packets queued for transmission.
    The Quad OC-3 ATM Line Card shown in Figure 2.7 (h10781) performs ATM segmentation and Reassembly functions for ATM connectivity. Segmentation is the process of converting packets to ATM cells. Reassembly is the process of converting ATM cells to packets. The Quad OC-3 ATM Line Card can handle up to 4000 simultaneous reassemblies of an average packet size of 280 bytes. To perform this ability the Segmentation and Reassembly is performed on ASIC. The ASICs also allow each of the four ports on the Quad OC-3 ATM Line Card to support 2000 active virtual circuits. The card must be ordered as either single mode or multimode fiber connection. The Quad OC-3 ATM Line Card supports a burst buffer of 4 MB.
    The OC-12c/STM-4c Packet-Over-SONET (POS) illustrated in Figure 2.8 (h10782.gif) has a one duplex SC single- or multimode fiber connection. The port supports OC-12c at 622 Mbps data rate. The OC-12c/STM-4c Packet-Over-SONET (POS) has a burst buffer of 512 KB.
    The OC-48c/STM 16 Optical IP Interface Card shown in Figure 2.9 (15424.gif) a single duplex SC or FC single mode fiber connection. The top port is the transmit (TX) connection and the bottom port is the receive (RX) connection. The interface supports a full 2.5 Gbps optimized for transporting packet over SONET (POS). The burst buffer on the OC-48c/STM-16 Optical Interface Card is 512 KB with a default buffer memory of 32 MB for receive and 32 MB for transmit. Cisco IOS software Release 11.2(14)GS1 and line card microcode Version 1.14 is required for complete support of all features. The typical maximum distance the line card can sustain is 1.2miles or 2 kilometers.
    The Channelized OC-12 Line Card shown in Figure 2.10 (11704.gif) supports only single mode full-duplex SC connections at 622 Mbps. Its burst buffer size is 512 KB. The forwarding processor on the Channelized OC-12 Line Card is an IDT R5000 RISC processor rated a 250 MHz.
        1. Software Support
    The Cisco IOS software for the Cisco 12000 series routers is optimized for transporting IP traffic. The first release of Cisco IOS supporting the Cisco 12000 series platform is the 11.2 release. The Cisco IOS Release 11.2 supports the following IP IOS functions:
      • Routing Protocols
    Interior: RIP, OSPF, IS-IS, ISO/CLNP, EIGRP, EGP
    Exterior: BGP
      • Routed Protocols
    TCP/IP, UDP/IP
      • BGP4 Support
    Route Reflections
    MED (Multi-Exit Discriminators)
    Communities
    DPA (Destination Preference Attribute)
    Flat/Weighted Route Dampening
    Confederations
    Next Hop-Self
    GP Multipath
    Static Routing (IGP)
      • Management
    SNMP, Telnet, MIB II


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  8. #38
    عضو فعال

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    Cisco 7500 Series The Cisco 7500 series router is the high-end routing platform for supporting corporate enterprise wide networks as well as a keystone for the Internet backbone itself. The port capacity and available interface types enable the 7500 to serve all layers of Cisco’s routing architecture. The speed with which the 7500 series processes packets between the various interfaces is the use of high-speed bus architectures.. The architecture is called the Cisco Extended Bus (CyBus). The CyBus supports any combination of interface processors on the 7500 series platform. The CyBus ahs an aggregate throughput of 1.067Gbps. The 7500 series encompasses three models: Cisco 7505, Cisco 7507 and the high-end of the platform is Cisco 7513. Each model has a specific location for the RSP boards. The 7500 series platform supports fifteen different feature sets. These feature sets along with other characteristics of the 7500 series platform are found in Appendix B.
    1. Cisco 7505 Series The 7505 series is the smallest platform of the 7500 line. It supports four interface processors and one RSP board. Figure 2.11 depicts the platform format for the 7505. The 7505 comes with a single CyBus for attaching the interface boards to the RSP. The 7505 series supports RSP1 and RSP4. The single power supply offered on this platform makes the 7505 series a choice for locations with low availability requirements but with high throughput requirements and the need for varied interface support.
    2. Cisco 7507 Series The Cisco 7507 series router platform from Cisco expands the interface combination possibilities by providing five slots for interface processors as shown in Figure 2.12. The 7507 series provides a higher reliability through the use of a second power supply and dual RSP boards. The redundant configuration for the 7507 series enables it to reliably serve as a core or distribution router. The 7507 series uses either an RSP2 or RSP4. The RSPs used in a dual RSP configuration (HSA) should however be the same RSP platform. Added to the higher availability architecture of the 7507 is the use of a dual CyBus architecture. This architecture not only enables recovery should a bus fail, the architecture allows both buses to be used simultaneously allowing higher throughput than on the 7505 series.
    3. Cisco 7513 Series The Cisco 7513 is the high capacity 7500 series router platform from Cisco. This series provides two RSP slots for HSA and eleven interface processor slots, ash shown in Figure 2.13, to support any combination of network interface requirements. The 7513 series also supports the dual CyBus architecture and allows for two power supplies. Both RSP2 and RSP4 processors are supported on the platform. The 7513’s high capacity for interfaces makes it a useful platform for multiple LAN segment interfaces in a large environment along with using the interface combination possibilities to serve as a core, distribution or access router.
    4. Usage The 7500 series is quite versatile and provides the functionality of core, distribution and access layers. Figure 2.14 illustrates the various functions and configurations found in a typical network infrastructure. The 7505 is used as a low availability access router servicing a casual end user site supporting multiple LAN interfaces. A site of this nature is usually autonomous with processing done locally for the majority of the time.
      The 7507 series servicing the remotes performs the functions of the distribution and access layers. The 7507 features are useful in access locations where there are many different types of interface requirements, many LAN segments and supports high volume of data from the site to the WAN. As a WAN distribution router, the 7507 connects many of the remote access locations without going to the core routers. The 7513, as indicated earlier, is suitable for all the three layers of the router networking architecture. In Figure 2.14, the 7513 is illustrated as a core routing platform. In this example topology, the 7513 connects the core routers using an ATM backbone, the distribution routers with frame relay. Also note that the 7513 may feed other locations within its own building using FDDI and Ethernet.
    5. System Processors The Route Switch Processor (RSP) platform used on the 7500 series router is a combination of the router processor (RP) and switch processor (SP) originally used on the Cisco 7000 series router platform. Combining the functionality of the RP and SP into one board enables the RSP to switch and process packets faster and allows each platform to gain an extra slot for an interface processor. There are three types of RSP platforms. The base platform of each RSP type comes with 32MB of DRAM and 8MB of Flash SIMM memory. The 7500 series uses the Flash SIMM for storing and loading the Cisco IOS BOOT images necessary for the RSP to activate prior to executing any other functions. The DRAM is upgradeable from 32- to 64- to 128MB of DRAM with Flash memory upgrades using PCMCIA cards in up to two slots totaling 40MB. Each RSP comes with 128KB of Non-Volatile RAM (NVRAM) to store the IOS system running and startup configuration files.
      RSP1
      The RSP1 is the default RSP on the 7505 series router. It is only available on the 7505 router. The RSP1 stores the Cisco IOS image in Flash memory on the RSP or on up to two Intel Series 2+ Flash memory PCMCIA cards. The RSP1 has an external clock speed (bus speed) of 50MHz and internal clock speed (CPU speed) of 100 MHz.



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  9. #39
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    1. RSP2
    2. The RSP2 is the base RSP board supplied for the 7507 and 7513 series routers. The RSP2 operates at an external clock speed (bus speed) of to 50MHz and an internal clock speed (CPU speed) of 100 MHz. The RSP2 platform of the RSP system processors supports the High System Availability (HSA) features. Using two RSP2 system processors, the 7507 and 7513 provide for RSP failure recovery as the slave takes over for the master if the master should experience an outage. The default for identifying the system master is the RSP2 occupying slot2 on the 7507 and slot6 on the 7513 router. The order is configurable but it is highly recommended that the defaults be taken when using HSA. A caveat to using HSA is Cisco IOS Release 11.1(5) or higher and ROM monitor version 11.1(2) or higher. Each RSP2 must have the same version of ROM monitor installed for HSA to function properly.
    3. RSP4
    4. The RSP4 platform of the RSP system processors is available for the three 7500 series platforms. Its external clocking speed (bus speed) is 100 MHz and supports an internal clocking speed (CPU speed) of 200 MHz. The RSP4 uses DIMM chip sets for DRM memory. As such, the RSP4 DRAM configuration is 32-, 64-, 128- or 256MB. AN enhancement to the RSP4 over the RSP1 and RSP2 is the use of static RAM (SRAM) for packet buffering and a secondary cache memory for CPU functions. The RSP4 supports any type of PCMCIA flash memory card for flash memory. PCMCIA card formats come in three types. PCMCIA Type 1 and 2 and usable in slot 0 and slot 1. Type 3 PCMCIA flash memory cards are only supported in slot 1 of the PCMCIA slots for the RSP4. Like the RSP2, the nRSP4 supports HAS. Support for HAS on the RSP4 is dependent to the level of Cisco IOS and ROM monitor. HAS is fully supported on the RSP4 using Cisco IOS release 11.1(8)CA1 and ROM monitor version 11.1(8)CA1 and higher.
    5. Memory
    Memory on the RSP and any interface processor is paramount to efficiently running the routers. The more the better. It does not hurt to order the highest amount of memory available for any platform as an inexpensive insurance policy against poor design or "memory leaks" from the IOS or microcode software. That aside, the 7500 series platform comes with DRAM memory size recommendations based on the number of IP routes in a network. Cisco categorizes network sizes into the following:
      • Small networks – less than 2,000 IP routes
      • Medium networks – between 2,000 and 10,000 IP routes
      • Large networks – greater than 10,000 IP routes
    The for the RSP1, RSP2 and RSP4 system processors on each on the 7505, 7507 and 7513 router platform the DRAM memory requirements are recommended to be:
      • Small networks – 32MB
      • Medium networks – 32MB
      • Large networks – 64MB
    Cisco highly recommends that even if some networks are much smaller than the 2,000 IP routes a minimum of 32MB of DRAM is beneficial for router performance.
    The Flash memory PCMCIA cards available for insertion into slot 0 and slot 1 of the RSP boards are available in different memory sizes. The default card comes with 8MB of memory and has a default IOS software image stored. If a spare is ordered or purchased it must first be formatted before use. PCMCIA cards used on RP boards from a 7000 series router must be reformatted for use on the 7500 series router due to a difference in formatting of memory on the different system processors.
      1. 7200 Series The Cisco 7200 series router is a change in the routing platform architecture for Cisco. The architecture of the interface slots is based on the technology conceived with the Versatile Interface Processor 2 (VIP2) boards from the 7x00 series. Instead of using slots the 7200 series uses port adapters. Figure 2.15 illustrates the adapter layout for the 7200 series router.
        The 7200 series platform is available in two formats. The 7204 supports up to four port adapters while the 7206 supports up to six port adapters. Each platform requires a network processing engine (NPE) and an Input/Output (I/O) Controller processor. The I/O Controller has two slots for PCMCIA flash memory cards and can be optionally configured with a Fast Ethernet interface using an MII connector. Each port adapter supports the OIR function allowing non-interruption of port upgrades or replacements. As found in the 7x00 series the replacement of like-adapters are automatically configured up on insertion.



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  10. #40
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    1. The 7200 series uses a peripheral component interconnect (PCI) bus architecture in support of the various network interfaces available using the port adapters. This bus architecture is built on two primary PCI buses and a secondary PCI bus providing a high-speed mid-plane rate of 600Mbps. A second power supply is available for added redundancy enhancing high availability.
    2. Usage The 7200 is positioned as a low volume core router or medium distribution router. Network Layer 3 switching support directly supported by the 7200 series makes it an excellent candidate as a distribution router for a large office complex or as a access router for many LAN segments with in the office complex as Figure 2.16 illustrates.
    3. Network Processing Engine Maintenance and execution of system management functions are supported by the network processing engine (NPE) on the 7200 series platform. The NPE works with the I/O Controller to monitor environmentals and share in system memory management. There are two versions of the NPE. The NPE-100 maintains an internal clock speed of 100MHz and an external clock speed of 50Mhz. The higher performance NPE-150 uses an internal clock speed of 150MHz and an external clock speed of 75Mhz. In addition the NPE-150 includes 1MB of packet SRAM for storing packets used in fast switching. The NPE requires Cisco IOS software verison 11.1(5) or later for the 7206 and 11.1(6) or later for the 7204.
    4. Memory
    5. Memory requirements on the 7200 series are dependent on the varied adapter configurations possible with each platform. Appendix C details the memory configuration requirements for the 7200 series platforms. The NPE come standard with 32MB of DRAM. This memory is incremental in 8-, 16- or 32MB SIMMs totaling 128MB. Both the NPE-100 and NPE-150 have a unified cache memory of 512KB as a secondary cache for the Orion R4700 RISC processor.
    6. The I/O Controller for the 7200 series provides NVRAM for the storage of system configurations and logging environmental monitor results. The two PCMCIA slots found on the I/O Controller support the Intel Series 2+ Flash Memory PCMCIA formats. These PCMCIA cards have 8-, 16- or 20MB of flash memory on board. The total available for the two slots combined is 40MB.
    7. 7000 Series
    8. The Cisco 7000 series was the original "big" router platform introduced. It was the replacement for the Cisco AGS and AGS+ router platforms. The 7000 platform itself has since been replaced by the 7500 platforms. The Cisco 7000 comes in two platforms as Figure 2.17 depicts. These are the 7000 and the 7010 series. The 7000 has a total of seven slots. Five of these slots are used for interface processors and two for system processors. The 7010 series is smaller and offers a total of five slots. Three of the slots on the 7010 are used of interface processors and the remaining two slots provide support for system processors.
    9. OIR was originally introduced with this platform along with a backplane called the Cisco extended bus (CxBus). The CxBus architecture provided a data bus throughput of 533Mbps on the 7000 series. The 7000 series supports up to two power supplies to enhance availability. However, the series itself does not support the high system availability feature found on the 7500 series platforms.
    10. Usage The 7000 platforms were initially developed primarily as a core router. However, the need for higher port densities and faster processing have moved the 7000 series out of the core and into the role of a small to medium distribution. As shown in Figure 2.18, the 7000 or 7010 is used as a distribution router servicing a minimal amount of access locations.
    11. System Processors
    On introduction of the 7000 platform Cisco used a Motorola 68040 CPU clocked at 25Mhz.. While this was considered fast for the time it has since been antiquated. The CPU is found on the Router Processor (RP) board. The RP is installed in slot 6 of the 7000 series and slot 4 of the 7010 series. In concert with the RP, the 7000 platform utilized three models of a Switch Processor (SP). These are the Switch Processor (SP) Silicon Switch Processor (SSP) and Silicon Switch Processor–2MB (SSP-2MB). The SP offloaded the responsibility of managing the CxBus from the CPU on the RP board. Thus, allowing the RP to efficiently manage system functions. Further enhancements using a Silicon Switch Engine (SSE) on the SP allowed the SP to examine incoming packet data link and network link header information making an intelligent decision on whether the packet should be bridged or routed and forward the packet to the corresponding interface. The speed of the decision process was enabled by using a silicon-switching cache which kept track of packet information through the router. The SSE is encoded in the SP hardware and in this configuration is called a Silicon Switch Processor (SSP). The SSP performs switching decisions independently of the RP thereby increasing the throughput and efficiency of system resources. The base SSP includes an extra 512KB of memory for handling switching decisions while the SSP-2MB provides an extra 2MB of memory. On the 7000 series the SP, SSP or SSP-2MB is installed in slot 5 and on the 7010 series the SP, SSP or SSP-2MB is installed in slot 3. The configuration for this installation is shown in Figure 2.19.
    Extending the life of the 7000 platform was made possible by the introduction of the Route Switch Processor 7000 (RSP7000) and the 7000 Chassis Interface (7000CI) processors. These two boards together give the 7000 platform the enhancements and ability to use the IOS software made for the 7500 router platform. The IOS software must be at IOS version 10.3(9), 11.0(6) 11.1(1) or later to support the RSP7000 processor and the 7000CI processor. The RSP7000 increases the performance of the 7000 platform by using a MIPS Reduced Instruction Set Code (RISC) CPU at 100MHz and a bus speed clocking (external clock) of 50Mhz. Use of the RSP7000 on the 7000 and 7010 series routers enables these platforms to use the Versatile Interface Processor (VIP) technology supported under the 7500 IOS software platform. The 7000CI monitors chassis specific functions relieving the RSP7000 from the following duties:
      • Report backplane and arbiter type
      • Monitor power supply status
      • Monitor fan/blower status
      • Monitor temperature sensors on the RSP7000
      • Provide router power up/down control
      • Provide power supply power-down control



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