Hitachi GR2000 Series, Installation Manual

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GR2000 Installation Guide
2-20 GR2K-GA-1002
Rev 6.03
2.3 Device Configuration
All of the GR2000 models have the same architecture and share common
components, including: Routing Manager (RM), Routing Processor (RP), Network
Interface Unit (NIF), power supply subsystem (PS), and cabinet. In addition, the
mid-range and high-end models (GR2000-6H, GR2000-10H, GR2000-20H)
implement a highspeed RM–RP connection by means of the Crossbar Switch (CSW).
The device components are collectively called the Basic Control Unit (BCU). A brief
description of each component is given below:
Routing Manager: The RM manages the entire router and processes routing
protocols. The routing processes include creation and update of routing tables
and forwarding routing tables to the Routing Processor (RP). In the GR2000-2S,
the Routing Manager/Processor (RMP) integrates the functions of the RM and RP.
In all other models, the RM is made up of two separate units: RM-CPU and
RM-IO.
Routing Processor (RP): The RP provides wire speed packet relaying in
accordance with the routing table information supplied by the RM. It also
performs ARP/ICMP processing, control of Network Interface Units, processing of
network interface protocols (e.g., PPP, frame relay, and ATM), statistic functions,
and error handling. In the GR2000-6H, GR2000-10H and GR2000-20H, an
additional RP provides load balancing and faster processing speeds.
Network Interface Unit (NIF): The NIF provides Layer 1 and Layer 2 support for
various interfaces. Since the NIF is separate from the RP and provides for specific
interfaces, a high degree of flexibility is achieved, meeting a wide range of user
needs.
Power Supply Unit (POW): The POW uses external power to generate a stable
direct current for the internal units of the router. In the GR2000-4S, GR2000-6H,
GR2000-10H and GR2000-20H, an additional POW provides a duplexed power
supply configuration that improves the systems availability.
Crossbar Switch (CSW): The CSW provides highspeed packet transfer between
the RM and RP for the following models of GR2000-6H, GR2000-10H,
GR2000-20H, GR2000-4, GR2000-10, and GR2000-20.
Basic Control Unit (BCU): In the GR2000-2S, the BCU consists of an RMP (a
duplexed BCU configuration is not available). In the GR2000-4S, the BCU
consists of the RM (a duplexed BCU configuration is not available). In the
GR2000-6H, GR2000-10H and GR2000-20H, the BCU consists of the RM and
the CSW; a duplexed BCU configuration option is available and is independent of
the duplexed power supply configuration. The BCU also contains the default
memory on the RM, flash memory cards, and software.
Ease of operation and maintenance is achieved by the hot-swapping capability of
components. On GR2000-2S, the NIF is hot-swappable when more than one NIF is
installed; on GR2000-4S and GR2000-4, the NIF and the POW are hot-swappable
when more than one NIF is installed, or when the power supply is duplexed. On the
rest of the models, the BCU, RP, NIF, and POW are hot-swappable when the BCU is
duplexed, more than one RP is installed, more than one NIF is installed, or the
power supply is duplexed.
Figure 2-26, Figure 2-27, and Figure 2-28 show the block diagrams of the GR2000
models. A brief explanation of each model follows.