Juniper G10 CMTS, Hardware Manual

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G10 CMTS Components
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JUNOSg 3.0 G10 CMTS Hardware Guide 8
G10 CMTS Components
The G10 CMTS chassis employs front and rear modules that connect through a midplane.
Most of the cable connections are available in the rear of the unit. Following is a list of the
primary modules of the G10 CMTS:
!
NIC Module—Provides Ethernet switching functionality for upstream and downstream
traffic and for the Fast Ethernet interfaces. Houses two Gigabit Ethernet ports with
Gigabit Interface Converters (GBICs).
!
NIC Access Module—Fans out the Ethernet signals to individual 10/100Base-T lines,
which route to the HFC Connector Modules or Switched I/O Modules. A version of the
chassis provides internal Ethernet wiring between the NIC Modules and the DOCSIS
Modules.
!
DOCSIS Module—Performs all data path processing functions, including Layer 2 bridging
and Layer 3 forwarding. Processes IP data into DOCSIS packets. Converts and modulates
data for RF transmission. Reverses these processes for upstream data.
!
HFC Connector Module—Provides cable interfaces for a DOCSIS Module. Contains the
Fast Ethernet connectors for network-side data and the F-connectors for the HFC
cabling.
!
Switched I/O Module—Provides the same functions as an HFC Connector Module, but
provides four additional upstream F-connectors for the HFC cabling.
!
Chassis Control Module—Provides the management interface and runs the Routing
Engine software. Controls redundant protection functions and supplies software images
to all DOCSIS Modules. Runs the Simple Network Management Protocol (SNMP) agent
and environmental monitoring.
!
Hard Disk Module—Contains the system nonvolatile memory implemented as a hard
disk. This module is installed opposite the Chassis Control Module.
The G10 CMTS relays traffic between DOCSIS RF interfaces, on which the cable modems
reside, and the network-side interfaces (Fast Ethernet and Gigabit Ethernet). Figure 3 on
page 9 illustrates the relationship between the primary modules in the chassis.
Each DOCSIS Module can support up to four cable interfaces, where a cable interface (MAC
domain) contains at least one downstream interface and one upstream interface. Each NIC
Module supports two Gigabit Ethernet interfaces and four Fast Ethernet interfaces. The
Chassis Control Module provides an out-of-band Fast Ethernet management interface.
See the JUNOSg Software Configuration Guide: Interfaces, Cable, Policy, and Routing and Routing
Protocols for more information on interfaces.