Juniper Networks G10 CMTS manual Switched I/O Module

Chassis Rear Modules

Switched I/O Module

The Switched I/O Module (SIM) contains a 6 U (267 mm) x 80 mm card with an 8 HP

(40 mm), double-wide rear panel. The module installs from the rear of the chassis and is hot-swappable.

The SIM has four RJ-45 Ethernet connectors, and four downstream F-connectors and eight upstream F-connectors for routing traffic to and from the HFC network (see Figure 20 on page 54).

!Fast Ethernet ports Eth0-Band Eth1-Bare not used.

! Upstream F-connectors US4 through US7 are not used.

!Ports DSR-INand DSR-OUTare not used.

The SIMs are located on the opposite side of the midplane from the DOCSIS Modules. These modules can occupy slots 1 through 4 and 10 through 13. There is one SIM for each DOCSIS Module.

The SIM provides the path and switching for Ethernet frames between DOCSIS Modules and the NIC Module.

!If you have a version 1 chassis, the Ethernet path is through a NIC Access Module cable connected between the NIC Access Module and the SIM.

!If you have a version 2 chassis, the Ethernet path is through the midplane. This eliminates the need for external NIC Access Module cables.

If a NIC Module is used in a version 2 chassis, you must use a SIM opposite each DOCSIS Module to provide the Ethernet connectivity between a DOCSIS Module and a NIC Module (through the midplane). You must not use an HFC Connector Module in this configuration.

The SIM receives downstream IP data from the NIC Access Module. IP data is then passed to the DOCSIS Module for processing into DOCSIS frames, then into an MPEG stream. The MPEG stream is modulated onto the RF carrier signal and routed back to the SIM (through the midplane) for downstream distribution through the F-connectors to the HFC network.

Upstream data follows the path in reverse order, starting with data coming into the upstream F-connectors. Figure 19 on page 52 shows this data flow. Also see “G10 CMTS Components” on page 8.Table 24 summarizes the definitions of the Fast Ethernet LEDs on the SIM.

Figure 20 on page 54 shows the SIM rear panel.

These LEDs can illuminate even when no cables are connected to the ports, as long as the link is present from the DOCSIS Module through the midplane.

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Hardware Component Overview 53