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Cisco AS5850 Universal Gateway Hardware Installation Guide
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Chapter 1 Cisco AS5850 Product Overview
Field-Replaceable Units
Only one common logic is active at a time, identified by the CLK LED on the RSC card front panel. The
active common logic is user-selectable and is independent from each RSC card. This assures that if you
need to replace an RSC, or if the slave RSC becomes the master, clocking remains stable. The selected
common logic should not be changed during normal operation unless a hardware failure is suspected or
diagnosed in the RSC card.
Gigabit Ethernet Egress
The RSC has dual gigabit Ethernet interfaces (See
Figure 1-9
.)
Table 1-8 on page 1-22
describes the
gigabit Ethernet interface LEDs, and
Table 1-9
details the pinout for the connector.
You can configure the two gigabit Ethernet ports with 1000BASE-SX or1000BASE-LX laser modules,
known as gigabit interface converters (GBICs.) GBICs are hot-swappable input/output devices that plug
into a Gigabit EtherChannel module, linking the module with the fiber-optic network (See
Figure 1-10
.)
The GBICs fit through cutouts in the front of the module and plug into connectors on the module. You
can install any combination of supported GBICs. Supported GBICs are listed in
Table 1-10 on page 1-23
.
Note
When using LX/LH GBICs with a 62.5-micron diameter MMF, you must install a mode-conditioning
patch cord (CAB-GELX-625 or equivalent) between the GBIC and the MMF cable on both the
transmit and receive ends of the link. The mode-conditioning patch cord is required to comply with
IEEE standards. The IEEE found that link distances could not be met with certain types of fiber-optic
cable cores. The solution is to launch light from the laser at a precise offset from the center by using
the mode-conditioning patch cord. At the output of the patch cord, the LX/LH GBIC is compliant
with the IEEE 802.3z standard for 1000BASE-LX.
Note
802.1q and 802.1p VLAN support is available on the Gigabit Ethernet interface of the ERSC. The
daughter card on the ERSC has two GigE ports and a front panel with FastEthernet ports.
