Troubleshooting guide

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Cisco Broadband Local Integrated Services Solution Troubleshooting Guide
OL-5169-01
Chapter 1 Solution Overview
Solution Components
• IF-to-RF Upconverters—To be compatible with cable television system frequency division
multiplexing (FDM), install an external IF-to-RF upconverter that translates the IF signal to RF
carrier frequency. The upconverter also allows you to maintain your existing channel lineup.
Upconverters are available from many manufacturers and can be found in configurations ranging
from a fixed number of ports to flexible multislot, multiport models. Install and configure enough
upconverter ports to support the number of downstream cable modem card ports installed in each
CMTS you are installing. The number of units needed depends on the upconverter manufacturer.
The Cisco uBR7200 Series Universal Broadband Router Hardware Installation Guide lists
upconverter manufacturers, web sites for more information on upconverter products, and models of
upconverters that are compatible with the Cisco uBR7246VXR.
The upconverter is installed between the Cisco uBR7246VXR and the combiner. (See Figure 1-4.)
The combiner refers to all cables, amplifiers, and taps at the headend or cable distribution center that
connect the Cisco uBR7246VXR to the HFC network.
Depending on the channel plan you are employing, your upconverter(s) must support different
functionality. In the North American channel environment, your upconverter needs to receive a
44-MHz downstream IF transmission from cable modem cards in the Cisco uBR7246VXR CMTS
and transmit 6-MHz RF channel bands in the 54 to 860 MHz range. In an 8-MHz European channel
environment your upconverter needs to receive a 36.125 MHz downstream IF transmission from
cable modem cards in the Cisco uBR7246VXR CMTS and transmit 8-MHz RF channel bands in the
85 to 860 MHz range.
Refer to the documentation that ships with your upconverter for specific details on upconverter
operation and configuration.
Note An analog channel modulator with external IF loops is not suitable for use as a digital
Quadrature Amplitude Modulation (QAM) upconverter. These units typically do not have the
phase noise performance levels required for 64- and 256-QAM digital signals, and they might
cause degraded performance and possible system failure.
Core Switching Components
The core switching layer provides the IP core network (packet backbone). Included in this layer is the
Cisco Catalyst 6509 Ethernet LAN switch that provides connectivity between the Cisco BTS 10200
Softswitch and all of the solution components that it must communicate with.
Cisco Catalyst 6509 Ethernet Switch
Cisco Catalyst 6509 Ethernet switches, deployed in a redundant configuration to provide high reliability,
are used in the BLISS for Cable solution to provide Layer 2 connectivity among the IP core, Cisco BTS
10200 Softswitch, and ancillary servers and element management components necessary to provision
and maintain the BLISS for Cable solution, such as web cache, e-mail, and so on.
The Cisco Catalyst 6509 also provides Layer 3 functionality for routing signaling packets to edge and
trunking gateways, and to interconnect all servers within the SuperPOP. Each switch is configured with
redundant processors, switch fabric, internal clock, power supply and fans to provide high level
redundancy with redundant router moudules.
The Cisco Catalyst 6509 can also be used to aggregate the traffic from multiple CMTSs into a single
interface on a uBR. (The uBR component is optional depending on the network architecture.)