Installation guide

1-11
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 1 Overview
Operating Standards for Cisco IOS Software
Note The initial DOCSIS 1.0 specification required that the CM successfully obtain a response from
the ToD server before going online. Later versions of the specification made this optional—if
the CM cannot contact the ToD server after a certain number of attempts, it continues as is with
the provisioning cycle.
10. The CM also contacts the designated TFTP server to obtain its DOCSIS configuration file. If a valid
DOCSIS configuration file is received, the CM configures itself accordingly.
11. If specified in the DOCSIS configuration file, the CM enables BPI encryption and negotiates with
the CMTS for the proper key values.
12. The CM also performs any other steps specified by the DOCSIS configuration file, such as
downloading a new software image or downloading a secondary configuration file (for example,
downloading a Cisco IOS configuration file).
13. The CM then goes online and enters the maintenance state, passing traffic to and from its connected
CPE devices.
EuroDOCSIS Cable Plants
The EuroDOCSIS standard builds on the DOCSIS protocol, adding support at the physical layer for PAL
and SECAM channel plans. PAL uses a 625-line scan picture delivered at 25 frames per second where
the color carrier phase definition changes in alternate scan lines. SECAM uses an 819 line scan picture
that provides better resolution than PAL's 625-line and NTSC's 525-line resolutions.
The configuration and setup of EuroDOCSIS-based cable plants is similar to those of DOCSIS plants,
except that they use the EuroDOCSIS J.112 (Annex A) standard, which uses a similar physical layer as
Digital Audio Video Council/Digital Video Broadcast (DAVIC/DVB) J.83 Annex A networks.
EuroDOCSIS operation permits full bandwidth utilization of the 8 MHz downstream channel in the
85-to-860 MHz range, allowing up to 50 Mbps throughput. EuroDOCSIS also offers an upstream
frequency selection of 5 to 65 MHz, instead of the 5 to 42 MHz range used in DOCSIS networks.
Caution The Cisco uBR7111E and Cisco uBR7114E routers support only Annex A operation and should not be
used in production cable plants that support a 6 MHz channel plan.
A typical EuroDOCSIS architecture has four subsystems:
• High-speed fiber backbone—Carries Internet data, voice, and video between regional processing
centers, headends, and hubs.
• Headend—Aggregates content at the national and regional level and sends it to the fiber backbone.
• Hub—Combines regional programming with local content and sends that combined content to the
cable network.
• Interactive STBs with integrated EuroDOCSIS CMs—Connects subscribers to the cable network.
Video sources are Motion Picture Experts Group (MPEG) encoded and then fed into an MPEG
multiplexer that packs the MPEG video streams into a single stream. This stream is uplinked to a satellite
and then downlinked to multiple headends, which then distribute the MPEG stream directly onto the
HFC plant.
The STB receives signals from the cable network and displays them on a television. An STB with
EuroDOCSIS CM functionality supports two-way interactivity. Inside the EuroDOCSIS STB are two
tuners: