Mon, 29 October 2007
Title: The Next Generation Cable Network: DOCSIS 3.0
Intro: The first DOCSIS standard, short for Data Over Cable Service Interface Specifications, standard was released by the company Cable Labs in 1997. In this podcast we take a look at the history of these standards and discuss DOCSIS 3.0 – the emerging standard in the cable industry.
Mike: Gordon, can you give us a brief history of the first DOCSIS standards?
Gordon – just covers up to 2.0
Mike: What are “tiered services??
Tiered services is business jargon for providing a service (such as telecom connectivity or cable channel service) according to separate, incrementally distinct quality and pay levels, or "tiers." We’re seeing this term used a lot recently in political debate regarding “net neutrality?.
Mike: Can you tell us a little more about DOCSIS 3.0?
Sure – in a nutshell it’s bigger, better, faster… It’s a needed response to products from competitors like Verizon with FIOs FTTH product and AT&T with the FTTN Lightspeed product. It’s triple play broadband – voice video and data.
- Much higher bandwidth through channel bonding
- Starts at 160 Mbps Downstream, 60 Mbps Upstream and goes up from there
- TI just rolled out their Puma 5 chip set a couple of weeks ago for cable modems. The chipset supports new DOCSIS 3.0 features, such as channel bonding, enable ultra high downstream bandwidth rates of at least 160 Mbps in the residential data and voice services configuration and 320 Mbps in video and business services configuration. In addition Puma 5 also supports greater quality of service with IPv6 and security with Advanced Encryption Standard (AES).
- Multiple 6 MHz (or 8 MHz) channels are bound, treating them logically as one
- IPv6 for advanced networking capabilities
- Expanded address space (2128 or 3.4 dodecillion)
Mike: How will IPv6 be rolled out?
There’s a lot of speculation now but it looks like it will be in to phases. John T. Chapman and Shalabh Goel from Cisco Systems have an interesting piece we’ve got linked in the shownotes (http://www.cable360.net/ct/sections/features/20942.html )
“The initial deployment phase allows the cable operator to set up an IPv6 control and management plane for managing the cable modems, set-top boxes, and multimedia terminal adapters (MTAs) with a cost-effective upgrade. In a subsequent deployment phase, cable operators can offer IPv6 directly to the home network. Many new devices are already IPv6 capable, and cable operators could soon be running the largest IPV6 networks in the world.?
Mike: What are some other key features of DOCSIS 3.0?
Other key related DOCSIS 3.0 features, which may be migrated over time, include:
• Enhanced security, including advanced encryption standard (AES), security provisioning and theft of service features;
• An upstream frequency range extension to 85 MHz and a downstream frequency extension to 1 GHz that allows an operator to add existing capacity with plant upgrades at a later date;
• Enhanced plant diagnostic features, including a cable modem diagnostic log, enhanced signal quality monitoring, extension of IP data record (IPDR) usage and capacity management.
Mike: How about the commercial services?
DOCSIS 3.0 specifications define two technologies for business services over DOCSIS: layer 2 virtual private networks (VPNs) and T-1 circuit emulation.
Business users will be able to videoconference from their PCs and PDAs and tap into corporate networks through VPNs; residential customers will subscribe to video-on-demand (VOD) and IP telephony services with low latency and minimum packet loss; and users everywhere will be able to upload and download files at much greater broadband speeds.
Mike: When will it be available?
According to FierceIPTV (http://www.fierceiptv.com/story/comcast-to-trial-docsis-3.0-iptv/2007-05-08 ):
“Comcast's planned converged-services trial will take place in a system that serves 50,000 homes, and will include an IP-video headend and DOCSIS 3.0 STBs, as well as the Slingbox from Sling Media, dual mode WiFi-cellular handsets and mobile phones capable of playing video.?
According to Chapman and Goel: The industry consensus is that fully compliant DOCSIS 3.0 CMTS* implementations will be available in 2008 to 2009. Many cable operators will require the most critical DOCSIS 3.0 features, such as downstream channel bonding and IPv6, far earlier. To meet this demand, many vendors’ CMTS products now include early implementations of such a subset of DOCSIS 3.0 features.
* CMTS: A cable modem termination system or CMTS is equipment typically found in a cable company's headend, or at cable company hubsite and is used to provide high speed data services, such as cable internet or Voice over IP, to cable subscribers.
In order to provide these high speed data services, a cable company will connect its headend to the Internet via very high capacity data links, also known as a circuit (canonical form of telecommunication circuit), to a network service provider. On the subscriber side of the headend, the CMTS enables the communication with subscribers' cable modems. Different CMTSs are capable of serving different cable modem population sizes - ranging from 4,000 cable modems to 150,000 or more. A given headend may have between half a dozen to a dozen or more CMTSs to service the cable modem population served by that headend.
One way to think of a CMTS is to imagine a router with Ethernet interfaces (connections) on one side and coax RF interfaces on the other side. The RF/coax interfaces carry RF signals to and from the subscriber's cable modem. (source: http://en.wikipedia.org/wiki/CMTS )