ANSI SCTE 232-2019 pdf download.Key Performance Metrics: Energy Efficiency & Functional Density of CMTS, CCAP, and Time Server Equipment
1.1. Executive Summary
This document is the second of multiple parts in a series that provides the cable operator with a standard reference to determine how well a piece of rack or shelf equipment performs in terms of minimizing the power required to do its particular job. In addition, this standard provides the means to quantify the amount of useful work the equipment provides per physical space. This part of the series focuses on the CMTS, CCAP, and other related cable operator critical facility equipment.
1.2. Scope
Cable operator networks are large expansive networks that involve hundreds if not thousands of miles of coaxial or fiber cable powered by power supplies in the outside plant and connecting customers to critical infrastructure facilities such as hubs, headends, data centers, regional, and national distribution datacenters. In these facilities is a vast array of equipment responsible for the production and support of the cable operator’s products and services such as voice, video, data, home automation and security, and Wi-Fi. The importance of powering all of these devices in the critical facilities is ever increasing as the customer expectation is for 100% availability due to the critical nature of the services being provided to business and residential customers. This document defines how to use a standard methodology to measure the density of hardware to meet the needs of optimizing critical space, as well as measuring energy consumption for the various network element classes. This part of the series focuses on the CMTS, CCAP, and other related cable operator critical facility equipment.
6.1.1. Introduction
The following subsections briefly describe Cable Modem Termination System (CMTS), and Time Server equipment, all of which operate in a cable television headend or distribution hub. Note that CMTS products are considered to be “legacy” equipment and are not expected to be widely used in new deployments. Later generation Converged Cable Access Platform (CCAP) equipment (which also supports CMTS functionality) is covered in section 8. A CMTS is fully defined by the CableLabs DOCSIS set of specifications. In short, a CMTS forwards (at layer 2 or layer 3) data packets between a wide area network via its network-side interfaces and customer premise equipment via its DOCSIS RF interface ports. There are two types of CMTSs (Integrated CMTS and Modular CMTS) as described below.
6.1.2. Integrated
CMTS (I-CMTS) With an I-CMTS, the downstream (DS) RF interfaces, upstream (US) RF interfaces, network-side interfaces and associated control plane and data plane processing entities all reside on a single CMTS network element.
6.1.3. Modular
CMTS (M-CMTS) With an M-CMTS, the interfaces and associated control plane and data plane processing entities are distributed among multiple network elements. The first of these network elements, called an M-CMTS core, is comprised of the upstream RF interfaces and the network-side interfaces. All upstream and network-side control plane and data plane processing for those interfaces is also handled by the M-CMTS core. Downstream MAC-layer processing is also performed on the M-CMTS core. A separate network element, the edge-QAM, contains the M-CMTS downstream RF interface ports as well as network-side interfaces. The M-CMTS core transmits downstream data content and control to the edge-QAM across the converged interconnect network (CIN) via the DOCSIS-defined DEPI interface (which is a form of an IP tunnel). The edge-QAM then performs the downstream physical-layer processing necessary to modulate and transmit the data content of the downstream channel onto downstream RF port(s) toward the CM and CPE devices on the HFC network. A third component, the DOCSIS Timing Interface (DTI) server provides a common sense of timing and frequency to the other M-CMTS components via the DOCSIS Timing Interface (DTI). See Figure 1.ANSI SCTE 232-2019 pdf download
