Juniper Networks G10 CMTS manual G10 Cmts Features and Functions, Functional Overview

G10 CMTS Features and Functions

G10 CMTS Features and Functions

The G10 CMTS provides true multiservice support, including the ability to simultaneously support DOCSIS IP services and VoIP services.

Functional Overview

The G10 CMTS is usually connected directly to a Gigabit-class core router that is part of a multiple system operator’s (MSO) metropolitan core network. It receives network-side packet streams originating from the Internet, Media Gateways or video servers, then processes them into DOCSIS-compatible digital signals (MPEG) that are modulated onto an RF carrier for transmission downstream over the HFC network to the subscribers’ cable modems.

Upstream signals consist of protocol data units (PDUs) in data bursts from the cable modems. The G10 CMTS uses advanced scheduling algorithms to optimize the timing of these transmissions. The packets are processed to recover the payload data, then routed, as IP packets, to the appropriate destinations through the network-side interface.

The G10 CMTS’s high capacity of up to 32 downstream and 128 upstream interfaces and other innovative features are provided by the Broadband Cable Processor ASIC (application-specific integrated circuit).

Broadband Cable Processor ASIC

The Broadband Cable Processor ASIC provides all-digital processing of the return path. This, plus advanced noise cancellation and equalization algorithms, enables modulation rates beyond QPSK and allows traditionally problematic frequency ranges of the upstream spectrum to be utilized. All-digital processing also accommodates full spectrum analysis by capturing statistics of the upstream band in real time.

The Broadband Cable Processor ASIC incorporates key DOCSIS MAC (media access control) functions such as concatenation, fragmentation, encryption, and decryption. Accelerating these functions in hardware provides a high-performance, scalable CMTS solution that can process thousands of simultaneous DOCSIS service flows.

Advanced timing and digital signal processing algorithms allow more efficient use of the

RF spectrum, resulting in increased channel capacity.

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System Overview 7