ANSI/SCTE 137-3 2017

Modular Headend Architecture Part 3: M-CMTS Operations Support System Interface

This specification defines the Network Management requirements to support a Modular Cable Modem Termination System (M-CMTS™) for headend components compliant to DOCSIS®. The purpose of this document is to define the management requirements for the M-CMTS architecture that enables an effective operation of the M-CMTS components.

The M-CMTS architecture separates the traditional CMTS into two parts. The first part is the downstream physical (PHY) component (known as a DOCSIS EQAM) and the second part consists of the IP networking and DOCSIS MAC functions of the CMTS (known as the M-CMTS Core). This separation of a CMTS into EQAM and M-CMTS Core introduces three new protocol interfaces to DOCSIS-compliant headend systems.

  • DOCSIS Timing Interface (DTI): Provides a frequency reference for M-CMTS Core and DOCSIS EQAM via direct connections to a DTI Server.
  • Downstream External PHY Interface (DEPI): Controls the delivery of DOCSIS frames from the M-CMTS Core to the EQAM devices.
  • Edge Resource Management Interface (ERMI): Provides EQAM devices registration and control to the Edge Resource Management device with the purpose of sharing EQAM resources with video systems such as Video on Demand (VoD).