Editing Cable modem termination system (section)

===Modular CMTS (M-CMTS)===
In a M-CMTS solution the architecture of an I-CMTS is broken up into two components. The first part is the Physical Downstream component (PHY) which is known as the Edge QAM (EQAM).  The second part is the IP networking and [[DOCSIS]] MAC Component which is referred to as the M-CMTS Core.  There are also several new protocols and components introduced with this type of architecture.  One is the DOCSIS Timing Interface, which provides a reference frequency between the EQAM and M-CMTS Core via a DTI Server.  The second is the Downstream External PHY Interface (DEPI).  The DEPI protocol controls the delivery of DOCSIS
frames from the M-CMTS Core to the EQAM devices <ref name="cablelabmcmts">{{cite web|title=Data-Over-Cable Service Interface Specifications Modular Headend Architecture|url=http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-M-OSSI-I08-081209.pdf|website=www.cablelabs.com|access-date=2015-02-27|archive-url=https://web.archive.org/web/20150227192938/http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-M-OSSI-I08-081209.pdf|archive-date=2015-02-27|url-status=dead}}</ref>  Some of the challenges that entail an M-CMTS platform are increased complexity in RF combining and an increase in the number of failure points.  One of the benefits of an M-CMTS architecture is that it is extremely scalable to larger numbers of downstream channels.<ref name="cmtsarchitecture">{{cite web|title=CMTS Architectures|url=http://volpefirm.com/docsis3_architecture/|website=volpefirm.com}}</ref>