User's Manual Part 2

Tech-X Flex
®
(NG2) Tech-X Flex User Guide - Firmware v06.50
7-33
Intro
Overview
Wi-Fi
Ethernet
System
IP/Video
MoCA
RF
Specs
MoCA operates using a hierarchical or “branching tree” physical topology with a “root” at the first coaxial
splitter, with additional devices (or nodes) connected to one or more secondary splitters as “branches”
distributed throughout the premises. The resulting logical network then appears as a mesh of point-to-
point connections established between each of the nodes. This differs from a switched Ethernet network
using twisted pair/Cat-5 copper, which typically uses a hub, switch, or similar device at a junction to
manage traffic flow. In a MoCA network, all nodes are logically interconnected on a single mesh,
including the router.
On a MoCA network, a single node acts as the network coordinator (NC), with all other devices acting as
member nodes. Using time-division multiplexing, the NC manages traffic flow by coordinating data
transmission from all network nodes, including itself. In order to transmit, a node must request a time
slot(s) from the NC which then periodically sends out a “schedule” of what node can transmit and when.
Any MoCA-compliant device can act as the NC and typically a network is configured to automatically
select the NC for optimal performance. Automatic NC selection also ensures that the network continues
to operate if the current NC fails or is removed from the network.
A single coaxial network can carry more than one MoCA network using different frequencies (or
channels) to differentiate the two. A common use of multiple channels is to allow a WAN and a LAN to
exist on the same physical cable. In the Figure 7-21 example, all nodes are interconnected by a single
coaxial tree, with a single cable connected to the router. Therefore, both the provider WAN (wide area
network) and the residential LAN (local area network) must operate on the same cables using different
channels. Each node must be configured to request admission to the proper network, with the router
configured to join both. Note that because the LAN and WAN are separate MoCA networks, they both
have their own NCs, which may be the same node (the router) or may be different nodes.
Despite the physical interconnectivity of this example network, the logical network concept operates
identically to other networks with respect to member nodes. In the Figure 7-21 example, the WAN
consists of the ONT and router only and the LAN consists of the router and all other devices except the
ONT. Even though every node has both the LAN and WAN signals at its coaxial port, only the router is
part of both networks. For example, the ONT will have the LAN signal available at its coaxial port, but it
will be configured to join the WAN only at its respective MoCA channel.
Figure 7-21 also shows an Ethernet-based connection to a computer, linked to the MoCA network by a
MoCA/Ethernet bridge. While set-top boxes (STBs) and other multimedia devices are typically MoCA-
ready and plug directly into the coaxial cable, home computers use twisted pair-based Ethernet or other
protocols for networking. Because an IPTV provider may supply broadband internet access as well, a
computer must interface with the MoCA network via the bridge (or perhaps a wireless connection) in
order to reach the provider WAN.
NOTE: As with any networking technology, there are a wide variety of configurations and devices
available which may differ from this diagram. Consult Other MoCA network examples/scenarios
on page 7-34 or a network engineer for more information about MoCA and the types of
networks you may encounter.
Preliminary issue - Limited distribution only!