Mocomtech CDM-570 - Manual (Page 280)

CDM-570/570L Satellite Modem with Optional IP Module Revision 4
IP Module Ethernet Interface Overview MN/CDM570L.IOM
15.3.10 easyConnect
™ Mode
easyConnect
™ is the Comtech EF Data IP modem intelligent networking solution that
allows a link to be setup with minimal configuration (no specific routes need to be
configured). The IP Module also supports non-IP traffic with easyConnect
™. All IP
traffic will be subject to user configured QoS restrictions.
15.3.11 easyConnect
™ Operation
The following is a detailed description of how an easyConnect
™ pair should be setup and
configured as well as information about how easyConnect
™ functions.
• Because easyConnect™ is a “smart wire,” the devices attached to it on either side of
the satellite should be on the same subnet and should not configure a next hop
address to be the CDM-570/570L IP address (as should be done with router mode).
For purposes of configuration, easyConnect
™ mode should be viewed to function in
much the same way as a bridge (however, without spanning tree protocol).
• All of the features that groom and optimize the satellite link in router mode are also
available in easyConnect
™ mode.
• easyConnect™ Multicast Option – Multicast packets in easyConnect™ mode are
identified using multicast MAC address. These identified multicast packets are either
routed or dropped based on the easyConnect
™ multicast option.
• easyConnect™ uses MAC (layer 2) addresses to learn where to send packets. In
comparison, router mode uses the destination IP address in the packet in conjunction
with the route table to determine where to forward the packets.
• The IP Module Ethernet interface in easyConnect™ mode is configured to be in
promiscuous mode with a data rate of 10/100BaseT Half Duplex/Full Duplex. The
IP Module needs to be in promiscuous mode in order to learn the attached
networking devices.
• Since easyConnect™ does not use a routing table, the determination of where to send
a packet is made by a learning process. When the system is powered-up, all packets
from each subnet (local and remote) will be sent over the satellite interface. However,
as each IP Module learns which devices are attached to their local Ethernet
interfaces, the IP Module begins to filter packets which it has learned are locally
attached to its Ethernet interface.
• The easyConnect™ learning/forwarding algorithm is as follows:
• If the packet is destined for the IP Module, then process it locally.
• If the packet is from the Ethernet interface, then send it to the Satellite interface;
OR if the destination layer 2 (MAC address) of the packets matches the source
layer 2 address for a packet we have already seen, then the destination MAC
address of this packet is on our local subnet; so why send it over the satellite
interface. In this case, the IP Module will drop the packet.
• If the packet is from the satellite interface, then send it out the Ethernet interface.
15–4