Comtech EF Data CDM-570A - Manual (Page 472)

CDM-570L/570AL Satellite Modem with Optional Packet Processor MN-CDM570A
Appendix D Revision 2
D–14
• Managed Switch Mode also supports VLAN’s and when VLAN Mode is enabled, will forward
traffic as follows:
o If an untagged packet arrives at the Packet Processor, it will egress as a tagged packet
with the defined Native VLAN ID.
o VLAN entries can be added into the VLAN Table and to forward VLAN's over the satellite.
A VLAN entry is also needed on the receiving CDM-570A to receive the VLAN traffic and
they will egress as tagged VLAN's.
o If a tagged packet arrives at the Ethernet port, it will only be forwarded if there is a
matching VLAN entry in the VLAN Table and it will egress as tagged. If there is no
matching VLAN in the VLAN Table, the tagged packet will be dropped.
• VLAN operation in the CDM-570A/570AL-IP also includes full 802.1Q VLAN QoS support.
With the QoS Option enabled, the Packet Processor will read the 802.1Q VLAN Priority (7
through 0) that is in the VLAN Header in each VLAN frame received and will prioritize traffic
accordingly.
D.1.2.5.2 Combined Working Mode
In order greatly simply the configuration complexity, the working modes operation of modem
have been centralized in the single Working Mode configuration parameter, which in turn offer
the following functional parameters:
Mode Selection Function
Managed Switch
Managed switch with support for VLAN as well as advanced features
such as QoS, Header Compression and Payload Compression.
Primarily intended for operation in a point-to-point topology.
Router – Small Network Mode Hub side router in a Point-to-Multipoint network. Allows Sat-to-sat.
Router – Large Network Mode
Remote Router in a Point-to-Multipoint network. Packets from the WAN
are not allowed to be sent to the WAN. No longer requires HDLC
receive addresses to be configured.
Router – Point to Point Point-to-Point router in Point-to-Point configurations.
Router – Vipersat Hub router in a Vipersat Network.
The Vipersat “Unit Role” and “Expansion Role” parameters are not read-only.
D.1.2.6 Adaptive Coding and Modulation (ACM)
Appendix P. ADAPTIVE CODING and MODULATION (ACM) OPTION
Comtech EF Data’s VersaFEC® Adaptive Coding and Modulation (ACM) feature is a patents-
pending technology wholly owned and developed by Comtech EF Data and Comtech AHA
Enterprise Products Group. It can be used with the Packet Processor to maximize throughput.