Comtech EF Data CDM-760 - Manual (Page 118)

Front Panel Operation Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
6–32
Figure 6-2. MAC Learning Operations
As Figure 6-2 shows, it is important to note that enabling MAC Learning allows you
to reduce the amount of traffic over the satellite link when the modem is one
element on the LAN (Detail ‘A’). However, should a second Layer 2 path exist to the
far side equipment – this condition is known as “Spanning Tree” (Detail ‘B’) – this
will cause data flow failure. In a “Spanning Tree” state, the MAC Address of a
device – such as PC1 in the figure – appears to exist on both the WAN and LAN
sides of the modem. This corrupts the modem’s CAM table and causes its failure.
6.2.2.4.3 (CONFIG: INTF) (Optical)
If the CONFIG: Intf menu displays NONE, then the optional Optical Gigabit Ethernet
Interface SFP is either NOT plugged into the J7 | OPTICAL socket, or the Optical
Gigabit Ethernet Interface FAST Option is not activated. See Sect. 3.2.3.2 for further
information about this optional interface.
6.2.2.4.4 CONFIG:) INTF (PIIC1 / PIIC2)
You can access these menus only when the standard PIIC slots card is installed and
the modem senses the presence of an optional PIIC module.
6.2.2.4.4.1 (CONFIG:) INTF (PIICX=G703)
You can access these menus only when a PIIC G.703 E3/T3/STS-1 module is installed
in its PIIC slot.