Comtech EF Data CDM-760 - Manual (Page 116)

Front Panel Operation Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
6–30
Note the following:
CDM-760 Port Configuration Selection External Equipment Capability External Equipment Port Setting
Off Disabled Disabled
Auto 10 Base-T, 10/100/1000 Base-T Auto
1000BASE-T Full 1000 Base-T (GbE) Full Duplex**
100BASE-T Full 100 Base-T Full Duplex
100BASE-T Half 100 Base-T Half Duplex
10BASE-T Full 10 Base-T Full Duplex
10BASE-T Half 10 Base-T Half Duplex
** Forced 1000 Base-T Full Duplex is a non-standard mode of operation. Comtech EF
Data strongly recommends that you ALWAYS run 1000 Base-T (GbE) ports in Auto
Negotiate mode.
(CONFIG: INTF) (GBEIX)  Status
This read-only column displays the port’s current operating speed when you set the speed to
Auto. “NoLink” indicates that the modem detects no valid Ethernet device connection for the
port.
(CONFIG: INTF) (GBEIX)  FlowControl
The use of Flow Control or Pause Frames is useful when ALL devices connected to the modems
are set to honor Pause Frames. When used properly, Flow Control acts as a traffic valve in an
ACM environment.
Use the  arrow keys to set Flow Control as Enabled or Disabled. Press ENTER.
When Flow Control is Enabled, the modem begins to send Pause Frames once the WAN buffer is
approximately 87% full. Pause Frames are sent to ALL ports. Pause Frames will cease to be sent to
the Ethernet interfaces when the WAN Buffer Fill Status drops below 75% full.
If ANY device directly connected to the base unit Ethernet ports (GBEI1 / J5 | DATA, GBEI2 / J6 |
DATA or J7 | OPTICAL) does not honor Pause Frames, you should set Flow Control as Disabled,
as the interconnected device will not back off in an overflow condition and may cause all traffic
on the Tx and Rx links to become congested. All overflow traffic will be discarded.
Also note that, when the Remote InBand is set to Enabled (see Sect. 6.2.2.7.2 CONFIG: Remote
→Inband), any device connected to the base unit management port (J4 | MGMT) must also
honor Pause Frames to properly ensure system operation.
6.2.2.4.2.1 MAC Learning Operational States
(CONFIG: INTF) (GBEIX)  Learning
Use the  arrow keys to set MAC Learning as Disabled or Enabled. Press ENTER.