ZyXEL Communications MSC1000G User Manual page 318

Chapter 10 IMA Screens
Table 148 IMA Group Setup (continued)
LABEL
Link
Min Link
Max Differential
Delay
Clock Mode
Group Symmetry
Frame Size
Frame Sync
Alpha
Beta
Gamma
Version
318
DESCRIPTION
This field displays the number of a single or multiple IMA links that are members of this
group. none displays if this group does not have any members yet. Click none or the IMA
link(s) to display the following screen where you can configure the link members.
Figure 209 IMA Group Setup > Link
1. Select the port(s) you want to add to this group.
2. Click Apply to update the settings in the previous screen. Alternatively, click Cancel to
exit this screen without making any changes.
Enter the minimum number of IMA links (1~8) the selected IMA group should support.
Once all of these IMA links become active, the IMA group automatically activates.
Disconnecting one of these IMA links deactivates this IMA group. The fewer IMA links you
configure here the less bandwidth the group can guarantee.
Enter the maximum number of milliseconds the IMA group can wait to receive delayed
data. If a delay exceeds this setting, the IMA triggers a Loss of Delay Synchronization
alarm and changes the state of the link to indicate a line defect.
Select the source of the clock which the IMA should use for the IMA link(s) in the selected
IMA group.
itc: Select this to have each IMA link use independent clock. That means, the time
between two IMA links might be different.
ctc local: Select this to have all IMA links in this group follow the IMA's clock.
ctc loop: Select this to have all IMA links in this group follow the remote connected ADM
device's clock.
This configures Symmetrical Configuration and Symmetrical/Asymmetrical Operation. The
available options are:
symop = Symmetrical Configuration + Symmetrical Operation
asymop = Symmetrical Configuration + Asymmetrical Operation
• Symmetrical Configuration: Each E1 physical line has an upstream and a downstream
IMA links. Select this to have an IMA link in this group be allowed to transmit and
receive data only when both the downstream and upstream links are active and
connected between the IMA devices.
• Symmetrical Operation: Both this IMA and the remote IMA device should wait for the
other end's "active confirmation" message before transmitting or receiving data.
• Asymmetrical Operation: Both this IMA and the remote IMA device can transmit or
receive data at any time.
Select the number of ATM cells the IMA converts into a frame. The possible options are 32,
64, 128, and 256. Leave it as the default if you do not need a specific setting.
These settings determine when the IMA has to change the state of an E1 link.
Enter the number of received consecutive invalid ICP cells that will cause the IMA line card
to change the link state to inactive.
Enter the number of received consecutive errored ICP cells that will cause the IMA line
card to change the link state to inactive.
Enter the number of received consecutive valid ICP cells that will cause the IMA line card
to change the link state to active.
Select the version of IMA protocol this IMA line card uses to communicate with the peer
IMA devices. Both peers must use the same IMA protocol version.
Management Switch Card User's Guide