Nortel Networks 3500 User Manual

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Operation, administration, and maintenance (OAM) features   2-5
Planning and Ordering Guide—Part 1 of 2   NTRN10AN    Rel 12.1   Standard   Iss 1   Apr 2004
At the GE unidirectional add node, local client failures are propagated to the 
far end using Client Signal Fail (CSF) client management frames. Refer to 
 for list of ingress LAN alarms. If subrate GE WAN 
bandwidth is provisioned, enabling PAUSE flow control maybe required if the 
connected equipment can not properly send the GE traffic to match the 
provisioned WAN bandwidth.
Engineering rules
Unidirectional Gigabit Ethernet traffic is supported on Linear and UPSR 
rings.
Gigabit Ethernet Drop and Continue traffic is supported for UPSR rings 
only.
A valid Gigabit Ethernet signal must be connected to the receiver interface 
of the 2xGigE/FC-P2P at each drop node, otherwise GE idles will be 
transmitted.
Note:  An external optical splitter can be used to loop back the GE signal 
from the Tx port to the Rx port of 2xGigE/FC-P2P, if the connected 
equipment can not provide a valid GE signal.
A "Link down" alarm will be raised if you re-provision a bidirectional 
connection to unidirectional. To prevent this alarm from being raised the 
following steps must be performed:
— Delete all cross-connections to the WAN port
— Delete the Ethernet facility (DLT-ETH)
— Add the Ethernet facility (ENT-ETH)
— Re-enter the unidirectional cross-connection(s)
Note:  Refer to Bandwidth Management, 323-1059-320, Equipment and 
Facility Provisioning, 323-1059-350 and Alarm and Trouble Clearing, 
323-1059-543.
Auto-negotiation (AN) can be enabled, however both the receive (Rx) and 
transmit (Tx) fibers must connect to the same partner otherwise 
auto-negotiation will not complete properly.
It is recommended to disable auto-negotiation (AN) and Pause transmit 
(PAUSETX) frames at the drop nodes in this configuration. 
Alarm provisioning
Alarm provisioning allows you to disable or enable notification of an alarmed 
condition for any SONET alarm point on a network element. You can enable 
or disable alarm notification for one alarm or for a group of alarms with no 
effect on the alarm function. Disable an alarm to prevent that alarm from being 
reported to the user in any way (including alarm reports, TBOS, LEDs, or