Troubleshooting
This appendix lists system messages. It also describes problems you might encounter using MetroPlanner and their possible solutions. This chapter contains the following sections:
System Messages
Traffic Mapping Troubleshooting
Amplifier and DCU Placement Troubleshooting
B.1 System Messages
Table B-1 displays a list of MetroPlanner system messages and severities.
Table B-1 Error Messages
|
|
|
|
General |
Error |
Resulting network design has channels with shortcoming in TX-RX (at least one channel with red alarm) |
Error |
Process interrupted by user |
Traffic Mapping |
Error |
Network not feasible. All solutions exceeds system capacity of 32 wavelengths |
Error |
Maximum wavelength re-usage reached for channels with wavelength [wavelength] |
Error |
Two protected services assigned to the same wavelength |
Error |
Overlapped services assigned to the same wavelength |
Error |
Can't route service with hitless: [service name] |
Error |
Can't find alternate route for service: [service name] due to multiple HUB nodes along the path |
Error |
Can't route service: [service name] through HUB node defined in site [Site Name] |
Common (MetroCore MetroAccess) |
Error |
Span between site [Site Name] and [Site Name] is too long for OSC channel. Network unfeasible |
Error |
Span between site [Site Name] and [Site Name] is too long for OSC channel. Try to remove PASS-THROUGH suggestion from site [Site Name] |
Error |
Span between site [Site Name] and [Site Name] is too long for OSC channel. Try to unfreeze site [Site Name] |
Error (In case power in is below) |
[West/East] channel power in [Site Name] is near or below the fail low threshold |
Error |
Unfeasible Network design. [Site Name] should require usage of in-line attenuator |
MetroCore |
Error |
[West/East] [PRE/BST] amplifier in [Site Name] is working with a gain over [Gain Limit] dB |
Error |
Excessive span between [Site Name] and [Site Name] |
Error |
Excessive span and too much channels between [Site Name] and [Site Name] |
Error |
Dispersion compensation over limit. Try to unfreeze site [Site Name] |
Error |
Dispersion compensation over limit. Try to unlock PRE in site [Site Name] |
Error |
[PRE/BST] amplifier in [Site Name] [West/East] side is set to work in output power control mode |
Error |
Dispersion compensation over limit. System needs custom design due to fibre before [Site Name] |
MetroAccess |
Error |
Network not feasible: Exceeded 120 km |
Error |
Network not feasible: Exceeded maximum amount of chromatic dispersion for at least one of the network connections |
Error |
Network not feasible: Available amplification is not sufficient for the power budget requirements |
Error |
Network not feasible: No valid solutions found, with at maximum 5 amplifiers per sub-network |
General |
Warning |
Resulting Network design has some channel with shortcoming in TX-RX (at least one channel with yellow alarm) |
Warning |
Resulting Network design has some channel with shortcoming in TX-RX (at least one channel with orange alarm) |
Warning |
BOM does not contain any SFP module for the 2R Any Rate Client Service Type. Without SFP plug in, the board cannot work and it will be responsibility of the user adding the SFP as spare part |
Warning |
In site [Site Name], multimode patch-cords between client port of transponder and Y-Cable module are not in BoM |
Common |
Warning (In case power in is near) |
[West/East] channel power in [Site Name] is near or below the fail low threshold |
MetroCore |
Warning |
In [Site Name], [Dir: CW/CCW] direction a fixed attenuator of [Att. Value] dB is needed |
Warning |
In [Site Name], [Dir: CW/CCW] direction, before PRE amplifier, a fixed attenuator of [Att. Value] dB is needed |
Warning |
VOA loops exhausted without stabilization... |
Warning |
PMD warning on service [Service Name] |
General |
Info |
The generated BOM does not include SONET/SDH units |
Traffic Mapping |
Info |
No specific anti-ASE node is required for this traffic matrix requirement. |
Info |
Additional OADM ports added in Node XX for Anti-ASE: some channels in Optical Bypass. |
B.2 Traffic Mapping Troubleshooting
Traffic mapping troubleshooting encompasses problems that directly relate to network traffic.
B.2.1 Unfeasible Network
Symptom : Network not feasible. All the solutions exceed system capacity of 32, 16, or 8 wavelengths.
Table B-2 describes the potential causes of the symptom and the solution.
Table B-2 Unfeasible Network—System Capacity Exceeded
|
|
|
Some span in the ring must carry more than 32 wavelengths to implement the traffic demands. |
Remove all the forced routing direction on unprotected channels. |
Some span in the ring must carry more than 16/8 wavelengths |
Try changing the Project Options > Analyzer algorithm and check for feasibility. |
Symptom : Network not feasible. Overlapped services assigned to the same wavelength.
Table B-3 describes the potential causes of the symptom and the solution.
Table B-3 Unfeasible Network—Overlapped Services
|
|
|
Some unprotected channels with assigned wavelengths and directions overlap along the ring. |
Remove pre-assigned directions and/or wavelengths on the specific channels. |
B.2.2 Automatic Full-OADM NE Site Definition
Symptom : MetroPlanner automatically generated full optical add/drop multiplexing (OADM) nodes, even though they were not explicitly requested by the user.
Table B-4 describes the potential causes of the symptom and the solution.
Table B-4 Automatic Full-OADM Node Site Definition
|
|
|
Full-OADM layout automatic definition can occur under the following circumstances: • Large capacity nodes (adding/dropping more than 12 wavelengths per side or more than 16 wavelengths in one side) are implemented using full-OADM node configuration for cost and layout efficiency. •Small capacity nodes requiring more than 4 OADM units in one side are implemented with full-OADM. |
Avoid forcing wavelengths for connections from/to the node and forcing directions on unprotected channels (keep the default, which optimizes the routing and coloring processes). For a small capacity node, try to force the full-OADM site as Passive OADM (that has 5 slots available for x sides). |
B.2.3 Unfeasible Unprotected Service Circuits
Symptom : Some circuit channels have negative optical signal-to-noise ratios (OSNRs) and/or power margins.
Table B-5 describes the potential cause of the symptom and the solution.
Table B-5 Unfeasible Unprotected Service Circuits
|
|
|
The connection exceeds the optical target span budget. |
Try to force the connection direction in order to route it on the other ring direction. |
B.3 Amplifier and DCU Placement Troubleshooting
The amplifier and DCU placement algorithm is iterative and its convergence can depend on the initial state the optimizer is run against.
B.3.1 Unfeasible Service Circuits
Symptom : The user forced one or more nodes as Passive OADM, and some connections are unfeasible.
Table B-6 describes the potential cause of the symptom and the solutions.
Table B-6 Unfeasible Service Circuits
|
|
|
You cannot make the passive OADM forced node passive (excessive loss) for performance reasons. MetroPlanner attempts to place an amplifier in the node, but cannot because the node was forced to be an passive OADM. |
•Undo the forced passive OADM and allow the optimization process in the node. Then run the analyzer again. •Force an amplifier (such as a booster) in the previous node (if not already present). Then run the analyzer again. Note You should force the amplifier in both the clockwise and counterclockwise directions. |
B.3.2 Exhausted VOA Loop
Symptom : MetroPlanner generates a warning stating that the system requires an inline bulk attenuator, but the exact value of the attenuator will not be given as an output.
Table B-7 describes the potential causes of the symptom and the possible solutions.
Table B-7 Exhausted VOA Loop
|
|
|
The maximum number of amplifier and dispersion compensation unit (DCU) placement algorithm iterations has been reached. |
There are two possible solutions: •If there are no channels with negative margins, disregard the warning and do nothing. •If at least one channel has negative margins, try one of the following actions: –Try to force the preamplifiers in the transmit (Tx) node of the failed channels and run the analyzer again. –Look at the system specification and determine whether the system is feasible. If so, find the path of the channel with the worst OSNR margin and force an amplifier in the first passive location starting from the Tx node and run the analyzer again. |
B.3.3 Network Requires Custom Design
Symptom : MetroPlanner warns you that the system requires a custom design.
Table B-8 describes the potential cause of the symptom and the solution.
Table B-8 Network Requires Custom Design
|
|
|
Network requires a custom design due to mixed fibers traversed by service <ServiceX> |
Contact your Cisco representative to receive a custom network design. |
B.3.4 Dispersion Check Warning
Symptom : MetroPlanner issues a dispersion check error.
Table B-9 describes the potential cause of the symptom and the solution.
Table B-9 Dispersion Check Warning
|
|
|
MetroPlanner generates a dispersion check error for the following possible reasons: •You forced a site to a specific type, preventing the placement of a preamplifier. The analyzer requires a preamplifier on this site. •The dispersion check failed in a site where a preamplifier is already present. |
Attempt to lock a preamplifier in the first previous free site in the path of the failed channel. |
Dispersion check failed in Install mode where the dispersion of the previous span was modified. |
Try unfreezing the first or the last preamplifier along the failing service. |
B.3.5 Using 32 Channel DMX-O with Bulk Attenuators Option Disabled
Symptom : MetroPlanner generates the following message: "MetroPlanner tried to use the 32Chs DMX but this unit is not suitable in this network; try allowing the use of bulk attenuators or select the 32Chs DMX-O".
Table B-10 describes the potential cause of the symptom and the solution.
Table B-10 Disabled Bulk Attenuators Option
|
|
|
The user has disabled the use of bulk attenuators. The channels experience large power tilt. |
•Enable the bulk attenuators at the 32 DMX output ports. •Try to lock amplifiers (boosters in line sites, for example) to reduce tilt. •Select 32 DMX-O. |
B.3.6 The 32 Channel DMX Not Suitable due to Excessive Channel Tilt
Symptom : MetroPlanner generates the following message: "Due to excessive channel tilt, the 32Chs DMX is not suitable in this network; try unlocking an amplifier or select the 32Chs DMX-O".
Table B-11 describes the potential cause of the symptom and the solution.
Table B-11 Excessive Channel Tilt
|
|
|
The channel tilt cannot be recovered with the use of bulk attenuators at the DMX output, due to large channel power variations as the number of installed channels is varied. |
•Try to lock amplifiers (boosters in line sites, for example) to reduce tilt. •Select 32 DMX-O. |
Feedback