| An important part of troubleshooting is gathering alarms, issues, and node/network details related to the problems and issues you are investigating. Collecting such information often results in identifying and correcting the issue. By now, you already have a detailed list of items that correspond to the configuration and state of the node or network you are working on. This section provides you with a list of a few of the most commonly encountered issues and their corresponding potential causes. Poor or No Signal of an Electrical Circuit Cabling and wiring issues are common, particularly in new installations. The following are potential causes for this common issue: Incorrect DSx panel labeling (for example, wrong labels used in wrong ports). Miswiring at patch panel or to the Electrical Interface Assembly (EIA) at the rear of the ONS 15454. Damaged cable. Thin coax is commonly used because it is easier to work with. On long lengths of coax, 734 and 735A are spliced so that the thinner cable is at the connector head (allowing much higher densities) while allowing lengths of up 450 feet. During installation, cable-pulling tools are sometimes used. If the maximum torque is exceeded, the splice could be damaged, which would affect the cable. Cable connector that is not fully engaged. Defective cable from the test set providing the test signal. Misconfigured test set providing the signal (check settings such as framing and timing). EIA on the back of the ONS 15454 that was not fully inserted during installation. Ensure that it is fully inserted and that all screws are fastened. Possible bent pins during installation (where the back of the service card meets the chassis, or during installation of the EIA in the rear of the ONS 15454). Perform a visual inspection. Circuit that was provisioned to a different port, card, or node than originally intended. Out of Service (OOS) state on that circuit-terminating port. Electrical service card (DS1, DS3, or EC1) that is not fully inserted. Ensure that both top and bottom levers are fully engaged. Potentially bad card. Switch traffic to the protect card, and monitor the signal on the protect card.
Errors or No Signal of an Optical Link Warning All lasers in the 15454 are invisible; never look at the end of a fiber.
A significant amount of trouble on the ONS 15454 is traced back to a faulty fiber. The following list includes some of the most common causes related to optical link troubles: Incorrect fibers Improper fiber was used (for example, mistakenly using a multimode fiber instead of single-mode fiber). Incorrect fiber connections Fiber connectors were inserted in the wrong ports (for example, using Tx instead of Rx, and vice versa, or mistakenly mixing fibers for various ports). Air gap This significantly can reduce the power of the received signal. Always ensure that the connector end of the fiber is fully inserted. Scratched connectors When dealing with fibers, always ensure that connectors are properly capped. Dirty fibers connectors Fibers should always be clean before they are inserted into an optical port. Higher-speed interfaces are far more sensitive to dirty fiber connectors. Fiber could remain in that port for years to come. Kinked fibers Often fibers are pulled too hard, are stepped on, get caught in between the door and the cabinet's frame, or end up at the bottom of hundreds of pounds of other cablingjust to name a few. When a fiber is damaged (for example, a bend on a fiber has exceeded the maximum bending radius), it might appear to work fine for a while, but even if it is slightly moved, the signal on that fiber could severely degrade. Low light levels into an Rx port on a card Always ensure that the Rx fiber connector going into a port has a high enough level to meet specs. Too-high light levels Always ensure that the light coming into an Rx port does not exceed the maximum receive level specified for that card. Use of attenuators is required. Receivers on a card can be damaged if the light level exceeds its maximum receive levels.
Unable to Log into the ONS 15454 CTC is a great tool that greatly facilitates troubleshooting of the node or networkbut first you must be able to log in. The following are common causes that can prevent you from logging in the ONS 15454: Incorrect cable type is used For example, a technician in front of node who is attempting to log in directly from his PC to the TCC might be using a crossover cable instead of the required CAT5 straight cable. CAT5 RJ-45 connector tabs often break Using a CAT5 cable with a broken tab often causes a loose connection, resulting in a bouncing connection. CAT5 cables may have poor connection at the RJ-45 connector resulting in random or no connection When in doubt, use another cable. The browser, operating system, and JRE are not compatible Check the documentation for the relevant ONS 15454 software release, to ensure that you have a valid browser version and OS. As an example, Release 6.0 CTC supports the following operating systems: - Microsoft Windows NT - Microsoft Windows 98 - Microsoft Windows XP - Microsoft Windows 2000 - Solaris 8 - Solaris 9
Browsers and JRE supported by R6.0: - Netscape 7 (PC or Solaris 8 or 9 with Java plug-in 1.4.2) - Microsoft Internet Explorer 6.0 (PC platforms with Java plug-in 1.4.2) - Mozilla 1.7 (Solaris only) - - Wrong IP address Confirm that you have the correct IP address of the node you are trying to reach.
- - Mistyped IP address Confirm the address and retype it correctly.
- - Firewall configuration A firewall configuration can prevent your access if you are attempting to log in through a network. Check with your network administrator for access.
- - LAN connection wiring The LAN connection on the rear of the ONS 15454 might be wire-wrapped incorrectly.
- - Wrong PC/laptop IP configuration Look at the Procedure Guide for the various approaches available for connecting to the ONS 15454.
Follow these steps to troubleshoot basic connectivity: Step 1. | Open a DOS window on your PC (choose Start, Run; type cmd; and click OKif you are using a Windows 98 system, type command instead of cmd).
| Step 2. | Find your laptop's IP address (use the ipconfig command on the same DOS window).
| Step 3. | Ping your own IP address from that same DOS window using the ping command (for example, ping 192.168.1.101.make sure you type the address correctly). This confirms that your IP protocol stack is properly configured.
| Step 4. | Ensure that you have a working straight CAT5 cable connected between your laptop and the ONS 15454.
| Step 5. | Confirm that the network interface card (NIC) link light is either blinking or turned on. If not, ensure proper cabling and connections, and make sure that the NIC is fully inserted (if PCMCIA NIC is used in a laptop). The TCC2 and TCC2P cards also have link and activity LEDs at the RJ-45 jacks, which you can check to verify connectivity.
| Step 6. | In the already open DOS window, ping the ONS 15454's IP address from your PC to establish network connectivity (four replies from the ONS 15454 should be displayed). Congratulations! Receiving the four replies from the ONS 15454 confirms that you have a good cable and that your IP configuration works.
| Step 7. | Open a new browser window (Netscape or Internet Explorer).
| Step 8. | Type the ONS 15454's IP address in the URL address window and click the Enter key.
| Step 9. | Log in at the CTC login screen. At this point, enter a valid login and password. If the message "Loading Java Applet" does not appear on your browser, follow the procedure in the troubleshooting guide called "Browser Login Does Not Launch Java."
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Cannot Convert UPSR Ring to BLSR Ring Upgrading to a BLSR ring using CTC's BLSR Creation Wizard fails if an error resides on one or more of the 15454 spans. The Performance tab in the Card view identifies any errors in the section, line, or path on the optical ring cards. The span should be free of errors before you attempt to upgrade to a BLSR ring. Signal Degrade in Conditions Tab When troubleshooting, it is important to look at the conditions in the 15454. Telcordia defines signal degradation (SD) as a soft failure condition. SD and signal fail (SF) both monitor the incoming bit error rate (BER) and are similar, but SD is triggered at a lower bit error rate than SF. An SD is identified in the Conditions tab and in the alarm table if nonalarmed events are not being filtered. An SD commonly is caused by one of the following two items: A fiber problem - A physical fiber problem, such as a faulty fiber connection - A bend in the fiber that exceeds the permitted bend radius - A bad fiber splice
A degraded DWDM link
The SONET equipment commonly is seen as the problem, but in many situations, the dense wavelength-division multiplexing (DWDM) equipment or local fiber connections are at fault. A quick method of eliminating the SONET layer is to use a SONET test box to send a signal across the link. If errors still exist, the SONET equipment can be eliminated. At this point, you can investigate the DWDM equipment and look for faulty fiber connections. Ethernet Circuit Cannot Carry Traffic When traffic cannot be passed over an Ethernet circuit using G1Ks, first verify that the Gigabit interface converters (GBICs) are secure in the ports on the G1K card. The GBIC has two clips, one on each side of the GBIC, that secure the GBIC in the slot on the G1K-4 card. Also verify that the fibers are securely seated on the GBICs: A simple push on the fiber is always a good practice to ensure that you have a good fiber connection. If the problem is not at the physical layer, start to troubleshoot at the Ethernet layer. First, however, you must understand an important concept called link integrity, which helps eliminate many problems when turning up Gigabit or fractional Gigabit Ethernet (GigE) circuits using G-series cards on an ONS 15454 ring. End-to-end Ethernet link integrity essentially means that if any part of the end-to-end path fails, the entire path fails. In other words, a failure at any point of the path causes the G-Series card at each end to disable its transmit laser; this causes the devices at both ends to detect a link down. Also note that if one of the Ethernet ports is administratively disabled or set in loopback mode, the port is considered a failure point because the end-to-end Ethernet path is unavailable. In this example, both ends of the path are disabled because the port state is disabled or in loopback mode. Because of link integrity, you need to check all parts of the entire Ethernet path to ensure that an active end-to-end link exists. This checklist should uncover the problem that is preventing you from sending traffic over an Ethernet link: Verify physical connectivity between the ONS 15454s and the attached device. Verify that the ports are enabled on the Ethernet cards. Verify that you are using the proper Ethernet cable and that it is wired correctly, or replace the cable with a known-good Ethernet cable. Ensure that the proper cross-connects or circuit is in place between the two G1K cards. Ensure that you are using the appropriate GBIC (short reach vs. long reach) and that the GBIC used at the ONS 15454 Ethernet port matches the GBIC type used at the connecting equipment (at the other end of the fiber jumper). Find and clear any path alarms that apply to the port.
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