Cisco Systems OL-21035-01 manual Troubleshooting and Maintenance General Troubleshooting Tips

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Chapter 6 Troubleshooting and Maintenance

General Troubleshooting Tips

Table 6-2

ATA 187 Troubleshooting (continued)

 

 

 

 

 

Summary

 

Explanation

 

 

 

 

Prolonged broadcast storms

A prolonged Layer 2 broadcast storm (lasting several minutes) on

 

cause phones to reset, or be

the voice VLAN may cause phones to reset, lose an active call, or

 

unable to make or answer a call

be unable to initiate or answer a call. Phones may not come up until

 

 

 

a broadcast storm ends.

 

 

 

 

Moving a network connection

If you are powering your phone through the network connection,

 

from the phone to a workstation

you must be careful if you decide to unplug the phone’s network

 

 

 

connection and plug the cable into a desktop computer.

 

 

 

 

 

 

 

 

 

 

Caution The computer’s network card cannot receive power

 

 

 

 

 

 

through the network connection; if power comes through

 

 

 

 

 

 

the connection, the network card can be destroyed. To

 

 

 

 

 

 

protect a network card, wait 10 seconds or longer after

 

 

 

 

 

 

unplugging the cable from the phone before plugging it

 

 

 

 

 

 

into a computer. This delay gives the switch enough time

 

 

 

 

 

 

to recognize that there is no longer a phone on the line

 

 

 

 

 

 

and to stop providing power to the cable.

 

 

 

 

 

 

 

 

Changing the phone

By default, the network configuration options are locked to prevent

 

configuration

 

users from making changes that could impact their network

 

 

 

connectivity. You must unlock the network configuration options

 

 

 

before you can configure them.

 

 

 

 

Dual-Tone Multi-Frequency

When you are on a call that requires keypad input, if you press the

 

(DTMF) delay

 

keys too quickly, some of them might not be recognized.

 

 

 

 

Codec mismatch between the

The RxType and the TxType statistics show the codec that is being

 

phone and another device

used for a conversation between this ATA 187 and the other device.

 

 

 

The values of these statistics should match. If they do not, verify

 

 

 

that the other device can handle the codec conversation or that a

 

 

 

transcoder is in place to handle the service.

 

 

 

 

Sound sample mismatch

The RxSize and the TxSize statistics show the size of the voice

 

between the phone and another

packets that are being used in a conversation between this ATA 187

 

device

 

and the other device. The values of these statistics should match.

 

 

 

 

Gaps in voice calls

Check the AvgJtr and the MaxJtr statistics. A large variance

 

 

 

between these statistics might indicate a problem with jitter on the

 

 

 

network or periodic high rates of network activity.

 

 

 

 

 

 

 

 

Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.0

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OL-21035-01

 

 

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Contents Troubleshooting and Maintenance Resolving Startup ProblemsChecking Network Connectivity Verifying DNS Settings Symptom ATA 187 Unable to Obtain IP Address ATA 187 Resets Unexpectedly Verifying Dhcp SettingsVerifying Physical Connection Identifying Intermittent Network OutagesEliminating DNS or Other Connectivity Errors Checking Static IP Address SettingsVerifying Voice Vlan Configuration Checking Power Connection Troubleshooting ATA 187 SecurityGeneral Troubleshooting Tips Troubleshooting and Maintenance General Troubleshooting Tips Where to Go for More Troubleshooting Information HalfduxcollisionexceedthresholdCleaning the ATA

OL-21035-01 specifications

Cisco Systems OL-21035-01 refers to a specific product or course pertaining to networking technologies offered by Cisco. While details of OL-21035-01 may allude to various learning modules, let’s explore its primary features, technologies, and characteristics that highlight the significance of Cisco’s offerings in the IT landscape.

At its core, OL-21035-01 encapsulates essential networking principles and is likely part of Cisco's extensive training portfolio focused on solidifying foundational knowledge in networking. One prominent feature includes a comprehensive curriculum that covers advanced routing and switching concepts. This ensures participants are well-equipped to manage and maintain modern network infrastructures, which are critical in today’s connectivity-driven world.

The learning materials may also leverage dynamic teaching methodologies, engaging participants through simulations and practical labs. This experiential learning approach allows individuals to demonstrate proficiency in configuring Cisco routers and switches, troubleshooting network problems, and implementing strategies for optimizing performance.

In terms of technologies, OL-21035-01 aligns closely with modern networking trends such as Software-Defined Networking (SDN), Internet of Things (IoT), and cloud computing. Understanding these technologies is essential as organizations increasingly rely on scalable, flexible, and intelligent network solutions. The program may also delve into Cisco's proprietary technologies like Cisco IOS, which is fundamental for managing network devices.

Another characteristic of OL-21035-01 is its alignment with industry standards and best practices. This ensures that professionals undergoing training are prepared for real-world scenarios they will face while managing enterprise-level networks. Cisco certifications, often obtainable through these courses, are recognized globally and can significantly enhance career prospects.

Additionally, OL-21035-01 stresses the importance of security in networking. Participants learn about robust security protocols, firewall configurations, and strategies to protect networks against cyber threats, ensuring that they remain resilient in the face of growing security challenges.

Lastly, Cisco’s emphasis on continuous learning is mirrored in the iterative nature of its offerings, encouraging IT professionals to stay updated with the latest advancements in technology. Consequently, OL-21035-01 not only serves as a stepping stone in one’s career but also fosters a culture of lifelong learning, vital for navigating the ever-evolving tech landscape.

In summary, OL-21035-01 embodies a holistic approach to networking education, focusing on critical skills development, contemporary technologies, and a robust understanding of security measures necessary for thriving in the IT sector.
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