Troubleshooting ATA 187 Security

Chapter 6 Troubleshooting and Maintenance

Checking Power Connection

In most cases, a phone will restart if it powers up by using external power but loses that connection and switches to PoE. Similarly, a phone may restart if it powers up by using PoE and then gets connected to an external power supply.

Table 6-1provides troubleshooting information for the security features on the ATA 187. For information relating to the solutions for any of these issues, and for additional troubleshooting information about security, see the Cisco Unified Communications Manager Security Guide.

Table 6-1 ATA 187 Security Troubleshooting

Problem

Possible Cause

CTL File Problems

Device authentication error.	CTL file does not have a
	Cisco Unified Communications Manager
	certificate or has an incorrect certificate.

Phone cannot authenticate CTL file.	The security token that signed the updated CTL
	file does not exist in the CTL file on the phone.

Phone cannot authenticate any of the configuration	The configuration file may not be signed by the
files other than ITL file.	corresponding certificate in the phone’s Trust List.

Phone does not register with	The CTL file does not contain the correct
Cisco Unified Communications Manager.	information for the
	Cisco Unified Communications Manager server.

Phone does not request signed configuration files.	The CTL file does not contain any TFTP entries
	with certificates.

General Troubleshooting Tips

Table 6-2provides general troubleshooting information for the ATA 187.

Table 6-2 ATA 187 Troubleshooting

Summary	Explanation

Daisy-chaining phones	Cisco does not support connecting a phone to another phone through
	the PC port. Each phone should directly connect to a switch port. If
	phones are connected together in a line (by using the PC port), the
	phones will not work.

Poor quality when calling mobile	In Cisco Unified Communications Manager, you can configure the
phones using the G.729 protocol	network to use the G.729 protocol (the default is G.711). When
	using G.729, calls between a phone and a mobile phone will have
	poor voice quality. Use G.729 only when absolutely necessary.

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

	OL-21035-01	6-7

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.

Checking Power Connection