Chapter 4 Troubleshooting Cisco Unified MeetingPlace H.323/SIP IP Gateway Software Release 5.2.1

Troubleshooting Caller Connectivity

Dead Air Heard When Using an H.323 Device

Possible Cause—Data packets transmitted across IP are at times inconsistently sized.

Corrective Action—Ensure that Cisco Unified CallManager, the IP-gateway server, and the

Cisco Unified MeetingPlace Audio Server system are all be set to handle the same size data packet.

Dead Air Heard When Using a Cisco IP Phone

Possible Cause—There may be a poor connection between the Cisco IP phone and the Cisco Unified MeetingPlace Audio Server system.

Corrective Action—Verify that all associated connections are secure.

Fast Busy Signal Heard When Using a Cisco IP Phone

Possible Cause—The route pattern to IP-gateway server may not be configured properly in

Cisco Unified CallManager.

.

Corrective Action—To resolve a fast busy-signal problem, verify that the configuration information that you entered in the “Assigning a Cisco Unified CallManager Route Pattern to Point to the

Cisco Unified MeetingPlace H.323/SIP IP Gateway Release Release 5.2.1 Server” section on page 2-4is correct.

To verify the configuration, perform the following steps:

Step 1 In the Cisco Unified CallManager Administration page, choose Route Plan > Route Pattern.

Step 2 Verify that the settings are correct and make changes if necessary.

Step 3 When finished, click Insert.

Possible Cause—All IP ports on the Cisco Unified MeetingPlace Audio Server system are in use.

Corrective Action—Confirm that Cisco Unified CallManager and the voice gateway have been configured to handle IP call overflow.

Unable to Make Dial-Pad Key Selections When Using an H.323 Device

Possible Cause—The audio compression setting of the H.323 device may be incorrect.

Corrective Action—Use CCITT u-Law, 8.000 kHz, 8 Bit Mono for a Cisco Unified MeetingPlace Audio Server system with T1; use CCITT A-Law, 8.000 kHz, 8 Bit Mono for a Cisco Unified MeetingPlace Audio Server system with E1.

Administrator Guide for Cisco Unified MeetingPlace H.323/SIP IP Gateway Software Release 5.2.1

 

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Cisco Systems H.323/SIP manual Dead Air Heard When Using an H.323 Device, Dead Air Heard When Using a Cisco IP Phone

H.323/SIP specifications

Cisco Systems has been a leading force in the development and implementation of voice and video communication technologies, prominently featuring H.323 and SIP (Session Initiation Protocol). These protocols have become cornerstones in the realm of IP-based communication, facilitating seamless interaction across disparate devices and networks.

H.323 is a set of protocols that provides multimedia communication over packet-switched networks, such as the Internet. It supports audio, video, and data communications across IP networks, utilizing a variety of components including terminals, gateways, and multipoint control units (MCUs). One key feature of H.323 is its ability to handle both point-to-point and multipoint video conferencing. This makes it particularly suitable for enterprise applications where group communication is essential.

On the other hand, SIP is a more recent and flexible signaling protocol used for initiating, maintaining, and terminating real-time sessions that include voice, video, and messaging applications. Renowned for its simplicity and interoperability, SIP can work with various communication mediums and provides extensive capabilities for managing multimedia sessions. One of the primary advantages of SIP is its scalability, allowing it to accommodate everything from small-scale personal communications to vast corporate systems.

Both H.323 and SIP support features such as call transfer, call hold, and caller ID. H.323, however, can be more complex due to its broader array of standards and components, which might require substantial configuration. SIP, conversely, is designed to be lightweight, easily integrated with existing systems and applications, making it more user-friendly for developers.

Cisco Systems enhances these protocols through their robust telecommunication infrastructure that facilitates performance optimization, security, and unparalleled user experience. With advanced technologies like Cisco Unified Communications Manager and Cisco Webex, organizations can leverage H.323 and SIP to create cohesive communication environments. Security features such as encryption and authentication ensure that sensitive conversations remain private and secure, while Quality of Service (QoS) protocols manage bandwidth effectively to maintain consistent call quality.

Ultimately, the combination of H.323's established framework and SIP's flexibility ensures that organizations using Cisco Systems can effectively manage their communication needs, fostering collaboration and connectivity in today's fast-paced digital landscape. These protocols continue to evolve, adapting to the ever-increasing demands placed on modern communication systems.