MRGLs are an ordered list of MRGs. The MRGs contain the media resources in the Cisco CallManager cluster. By assigning a MRGL to a device, you grant access to whatever resources are contained in the MRGs the MRGL contains.
B and C
The Media Resource Manager (MRM) manages all resources in the CallManager cluster. The software-based resources are all grouped under the Voice Media Streaming Application, which is activated in a Cisco CallManager server. Transcoding is one example of a hardware-based resource.
Hardware-based conference bridge resources are identified to the CallManager by their MAC address. Most of the configuration for these resources takes place on the resource itself.
The Voice Media Streaming Application is a service that runs on the Cisco CallManager servers. It allows the CallManager server to participate in all media resource functionality, including conferencing, media termination point, music on hold, and annunciator.
Network hold MoH is played anytime a person is placed on hold because of a network-related function. These functions include conference calls, transfers, and Call Park. User hold MoH sources are only played when the user literally presses the hold button on their IP Phone.
The Cisco CallManager server creates individual unicast streams for IP Phone users. Multicast support must be configured on a per-server and per-audio source basis.
When a MRGL is assigned at both the device pool and IP Phone level, the MRGL on the IP Phone takes precedence. The MGM will use the MTP resource listed first in the first MRG of the IP Phone MRGL.
By default, the media resources are assigned to the default MRG, which cannot be modified or deleted. The MRM will use a round-robin load-balancing system for these resources.
Because of the amount of processor resources consumed by session transcoding, this function is limited to hardware-based digital signal processor (DSP) resources.
The fixed audio source is always assigned audio source ID 51. This audio source ID must be linked to a fixed sound device in the CallManager server before it becomes active.
Part I: Cisco CallManager Fundamentals
Introduction to Cisco Unified Communications and Cisco Unified CallManager
Cisco Unified CallManager Clustering and Deployment Options
Cisco Unified CallManager Installation and Upgrades
Part II: IPT Devices and Users
Cisco IP Phones and Other User Devices
Configuring Cisco Unified CallManager to Support IP Phones
Cisco IP Telephony Users
Cisco Bulk Administration Tool
Part III: IPT Network Integration and Route Plan
Cisco Catalyst Switches
Configuring Cisco Gateways and Trunks
Cisco Unified CallManager Route Plan Basics
Cisco Unified CallManager Advanced Route Plans
Configuring Hunt Groups and Call Coverage
Implementing Telephony Call Restrictions and Control
Implementing Multiple-Site Deployments
Part IV: VoIP Features
Configuring User Features, Part 1
Configuring User Features, Part 2
Configuring Cisco Unified CallManager Attendant Console
Configuring Cisco IP Manager Assistant
Part V: IPT Security
Securing the Windows Operating System
Securing Cisco Unified CallManager Administration
Preventing Toll Fraud
Hardening the IP Phone
Understanding Cryptographic Fundamentals
Understanding the Public Key Infrastructure
Understanding Cisco IP Telephony Authentication and Encryption Fundamentals
Configuring Cisco IP Telephony Authentication and Encryption
Part VI: IP Video
Introducing IP Video Telephony
Configuring Cisco VT Advantage
Part VII: IPT Management
Introducing Database Tools and Cisco Unified CallManager Serviceability
Configuring Alarms and Traces
Using Additional Management and Monitoring Tools
Part VIII: Appendix
Appendix A. Answers to Review Questions