CCIE Collaboration Exam: Types of Devices Supporting iSAC

Types of Devices Supporting iSAC

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Which two types of devices on Cisco Unified Communications Manager support iSAC? (Choose two.)



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A. B. C. D. E.


iSAC-Internet Speech Audio Codec (iSAC) is an adaptive wideband audio codec, specially designed to deliver wideband sound quality with low delay in both low and medium-bit rate applications.

Using an adaptive bit rate of between 10 and 32 kb/s, iSAC provides audio quality approaching that of G.722 while using less than half the bandwidth.

In deployments with significant packet loss, delay, or jitter, such as over a WAN, iSAC audio quality is superior to that of G.722 due to its robustness.

iSAC is supported for SIP and SCCP devices.

The Cisco Unified Communications Manager IP Voice Media Streaming App (IPVMSApp), which includes Media Termination Point, Conference Bridge, Music on Hold Server, and Annunciator does not support iSAC.

MGCP devices are not supported.

iSAC stands for Internet Speech Audio Codec, which is an adaptive codec used in Cisco Unified Communications Manager (CUCM) to provide high-quality audio communication over IP networks. iSAC dynamically adapts to network conditions by adjusting its codec bit rate in real-time. It also provides support for wideband and super-wideband audio codecs.

Regarding the question, iSAC is supported on two types of devices on CUCM. These are:

B. SIP - Session Initiation Protocol (SIP) is a signaling protocol used for establishing, maintaining, and terminating real-time sessions that involve voice, video, messaging, and other communications applications and services between two or more endpoints on IP networks. SIP devices such as SIP phones and SIP trunks on CUCM support iSAC.

C. SCCP - Skinny Client Control Protocol (SCCP) is a proprietary signaling protocol used by Cisco IP phones, voice gateways, and other devices to communicate with CUCM. SCCP devices such as Cisco IP phones also support iSAC.

The other options in the question are not correct:

A. MGCP - Media Gateway Control Protocol (MGCP) is a protocol used to control media gateways from external call control elements such as CUCM. MGCP does not support iSAC.

D. Music on Hold server - The Music on Hold (MoH) server is a software-based service that provides music or messages to callers when they are placed on hold. The MoH server does not support iSAC.

E. H.323 - H.323 is a protocol suite used for voice and video communication over IP networks. H.323 devices such as H.323 gateways do not support iSAC.

In summary, the correct answers to the question are B. SIP and C. SCCP.