Which statement about the iSAC on Cisco Unified Border Element is true?
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.
The iSAC (internet Speech Audio Codec) is a codec used for voice and audio transmissions in IP networks. It is designed to deliver high-quality audio while conserving bandwidth. In the context of Cisco Unified Border Element (CUBE), iSAC is a codec that can be used for transcoding, interworking, and pass-through scenarios.
The correct answer to the question is C. iSAC has an adaptive frame of up to 60 milliseconds. This means that the codec can dynamically adjust the length of the frame used for encoding and decoding audio packets depending on the network conditions. In other words, when the network conditions are good, the codec can use a longer frame, which results in higher audio quality. On the other hand, when the network conditions are poor, the codec can use a shorter frame, which helps to minimize audio delay and packet loss.
Answer A is incorrect because iSAC is a wideband codec, not a narrow-band codec. This means that it can capture and transmit audio frequencies in the range of 50 Hz to 14 kHz, which is wider than the range supported by narrow-band codecs.
Answer B is incorrect because iSAC does not have a fixed frame size of 30 milliseconds. As mentioned earlier, the codec can adaptively adjust the frame size up to 60 milliseconds.
Answer D is incorrect because iSAC is designed to deliver high-quality audio in both high-bit-rate and low-bit-rate applications. The codec can operate at bit rates as low as 10 kbps, which makes it suitable for use in low-bandwidth networks.
Answer E and F are incorrect because iSAC is supported on the Cisco Unified Border Element (CUBE). The codec is commonly used in CUBE deployments for transcoding, interworking, and pass-through scenarios.