New Training: Cisco Collaboration: Voice Gateway DTMF and Codecs

In this 7-video skill, CBT Nuggets trainer Lalo Nunez reviews DTMF and codec selection in regard to Voice Gateways. Learn how to log SSH sessions and how to redirect the output to an FTP or TFTP server. Watch this new Cisco training.

Learn Cisco with one of these courses:

• Cisco CCNP Collaboration Core

• Cisco IOS XE Gateway and Media Resources

This training includes:

• 7 videos

• 49 minutes of training

You’ll learn these topics in this skill:

• Intro: Voice Gateway DTMF and Codecs

• DTMF Relay

• DTMF Relay Demo

• Codec Preference Lists

• Logging SSH session output

• Comparing two files (configs)

• Redirect session output

Which Codec Should You Use For DTMF Tones With Cisco Voice Gateways?

DTMF tones are the foundation of how telephony services work. DTMF tones are tones that are produced in varying, modulated frequencies that indicate which number is being pressed on a touch-tone phone. Traditionally, telephone network switches use these tones to route calls through telephony networks. IVR systems also use these touch tones to navigate through automated call prompts as well. Though today's VoIP-based networks may not depend on DTMF tones as much as a traditional touch-tone phone would, it's still important to ensure that DTMF tones can be passed through VoIP telephony systems.

For DTMF tones to work properly with Cisco equipment, the proper voice codec needs to be configured with voice gateways. Cisco recommends using lossless codecs for the best experience. Lossless codecs don't apply any compression to the voice media stream. Compression can distort DTMF tones and cause them not to function properly. Because of this, Cisco recommends using the G.711 codec, though other codecs will work as well.