Webex Edge Audio – Configuration Series Part 1

If you’ve heard about Webex Edge Audio, then you know about the benefits it can bring to your organization.  If you haven’t heard of Webex Edge Audio, please take a moment to get up to speed here.

In this multi-part configuration series, I will be walking through the Webex Edge Audio configuration on the Cisco Unified Communications Manager (CUCM), Expressway-C, Expressway-E, and Webex Control Hub in detail.

Gather info from Webex Control Hub

To begin, we will need to log into the Webex Control hub and obtain a list of Webex Dial-In Numbers, as well as the Lua Script to be used on CUCM.

  1. Log into the Webex Control Hub
  2. Click Services > Sites > your webex site
  3. Select Configure Site
  4. Under Common Settings, select Edge Audio
    • Click “Generate Lua Script”
      • Select “Export” to save the file
      • Select “Copy” to copy the contents of the Lua Script to a text file
    • Click the blue highlighted “Click here” text under the Dial-in Settings
      • You can now see all of the Webex Dial-In numbers
      • Copy this list to a text file for later use
Edge audio dial in settings

Configure Cisco Unified Communications Manager

The first thing we will do is create the SIP Normalization Script by copying and pasting the contents of the Webex Lua Script. Afterwards we will create a new SIP Profile which includes Early Offer, a new SIP Trunk Security Profile, the SIP Trunk to the Expressway-C, and the Edge Audio Route Patterns.

SIP Normalization Script

  1. Log into the Cisco Unified CM Administration page on the CUCM Publisher
    1. Navigate to Device > Device Settings > SIP Normalization Script
      • Select “Add New”
    2. Name: Sitename_Webex_Edge_Audio
    3. Description: Webex Edge Audio SIP Normalization Script for (Sitename)
    4. Content: Paste the contents of the Webex Lua Script
    5. Script Execution Error Recovery Action: Message Rollback Only
    6. System Resource Error Recovery Action: Disable Script
    7. Memory Threshold: 50
    8. Lua Instruction Threshold: 1000
  2. We will apply this SIP Normalization Script to the Expressway-C SIP Trunk in a later step.
Edge audio CUCM settings

SIP Profile – Early Office for Voice and Video Calls

  1. Log into the Cisco Unified CM Administration page on the CUCM Publisher
    1. Navigate to Device > Device Settings > SIP Profile
    2. Copy the “Standard SIP Profile for Cisco VCS” profile
    3. Change the name to “EO- Standard SIP Profile for Cisco VCS”
    4. Set the Early Offer support for voice and video calls to “Best Effort (no MTP inserted)
    5. Click Save
  2. We will apply this SIP Profile to the Expressway-C SIP Trunk in a later step.
Edge audio CUCM settings

SIP Trunk Security Profile

  1. Log into the Cisco Unified CM Administration page on the CUCM Publisher
    1. Navigate to System > Security > SIP Trunk Security Profile > Add New
    2. Name: Sitename_Edge_Audio
    3. Device Security Mode: Encrypted or Non-Secure
    4. Incoming Port: Ensure this port value does not conflict with any other entries
      • An example port to use would be 5070
    5. Click Save
  2. We will apply this SIP Trunk Security Profile to the Expressway-C SIP Trunk in a later step.
Edge audio CUCM settings

Edge Audio Codec Configuration

Edge Audio supports the G.722 codec which uses less bandwidth than other codecs.  G.722 is also a wideband codec which provides noticeably better sounding audio than other codecs such as G.711 and G.729.

  1. Log into the Cisco Unified CM Administration page on the CUCM Publisher
    1. Navigate to System > Enterprise Parameters
      • Ensure that Advertise G.722 Codec: Enabled
    2. Click Save
    3. Navigate to System > Region Information > Region and select Add New
      • Name the Region appropriately
        • Click Save
      • Set the Audio Codec Preference List: Factory Default Lossy
      • Set the Maximum Audio Bitrate: 64kbps (G.722, G.711)
    4. Click Save
    5. Apply this region to the device pool which is used for Edge Audio.

Configure a new SIP Trunk Between CUCM and Expressway-C

We cannot use an existing SIP Trunk, so be sure to create a new one.  Configure the SIP Trunk as discussed below.

  1. Log into the Cisco Unified CM Administration page on the CUCM Publisher
    1. Navigate to Device > Trunk > Add New
      • Trunk Type: SIP Trunk
      • Device Name: expwy-edge-audio-sip-trk
      • Under Destination, type the FQDN and Port for the Expressway-C
        1. Use port 5060 for non-secure and 5061 for secure
    2. SIP Trunk Security Profile: Sitename_Edge_Audio (the profile we created previously)
    3. SIP Profile: EO- Standard SIP Profile for Cisco VCS (the profile we created previously)
    4. DTMF Signaling Method: RFC 2833
    5. SIP Normalization Script: Sitename_Webex_Edge_Audio (the script we created previously)

NOTE: Other required settings such as Device Pools, Media Resource Group Lists (MRGL), Locations, Calling Search Spaces (CSS), and Call Classification will be dependent on your environment. Please take a moment and assign these settings based on your business requirements. 

Please reach out to the Covene team if there are any questions!

Edge audio CUCM settings Edge audio CUCM settings

Create a Route Group, Route List, and Route Pattern

In this step, we will need the list of Webex Dial-In Numbers that were copied/pasted into the Notepad document.  If you do not have these, please reference the steps at the beginning of this guide in order to log into the Webex Control Hub and obtain them.

NOTE: Depending on your environment, you may not need to configure all of the dial-in numbers.  For example; if your organization only operates out of the United States of America, and does not use other country dial-in numbers, then we would only configure the Webex Dial-In Numbers that begin with +1 for the USA.

NOTE: If you are currently using a prefix or escape code to make outbound calls, we will need to strip this on the Route Pattern and send the call in a fully qualified E.164 format, with or without the leading plus sign.

  • On the CUCM Publisher:
    1. Navigate to Call Routing > Route/Hunt > Route Group
      1. Select Add New
      2. Name: webex-edge-audio-rg
      3. Available Devices: expwy-edge-audio-sip-trk
      4. Select Add to Route Group
      5. Click Save
    2. Navigate to Call Routing > Route/Hunt > Route List
      1. Select Add New
      2. Name: webex-edge-audio-rl
      3. Cisco Unified Communications Manager Group: (choose based on your environment)
      4. Route List Member Information > Add to Route Group
        1. Select the webex-edge-audio-rg
      5. Click Save
    3. Navigate to Call Routing > Route/Hunt > Route Pattern
      1. Select Add New
      2. Route Pattern: (the Webex dial-in numbers)
      3. Gateway/Route List: webex-edge-audio-rl
              Edge audio CUCM settings

              Conclusion

              The Cisco Unified Communication Manager (CUCM) configuration is now complete.  At this point, if you were to dial a Webex Dial-In number, the call would be routed to the Expressway-C via the Edge Audio SIP Trunk.

              In the upcoming Part 2 of the Edge Audio Configuration Series, we will walk through configuring the Expressway-C and Expressway-E, as well as Firewall Port and Certificate requirements.

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