Webex Calling Media Optimization with Interactive Connectivity Establishment (ICE)
The Webex Calling Media Optimization feature makes it possible to have the best possible calling experience. By utilizing the Interactive Connectivity Establishment (ICE) protocol, the media channel between the supported devices can be improved. Through the use of media optimization, devices are able to communicate media directly to one another, which results in a reduction in both latency and bandwidth use.
Prerequisites and Limitations
Desk phones, Webex, and the Local Gateway solution all offer media optimization, although DECT and ATA devices are not included in this list of supported devices. When you make calls within your business, between devices that are supported, the media for your call will flow directly between the devices whenever it is possible to do so. This results in less latency and improved audio quality.
- Media optimization is enabled by default on all of the desk phone devices as well as Webex, and it typically does not call for any specific setting to be carried out.
- The command STUN usage lite, which is discussed in the section titled “Register Local Gateway to Webex Calling,” can be used to enable media optimization for the Local Gateway.
-
- STUN, which stands for “Session Traversal Utilities for NAT,” is a standardized method set that includes a network protocol for traversing network address translator gateways in real-time phone, video, messaging, and other interactive communications applications.
- ICE-lite is a protocol that is supported by the Local Gateway (CUBE). There are a few limitations to the ICE support that can be found on the CUBE, one of which is that ICE-lite is not supported with SIP-TDM gateways. For more information regarding ICE-lite support on CUBE, please see the following.
- In order to support media optimization on the Local Gateway, a minimum version of CUBE software of either 17.3 or 16.12.5 is required.
- In order to do media optimization using a Local Gateway, the device and the Local Gateway need to be reachable by the network. This can be accomplished in one of two ways:
- The Local Gateway will now have a public IP address assigned to it.
- A device that is part of the same network as the Local Gateway must be able to access the Local Gateway host address.
- Signaling information is uploaded to the Webex Calling cloud so that calls can be routed appropriately. When making calls with Webex Calling, you will always need to have an active internet connection. On the other hand, the majority of the traffic for a call comes from the media.
- Only within a single company can calls be optimized to their full potential. Because of legal constraints, interorganization calls must use the public switched telephone network (PSTN).
- If Call Recording is activated, the media associated with recorded calls will be uploaded to the cloud without being optimized.
Both ICE (Media optimization) and Call Recording are features that separately introduce a brief pause in the audio stream at the beginning of the call; however, when both of these capabilities are utilized together, the pause is significantly longer and more obvious to the call’s recipient.
Phases of Webex Calling Media Optimization
The Interactive Connectivity Establishment (ICE) protocol is utilized in media optimization in order to locate optimal media pathways.
This happens in the following phases:
-
Candidate discovery
Before making a call, an endpoint is required to locate a list of addresses at which it is able to receive media. These addresses, also known as candidates, include the local address of an endpoint as well as a server reflexive address that can be employed in order to make contact with the endpoint by means of a NAT. In order to ascertain the server’s reflexive address, a STUN server located within the Webex Calling cloud is queried.
-
Candidate exchange
During this phase, endpoints use SIP to communicate with one another and exchange the list of candidate addresses that was built during the Candidate discovery phase.
- Examinations of the connectivityEndpoints put the candidate addresses that have been traded between them through the Candidate exchange through their paces in order to find the most efficient media path between two devices.
- Optimization of the media pathThe endpoints now begin sending material across the optimized path by using a re-invite to communicate with one another.
Analytics for Media Optimization
Data for calls that have been optimized can be accessed through the Control Hub’s Troubleshooting tool or through the Media Quality analytics page. Both of these tools are located in the Control Hub.