Multicast is a communication with one sender and many recipients, so it's more efficient than sending the same call to every phone. This makes it a good solution for paging, where the same audio is going out to many devices.
If your organization needs to make announcements to larger groups of people in a facility, we recommend using a paging adapter with multicast capability. Digium Phones can be configured to be multicast receivers, so your announcements can be heard anywhere there is a phone.
You can do this using Switchvox to dial the paging adapter and make the announcement, or you can use the paging adapter separately and only use the Digium Phones as receivers.
In the Switchvox scenario, you use a paging adapter as an endpoint for a SIP Phone extension. That way, a Switchvox user can dial the extension of the paging adapter to make an announcement, and the paging adapter handles the multicast transmission to some or all of the Digium Phones on a network segment. For instructions on creating a SIP Phone extension, see
Create Phone or Virtual Extensions.
There a good selection of paging adapters with multicast support (e.g., CyberData, Valcom, Algo). From Switchvox's perspective, that device is just another SIP endpoint, so compatibility is straightforward.
Depending on the paging adapter you choose, you need to set up your network to manage the multicast transmissions. The paging adapter itself generally needs to be on the same network segment as the Digium Phones. The documentation for your chosen product should describe this.
To set up multicast address(es) to use on Digium Phones (requires Switchvox version 6.3 or later):
- Ensure that you are a Switchvox administrator with access to Tools > Multicast Addresses.
- Open that tool, and create an address that you want your Digium Phones to use.
- The Name field is for reference, so you can indicate the purpose of each address. The name indicated here is displayed on the Digium Phone as it receives a transmission.
- Switchvox suggests a standard multicast-reserved address, but you can use a multicast address that is appropriate on your network.
- If you create multiple addresses, be sure to put them in order of priority, most important at the top. Digium Phones only play one transmission at a time, whichever transmission has priority.
- Modify each SIP Phone extension that should receive the transmissions, using the Phone Settings tab Advanced Phone Options section. You can also put multicast addresses in the Extension Template or change them using Bulk Modify.
