The ICE Static Reflector 'reflects' audio traffic from unicast channels (those configured to use a Rallypoint) onto an IGMP multicast network. Static reflectors are primarily used to establish system interoperability, like bridging multicast traffic from a land mobile radio gateway or IP desk phone into an ICE push-to-talk channel.

Recall that ICE clients (such as mobile and desktop apps) can exchange multicast voice traffic with non-ICE entities, provided those entities support industry standard protocols such as RTP and ICE-supported CODECS like G.711, AMR, or Opus.

A common use case is when you have an entity such as a two-way radio gateway that "speaks" multicast and you and need ICE entities to talk to that system. This is easily accomplished by setting up a channel on ICE to use the codec the gateway is configured for, and to use the same multicast IP address and port configured on the gateway. Assuming the multicast flows cleanly between the gateway and the clients then everything works fine.

The following diagram illustrates a setup in which we have ICE Mobile and ICE Desktop clients on the same multicast network as the gateway. And the land mobile radio gateway is configured to forward a single talk group/channel/frequency on the radio system to bi-directional multicast that an ICE channel has been configured to use.

This setup works only if the ICE channel has been configured for multicast. In environments where multicast cannot be by all clients communicating on the channel (because, for example, some users on the channel are connecting from the open Internet), we need a system component to connect the multicast traffic produced by the radio system to the unicast/Rallypoint traffic produced by ICE. This component is the ICE Static Reflector.

As illustrated below, the ICE Static Reflector is placed on the same network as the radio gateway. The reflector connects to ICE Server (not illustrated) to receive information about what channels it should be reflecting and how to connect to whichever Rallypoint (or Rallypoints) are used by those channels.

Understand that multiple reflectors can be configured in your network, and that a given channel can be reflected on multiple reflectors at the same time. By doing so, multicast traffic can be picked up at one site, carried across a WAN link, and dropped onto the multicast network of a remote site. This is sometimes called a MUM trunk (multicast-unicast-multicast) and can be used to interconnect disparate radio systems with or without linking them to ICE users.