The relay or proxying of media through an intermediary system is useful for some specific scenarios, such as NAT helping and network topology masking. Relaying media will increase the network requirements, bandwidth resources and CPU resources of your system.
In FlySIP SoftSwitch there are 3 places to get the RTP proxy configured:
1. Account level
Use Media Relay:
- Never
- When Necessary
- Always
2. Connection level
Use Media Relay:
- Never
- When Necessary
- Always
Preferred Media Relay:
- Built-in RTPproxy (internal)
- SMG (external, if cluster is used)
3. Routing group level
- Always
Preferred Media Relay:
- Built-in RTPproxy (internal)
- SMG (external, if cluster is used)
- From Connection (inherits the setting on Connection)
The usage cases:
1. Use Media Relay is set to Always on Account, then RTP would be proxied no matter what the settings are on Connection for Use Media Relay.
The Preferred Media Relay would be inherited from Routing group and Connection.
2. Use Media Relay is set to When Necessary on Account.
Case the call comes from NAT network, then RTP would be proxied no matter what the settings are on Connection for Use Media Relay.
The Preferred Media Relay would be inherited from Routing group and Connection.
3. Use Media Relay is set to When Necessary on Account.
Case the call comes from global (not NAT) network, then the settings on Connection for Use Media Relay would be checked.
Case it's set to Always, the RTP would be proxied, if it's set to Never/When Necessary - the RTP would not be proxied.
The Preferred Media Relay would be inherited from Routing group and Connection if the RTP is proxied.
4. Use Media Relay is set to When Necessary on Connection.
Case the call comes from NAT network, then RTP would be proxied no matter what the settings are on Account for Use Media Relay.
The Preferred Media Relay would be inherited from Routing group and Connection.
5. Use Media Relay is set to When Necessary on Connection. Case the call comes from global (not NAT) network, then the settings on Account for Use Media Relay would be checked.
Case it's set to Always, the RTP would be proxied, if it's set to Never/When Necessary - the RTP would not be proxied.
The Preferred Media Relay would be inherited from Routing group and Connection if the RTP is proxied.
6. Use Media Relay is set to Always on Connection, then RTP would be proxied no matter what the settings are on Account for Use Media Relay.
The Preferred Media Relay would be inherited from Routing group and Connection.
7. Any newly created connection/trunk has Use Media Relay set to When Necessary.