Adequate administrative permissions
Using the Secure Real Time Transport Protocol (SRTP) requires synchronizing the times of all systems that are involved in the SRTP communication – Media Server, telephones, VoIP gateways etc. You can use e. g. the Network Time Protocol (NTP) for this purpose. Furthermore, the time zones of the relevant systems must be correctly configured.
With its default settings the Streaming provider is operable for the Media server solution at Telephony Control Server.
- On the Operation & Maintenance navigation tab, click on the Configuration & Monitoring navigation menu item.
- In the navigation tree, click on System Status -> Applications.
- In the list entry of the Telephony Control Server application click on to open the action menu of Telephony Control Server. to open the action menu of Telephony Control Server.
- Select Media Server configuration action menu.
A list displays all Media servers available in the Lotus Sametime Unified Telephony system environment.
- In the list select the Media Server link that you want to configure.
The configuration dialog of the selected Media Server opens.
- In the configuration dialog switch to the Providers tab.
- In the provider list select the link Streaming (RTP).
The configuration dialog with the Streaming provider settings opens.
- Enter under Binding Address an IP address that is available on the computer system of the Media Server. If the host name of the associated computer system can be resolved into an IP address in the network, you can also enter the associated fully qualified host name instead of the IP address.
The Media Server uses this address to communicate with devices via RTP.
When the IP address is newly set up or modified, the following Packet Filter Rules (Firewall Rules) need to be implemented in Telephony Control Server via the CLI interface. Only in this way the full Media Server functionality is activated.
In case of an internal Media Server, RTP Voice must be activated.
In case of an external Media Server, MGCP signaling must be activated.
In case of a cluster installation, RTP Voice as well as MGCP signaling must be activated.
- Enter a port number under Start range of RTP ports.
This port number specifies the first port of the port range the Media Server uses for the RTP-based transmission of outgoing media streams.
Each RTP transmission requires 2 UDP ports: one for transmitting the actual media stream via the RTP protocol, and one for the RTCP protocol that monitors the connection quality. The RTP protocol uses an even-numbered port, and the RTCP protocol of the associated connection uses the next higher odd-numbered port. Therefore, you need to specify an even number as the starting point for the port range.
If a firewall exists between the Media Server and Telephony Control Server, you need to activate the port configured here in this firewall.
- Specify under Number of RTP ports how many ports the Media Server uses for the RTP-based transmission of outgoing media streams at the most.
Since two UDP ports are reserved for one media stream (one port for RTP and RTCP each), the same number of UDP ports set here is once again allocated for the RTCP communication – even if the Media Server does currently not use RTCP.
Example: Number of RTP ports = 75
In this example a total of 150 UDP ports is allocated. 75 for the RTP and 75 for the RTCP communication.
Note: You need to adjust the default value of this setting in a way that it corresponds to the actual performance values of the computer system that you use for the Media Server. The value configured for Number of RTP ports must never be greater than is recommended for the performance of the computer system used.
If a firewall exists between the Media Server and Telephony Control Server, you need to activate the configured ports in this firewall.
- Select under Quality of Service which quality of service (DHCP) the Media Server is to use for the RTP communication.
The standardized and experimental service qualities can be selected.
Which quality of service you have to configure depends on the configuration of the used network infrastructure. Consult the administrator of the used network infrastructure about the adequate setting.
Telephony Control Server transfers the to be used DSCP to the Media Server MGCP service by default. The setting performed in this field will not be used until this transfer fails.
- Select under Security protocol the protocol to be used for the RTP communication between Media Server and telephone devices.
Only MIKEY is used for the management of keys used to encrypt RTP connections.
Only SDES is used for the management of keys used to encrypt RTP connections.
MIKEY und SDES
Either MIKEY or SDES is used for the management of keys used to encrypt RTP connections. Which option is actually used negotiates the Media Server with each individual telephone device.
- Select Save to copy the modifications.
Restarting the Streaming provider.
When you reboot the Streaming provider, all RTP connections that exist at the time of the reboot are interrupted.
Parent topic: Configuration Concept of the Media Server
How to Restart a Provider