This best practice provides guidance on configuring RTCP RR/RS Bandwidth modifiers from EMA to support held calls for a Multimedia Telephony Service for IMS (MTSI) environment as described on the page AMR and RTCP Enhancements.
SBC ERE Configuration
Configuring Packet Service Profile in ERE
Execute the following command to configure PSP:
Enabling RTCP for HELD Calls
Execute the following command to configure the HELD calls:
Configuring RR and RS Bandwidth Values
Execute the following command to configure RR and RS bandwidth values:
Configuring IP Signaling Profile
Execute the following command to send the RR and RS bandwidth information in the SDP offer:
Configure Packet Service Profile on PSX
In the PSX Manager window, choose Packet Service Profile from the drop-down menu.
To create Packet Service Profile, right click on the Selection Area.
Select New from the resultant pop-up menu.
The Packet Service Profile window appears. Provide the Packet Service Profile name. Scroll down the display window to locate RTCP option.
Choose the RTCP option to enable it. This action enables the RTCP configurable flags.
The following parameters are displayed:
All available parameters require RTCP to be enabled.
Parameter Length/Range Default Description RTCP NA Disabled
When selected, this option enables Real-time Transport Control Protocol (RTCP) for the channel. RTCP is used to report traffic congestion data.
Packet Loss Threshold
(Packets Lost/100,000 Packets)
The packet loss threshold, measured in number of packets lost per 100,000 packets.
RR Bandwidth 100-4000 250 The RTCP bandwidth allocated to active data senders. RS Bandwidth 100-3000 250 The RTCP bandwidth allocated for receivers. Packet Loss Action NA None
The action to take when the packet loss threshold is exceeded on the channel. Possible actions are:
- None—No action.
- Trap—Generate an SNMP trap.
- Trap and Disconnect—Generate an SNMP trap and disconnect the call.
- Trap and Adapt—(applies to GSX only) Generate an SNMP trap and invoke an adaptation mechanism.
Enable RTCP Only For HELD Calls NA Disabled
If this parameter is enabled, SBC ignores the configured RR/RS values in the Packet Service Profile and send RR/RS = 0 in the offer/answer and disables RTCP when the call is active. When the call is HELD, and a RE-INVITE is sent, the CPN (SBC) uses the configured values in the Packet Service Profile for RTCP bandwidth and enables RTCP. When the call is RESUMED, the CPN (SBC) again disables RTCP by sending RR/RS=0 in the RE-INVITE.
If disabled the older behavior of SBC is applicable.
Termination For Pass-Through Calls NA NA When enabled, RTCP is terminated and generated locally even for pass-through calls.
Make the desired changes to these parameters.
Click Save to save the configuration.
Configure IP Signaling Profile on PSX
In the PSX Manager window, choose IP Signaling Profile from the drop-down menu.
To create IP Signaling Profile, right click on the Selection Area.
A pop-up menu appears. Select New from the pop-up menu.
The IP Signaling Profile window appears. Provide the IP Signaling Profile name.
Scroll down the display window to locate Common IP Attributes - Communicating With The Peer Regardless Of Call Direction section.
Enable the "Send RTCP Bandwidth Info" flag identified in the screen capture below:
The following flag is now enabled:
Parameter Length/Range Default Description Send RTCP Bandwidth Info NA NA When this flag is enabled, the RR and RS bandwidth information, b=RR: and b=RS:, is sent in the SDP offer.
- Click Save to save your changes.