• Signaling of negotiated Guaranteed Bit Rate end-to-end: informing the other party of what is the granted bearer bit
rate of a terminal radio link is of great use to avoid waste of network resources and bad media quality;
• Signaling of non-received media packets: this is exploited through the usage of Negative ACKnowledgements (NACK)
packets sent by the receiver via the extended RTP profile (RTP/AVPF) [23];
• Signaling of Picture Loss Indication (PLI) by the receiver using the RTP/AVPF;
• Signaling of Codec Control Messages (CCM): in particular, the Temporary Maximum Media Bit-rate Request (TMMBR)
and the Temporary Maximum Media Bit-rate Notification (TMMBN) [24] are used to adapt the sender video bit rate
upon changes in the available maximum network bit rate.
• Dynamic signaling for changing speech codec bit rate: this signaling allows handling difficult radio conditions. In case
of speech packet losses also the transmission of redundant speech frames is allowed.