An apparatus for use in a Multimedia Telephony Services over IMS, MTSI-based user equipment (108, 204) configurable for video region-of-interest signaling and operation as an MTSI sender (108, 204), the apparatus comprising: memory (416, 504); and processing circuitry (414, 418, 502) configured to: signal video region-of-interest information for a first region-of-interest of an MTSI receiver (106, 202) in Real Time Protocol, RTP packets, the RTP packets to include at least a zoom command to capture the first region-of-interest, the first region-of-interest being a requested region-of-interest of the MTSI receiver (106, 202); decode received RTP payload packets from the MTSI receiver (106, 202), the RTP payload packets comprising video corresponding to the first region-of-interest; receive signaling in Real-time Transport Control Protocol, RTCP feedback reports from the MTSI receiver (106, 202) requesting a second region-of-interest, the second region-of-interest provided during an Session Description Protocol, SDP capability negotiation, the second region-of-interest being a predefined region-of-interest of the MTSI sender (108, 204); and encode video corresponding to the second region-of-interest in RTP payload packets for transmission to the MTSI receiver (106, 202). memory (416, 504); and processing circuitry (414, 418, 502) configured to: signal video region-of-interest information for a first region-of-interest of an MTSI receiver (106, 202) in Real Time Protocol, RTP packets, the RTP packets to include at least a zoom command to capture the first region-of-interest, the first region-of-interest being a requested region-of-interest of the MTSI receiver (106, 202); decode received RTP payload packets from the MTSI receiver (106, 202), the RTP payload packets comprising video corresponding to the first region-of-interest; receive signaling in Real-time Transport Control Protocol, RTCP feedback reports from the MTSI receiver (106, 202) requesting a second region-of-interest, the second region-of-interest provided during an Session Description Protocol, SDP capability negotiation, the second region-of-interest being a predefined region-of-interest of the MTSI sender (108, 204); and encode video corresponding to the second region-of-interest in RTP payload packets for transmission to the MTSI receiver (106, 202). signal video region-of-interest information for a first region-of-interest of an MTSI receiver (106, 202) in Real Time Protocol, RTP packets, the RTP packets to include at least a zoom command to capture the first region-of-interest, the first region-of-interest being a requested region-of-interest of the MTSI receiver (106, 202); decode received RTP payload packets from the MTSI receiver (106, 202), the RTP payload packets comprising video corresponding to the first region-of-interest; receive signaling in Real-time Transport Control Protocol, RTCP feedback reports from the MTSI receiver (106, 202) requesting a second region-of-interest, the second region-of-interest provided during an Session Description Protocol, SDP capability negotiation, the second region-of-interest being a predefined region-of-interest of the MTSI sender (108, 204); and encode video corresponding to the second region-of-interest in RTP payload packets for transmission to the MTSI receiver (106, 202).