The ITU-T G.711 standard deals with what aspect of video conferencing?

While G.711 involves encoding, the choice 'coding and compression' is too broad - it implies general video or multimedia compression, whereas G.711 is exclusively scoped to narrowband voice audio encoding.

File transfer during a video conference is handled by separate data channel standards such as T.140, not by G.711, which has no file transfer functionality.

Call control signaling in video conferencing is managed by protocols such as H.245 (within H.323) or SIP, not by G.711, which is limited to audio codec specification.

ITU-T G.711 specifies pulse code modulation (PCM) encoding of voice-frequency audio at 64 kbps, using either A-law or mu-law companding algorithms to digitize analog voice signals. This standard is the foundational voice codec used in VoIP and video conferencing systems to encode and decode the audio channel, which is what voice compression during video conferencing refers to.