Which codec is the default video compression format for most Cisco IP video endpoints?

A.
G.711

B.
G.729

C.
H.261

D.
H.263

E.
H.264

Explanation:
264 is the default video compression format for most Cisco IP video endpoints. Video formats, which are
commonly referred to as codecs, specify how video compression is to be handled. H.261 and H.263 are also
video codecs. However, neither H.261 nor H.263 supports HD video. By contrast, H.264 supports HD video.
G.711 and G.729 are not video codecs; they are audio codecs. G.711 provides higher-quality audio output but
requires more bandwidth. G.729 provides lower-quality audio output and requires much less bandwidth;
however, G.729 does not transmit fax signals, touch tones, or any other type of complex audio very well.

Cisco: Cisco Video and TelePresence Architecture Design Guide: Basic Video Concepts: Video Compression
Formats