Systems, apparatuses, and methods are described for monitoring data transmitted and/or received via multicast transmission and, based on latency, segment loss, and/or other occurrence, modifying sources and/or other characteristics of additional data transmission. The data may be video segments of media content items. Sources of video segments can be changed based on comparisons of rates of arrival of video segments, failure to receive segments, etc. Selection of an encoded version of content for multicast and/or unicast transmission may be based on indications of delay and/or non-receipt, and/or based on predictions of increased load on a network.