Communication channels which, if either one is sufficient, No need to use multiple channels in Communication, or for which there is a problem or not, can use it, switch to another channel.
Communication Channels If Methods for effective and adequate one. No need to use multiple channels of communication. Or for any channel are not available. Then switch to another channel.
Communication channels. If sufficient one effective way. There is no need to use the multiple channels.Communication channel or for any problems or not available. Then switch to the other channels.