I see a lot of the following warning log due to using channel origination as part of our normal call flow

handleDialEvent: Ignored DialEvent for unknown source channel null with unique id null

This stems from this piece of code in ChannelManager.java

void handleDialEvent(DialEvent event) {
        final AsteriskChannelImpl sourceChannel = getChannelImplById(event.getUniqueId());
        final AsteriskChannelImpl destinationChannel = getChannelImplById(event.getDestUniqueId());

        if (sourceChannel == null) {
            logger.warn("handleDialEvent: Ignored DialEvent for unknown source channel " + event.getChannel()
                    + " with unique id " + event.getUniqueId());
            return;
        }

This is normal though because Dial Events aren't expected to have a source channel when created via an originate (we do a lot of origination via AMI).

My suggestion would be to axe this check/warning entirely and make all the sourceChannel stuff further down
this function require that sourceChannel not be null instead.