private void CloseChannel(CloseDvcPdu pdu)
{
if (!channelDicbyId.ContainsKey(pdu.ChannelId))
{
throw new InvalidOperationException("The channel has not been created, channel id:" + pdu.ChannelId);
}
DynamicVirtualChannel channel = channelDicbyId[pdu.ChannelId];
channelDicbyId.Remove(channel.ChannelId);
channel.IsActive = false;
}