Since DNS queries and responses are fairly small (1 packet each), the TCP protocol is not usually used: it provide automatic retransmission, ordering and general reliability, but at a cost of sending extra packets through the network. Instead we use the very simple "User Datagram Protocol", which doesn't offer any of the fancy TCP features we don't need.
阅读(2867) | 评论(0) | 转发(0) |
