While SIP is a request-response protocol, there is not necessarily only one response to every one request.
虽然 SIP 是请求-响应协议，但每个请求不一定只有一个响应与之对应。
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Cerf has been working with NASA's Pasadena Jet Propulsion Laboratory—the people behind the recent Mars expedition—to design what he calls an "interplanetary Internet protocol."
The Kyoto Protocol, which set different duties for all countries to cut emissions, states that different countries should reduce their collective greenhouse emissions accordingly.