SIP和SIPS URI之间的区别？

Question

我正在读SIP RFC 3261。我不明白sip uri和sips uri之间的区别。有人能帮上忙吗。

Answer 1

来自rfc3261的第一个注释：

The format for a SIPS URI is the same, except that the scheme is
"sips" instead of sip.

第二个注意事项，我猜你的问题可以在第26.2.2节(SIPS方案)中找到，即:它表明所有的跳数都需要保护，最常见的是通过TLS链路。

When used as the Request-URI of a
request, the SIPS scheme signifies that each hop over which the
request is forwarded, until the request reaches the SIP entity
responsible for the domain portion of the Request-URI, must be
secured with TLS; once it reaches the domain in question it is
handled in accordance with local security and routing policy, quite
possibly using TLS for any last hop to a UAS.  When used by the
originator of a request (as would be the case if they employed a SIPS
URI as the address-of-record of the target), SIPS dictates that the
entire request path to the target domain be so secured.

当sips出现在To或From标头中时，其他规则也适用。例如，当sips出现在To标头中时，它表示使用安全链接的“愿望”。当在Request-URI中使用时，它是必须的。

在使用sips时，您可能还需要在Contact报头中使用sips。sips最终将在对话框中的其他请求的Request-URI中使用，因此您必须注意在Contact标头中使用正确的sip/sip。