The SIP URI follows the same form as an email address: user@domain. There are two
URI schemes:
1〉sip:[email protected] is a SIP URI. This is the most common form and was
introduced in [RFC2543].
2〉sips:[email protected] is a SIPS URI. This new scheme was introduced in
[RFC3261] and requires TLS over TCP as transport for security.
SIPS是使用TLS作爲安全傳輸協議，要求在傳輸SIP消息前先建立TLS連接