直接路由定義與 RFC 標準Direct Routing - Definitions and RFC standards

本文說明 Microsoft 手機系統直通路由如何實現 RFC 標準通訊協定。This article describes how Microsoft Phone System Direct Routing implements RFC standard protocols. 本文適用于負責設定內部部署會話邊界控制器(SBC)與會話初始通訊協定(SIP) proxy 服務之間的連線的語音系統管理員。This article is intended for voice administrators who are responsible for configuring the connection between the on-premises Session Border Controller (SBC) and the Session Initiation Protocol (SIP) proxy service.

客戶 SBC 介面與 Microsoft 團隊後端的下列元件:The customer SBC interfaces with the following components in the Microsoft Teams backend:

  • 用於發信號的SIP proxyThe SIP proxy for signaling. 這是直接路由的網際網路式元件,可在 SBCs 與直接路由之間處理 SIP (TLS)連線。This is the Internet-facing component of Direct Routing that handles SIP (TLS) connections between the SBCs and Direct Routing.

  • 媒體的媒體處理器The media processors for media. 這是用來處理媒體流量之直接路由的網際網路式元件。This is the Internet-facing component of Direct Routing that handles media traffic. 此元件使用 SRTP 和 SRTCP 通訊協定。This component uses SRTP and SRTCP protocols.

如需直接路由的詳細資訊,請參閱手機系統 Direct 路由For more information about Direct Routing, see Phone System Direct Routing.

如需直接路由如何實現 SIP 通訊協定的詳細資訊,請參閱直接路由 SIP 通訊協定For more information about how Direct Routing implements the SIP protocol, see Direct Routing - SIP protocol.

RFC 標準RFC standards

直接路由符合 RFC 標準。Direct Routing complies with RFC standards. 連接至直接路由的 SBC 也必須符合下列 Rfc (或其後續任務)。The SBC connected to Direct Routing must also comply with the following RFCs (or their successors).

適用于支援非媒體旁路模式之裝置的標準Standards applicable to devices that support non-media bypass mode

下列標準適用于僅支援非媒體旁路模式的裝置:The following standards are applicable to devices that support only non-media bypass mode:

  • RFC 3261 SIP:會話初始通訊協定RFC 3261 SIP: Session Initiation Protocol
  • RFC 3325RFC 3325. 在受信任的網路中,針對斷言身分識別的會話初始通訊協定的專用延伸-有關處理 P 斷言身分識別標頭的章節。Private Extension to the Session Initiation Protocol for asserted identity within Trusted Networks--Sections about handling P-Asserted-Identity header. 直接路由會傳送 P 斷言身分識別與隱私權 ID 標頭。Direct Routing sends P-Asserted-Identity with Privacy ID headers.
  • RFC 4244針對所需歷程記錄資訊的會話初始通訊協定(SIP)延伸。RFC 4244 An extension to Session Initiation Protocol (SIP) for required History Information. 另請參閱:路由 SIP 通訊協定描述以取得詳細資訊。See also: Routing SIP Protocol description for more information.
  • RFC 3892會話初始通訊協定(依機構所參照)RFC 3892 The Session Initiation Protocol Referred-By mechanism
  • RFC 3891會話初始通訊協定(SIP)「取代」標頭RFC 3891 The Session Initiation Protocol (SIP) "Replaces" Header
  • RFC 6337優惠/答案模型的會話初始通訊協定(SIP)使用量。RFC 6337 Session Initiation Protocol (SIP) Usage of the Offer/Answer Model. 請參閱「RFC 差異」一節。See the “Deviations from RFC” section.
  • Rfc 3711rfc 4771RFC 3711 and RFC 4771. 使用 SRTP 保護 RTP 流量。Protect RTP traffic using SRTP. SBC 必須能夠使用 SDES 建立金鑰。The SBC must be able to establish keys using SDES.
  • RFC 8035RTP/RTCP 複用的會話描述通訊協定(SDP)提供/答案說明RFC 8035 Session Description Protocol (SDP) Offer/Answer Clarifications for RTP/RTCP Multiplexing

適用于支援媒體旁路模式之裝置的標準Standards applicable to devices that support media bypass mode

除了列為非旁路模式使用的標準之外,下列標準適用于媒體旁路模式:In addition to the standards listed as applicable to non-bypass mode, the following standards are used for media bypass mode:

可支援將位置資訊傳達給 E911 提供者的標準Standards applicable to support conveying location information to E911 providers

RFC 的差異Deviations from the RFC's

下表列出 Microsoft 在其中的 SIP 或媒體堆疊實現與標準偏離的 RFC 區段:The following table lists the sections of the RFC(s) in which Microsoft's implementation of the SIP or media stack deviates from the standard:

RFC 和章節RFC and sections 說明Description 差異Deviation
RFC 6337,區段5.3 保留並繼續媒體RFC 6337, section 5.3 Hold and Resume of Media RFC 可讓您使用 "a = 不活躍","a = sendonly",a = recvonly "保留通話。RFC allows using “a=inactive”, “a=sendonly”, a=recvonly” to place a call on hold. SIP proxy 只支援 "a = 非使用中",而且不了解 SBC 是傳送 "a = sendonly" 或 "a = recvonly"。The SIP proxy only supports “a=inactive” and does not understand if the SBC sends “a=sendonly” or “a=recvonly”.
在使用 c = 0.0.0.0 接收 SDP 時的 RFC 6337,區段5.4」行為RFC 6337, section 5.4 “Behavior on Receiving SDP with c=0.0.0.0 RFC3264要求工程師能夠接收連接位址為0.0.0.0 的 SDP,在這種情況下,這表示 RTP 和 RTCP 都不應傳送給對等。RFC3264 requires that an agent is capable of receiving SDP with a connection address of 0.0.0.0, in which case it means that neither RTP nor RTCP should be sent to the peer. SIP proxy 不支援此選項。The SIP proxy does not support this option.

操作模式Operational modes

直接路由有兩種操作模式:There are two operational modes for Direct Routing:

  • 在團隊用戶端、媒體處理器與 SBC 之間流動時,不需要媒體旁路Without media bypass in which all RTP traffic flows between the Teams client, the media processors, and the SBC.

  • 媒體旁路中,所有的 RTP 媒體都在團隊端點與 SBC 之間流動。With media bypass in which all RTP media flows between the Teams endpoints and the SBC.

請注意,SIP 流量永遠流經 SIP proxy。Note that SIP traffic always flows via the SIP proxy.