【文章內(nèi)容簡介】 nchronous Transfer Mode) transport ? physical layer is the interface to physical medium ?optical fiber ?radio link ?copper cable Iu CS CONTROL PLANE PROTOCOL STACK ? Control Plane protocol stack consists of RANAP, on top of Broadband (BB) SS7 (Signaling System 7) protocols ? The applicable layers are ? Signaling Connection Control Part (SCCP) ? Message Transfer Part (MTP3b) ? SAALNNI (Signaling ATM Adaptation Layer for Network to Network Interfaces) 註： SS7 ? MTP (Message Transfer Part，訊息轉(zhuǎn)送部 ) ? SS7的第一層為 信號數(shù)據(jù)鏈路 層 (Signaling Data Link Level)又稱為實(shí)體層 (Physical Level) ?定義信號鏈路之實(shí)體、電氣與功能，以提供實(shí)體鏈路收送 SS7信號 ? SS7的第二層為 信號鏈路 層 (Signaling Link Level) ?確保 SS7信號訊息在實(shí)體層上收送的 可靠度 ? SS7的第三層為 信號網(wǎng)路 層 (Signaling Network Level) ?處理信號訊息及管理信號網(wǎng)路 ? MTP3b ? 提供訊息繞送、識別，通訊裝置間的訊號鏈結(jié)管理、分享與轉(zhuǎn)換 ? SCCP：協(xié)助 ISUP做端對端之交換 ? 供 ISDNUP (ISUP)建立端對端的信號接續(xù) (Signaling Connection) ? 供網(wǎng)管、維護(hù)中心與各交換局間 (有 SP功能者 )建立信號接續(xù) ? 供將來用戶 (User)(如帳務(wù)中心 )與各交換局 (SP點(diǎn) )間建立信號接續(xù)，可直接傳送帳務(wù)資料，而不用再運(yùn)送磁帶 ? 供將來其他用戶部 (User Part)建立信號接續(xù)使用 ? TCAP ? 交易能力 (Transaction Capabilities； TC)或稱交易能力應(yīng)用部 (Transaction Capabilities Application Part； TCAP) ? 在 SS7網(wǎng)路中是屬於 應(yīng)用層 (Application Layer)中的一個應(yīng)用服務(wù)元件 (Application Service Element； ASE) ? 目的 ?提供 SS7網(wǎng)路中之信號節(jié)點(diǎn)對信號節(jié)點(diǎn)間 非電路接續(xù)相關(guān) 訊息的傳送 ?為它們之間的各種應(yīng)用提供一般性服務(wù) ?例如 ?交換機(jī)與交換機(jī)間非電路接續(xù)相關(guān)訊息的交換 ?交換機(jī)對網(wǎng)路服務(wù)中心資料庫作號碼翻譯 (例如 080服務(wù)號碼 )皆可由 TCAP所提供的服務(wù)來達(dá)成 ? SAALNNI is further divided into ? Service Specific Coordination Function (SSCF) ? Service Specific Connection Oriented Protocol (SSCOP) ? ATM Adaptation Layer 5 (AAL) layers ? SSCF and SSCOP layers ? designed for signaling transport in ATM works ? take care of signaling connection management ? AAL5 is used for segmenting the data to ATM cells 註： ? SSCF (Service Specific Coordination Function) ? 為特定服務(wù) 協(xié)調(diào) 功能 ? 包括 UNI (UsertoNetwork Interface)與 NNI (NetworktoNetwork Interface) ? 負(fù)責(zé)連線管理 (connection management)與鏈結(jié)狀態(tài)(link status)等管理 ? SSCOP (Service Specific Connection Oriented Protocol) ? 為特定服務(wù) 連結(jié)導(dǎo)向 通訊協(xié)定，提供 可靠的訊號傳輸服務(wù) ? 包括 流量控制 、 重送機(jī)制 、 連線控制 與 錯誤偵測 等 ? 透過 SSCOP傳送資料，如發(fā)生資料內(nèi)容錯誤，可透過重送 機(jī)制來修正錯誤；也提供上層通訊協(xié)定可靠的傳輸服務(wù) 註： ATM IN BRIEF 註： AAL2 AND AAL5 ? Above the ATM layer we usually find an ATM adaptation layer (AAL) ? AAL ? process the data from higher layers for ATM transmission ? segment the data into 48byte chunks and reassemble the original data frames on the receiving side ? Five different AALs (0, 1, 2, 3/4, and 5) ? AAL0 ?no adaptation is needed ? the other adaptation layers have different properties based on three parameters ?realtime requirements ?constant or variable bit rate ?connectionoriented or connectionless data transfer ? Iu interface uses two AALs ? AAL2 ?主要特色為 需要建立連線 (connectionoriented services)、 即時傳輸 (realtime data streams)及 非固定的傳輸速率 (variable bit rate， VBR)，適合用來傳送經(jīng)過 壓縮 的 影音 資料 ?每個經(jīng)過壓縮的影音資料傳輸速率並不固定，會隨著每個畫面的 複雜度不同 而有所改變，此類服務(wù)需要即時性傳輸，適用於 AAL2的傳輸服務(wù) ? AAL5 ?主要的特色為 無需建立連線 、 非即時傳輸 以及 非固定的傳輸速率 IU CS TRANSPORT NETWORK CONTROL PLANE PROTOCOL STACK ? Transport Network Control Plane protocol stack consists of ? Signaling Protocol on top of BB SS7 protocols for setting up ?AAL2 connections ( [ CS1]) ?adaptation layer ( [AAL2 Signaling Transport Converter for MTP3b]) ? BB SS7 are those described above without SCCP layer IU CS USER PLANE PROTOCOL STACK ? A dedicated AAL2 connection is reserved for each individual CS service ? Iu User Plane Protocol residing directly on top of AAL2 PROTOCOL STRUCTURE FOR IU PS Iu PS Control Plane Protocol Stack Iu PS Transport Network Control Plane Protocol Stack Iu PS User Plane Protocol Stack ? The following figure ? depicts Iu PS protocol structure ? a mon ATM transport is applied for both User Plane and Control Plane ? the physical layer is as specified for Iu CS IU PS CONTROL PLANE PROTOCOL STACK ? Control Plane protocol stack consists of ? RANAP ? signaling bearers ?BB SS7based signaling bearer ?an alternative IPbased signaling bearer ? SCCP layer is used for both bearer ? IPbased signaling bearer consists of ? M3UA (SS7 MTP3 – User Adaptation Layer) ? SCTP (Stream Control Transmission Protocol) ?designed for signaling transport in the Inter ?ensure reliable, insequence transport of messages with congestion control ? IP (Inter Protocol) ? AAL5 (mon to both alternatives) 註： ? SCTP (RFC 2960) ? 提供 可靠的傳輸 服務(wù)，主要存在於IuPS介面 ? 運(yùn)作於完整的 IP網(wǎng)路環(huán)境中，並可適用於 IPv4與 IPv6 ? 提供 流量控制 、 重送 機(jī)制，以供上層 M3UA一個穩(wěn)定可靠的傳輸介面 ? M3UA ? 基於 SCTP，提供上層 SCCP訊號傳送機(jī)制 ? SCCP ? 原本以 MTP3作為它下層的通訊協(xié)定 ? 為順利透過 IP或 ATM等通訊協(xié)定，在其下層提供一個類似 MTP3的通訊協(xié)定，以便順利運(yùn)作在這些通訊協(xié)定上 ? RANAP ? 本身並無處理錯誤能力 ? 它假設(shè)所有送出的訊息都會被正確接收，即其下層通訊協(xié)定 (Transport Network Layer)需有 處理錯誤 能力 ? 如 SSCOP與 SCTP具有 錯誤偵測 與 資料重送 機(jī)制 IU PS TRANSPORT NETWORK CONTROL PLANE PROTOCOL STACK ? Transport Network Control Plane is not applied to Iu PS ? Setting up of GTP tunnel ? requires an identifier for the tunnel and IP addresses for both directions ? these are already included in RANAP RAB Assignment messages IU PS USER PLANE PROTOCOL STACK ? Iu PS User Plane ? multiple packet data flows are multiplexed on one or several AAL5 PVCs (Permanent Virtual Circuit) ? GTPU (User Plane part of GPRS Tunneling Protocol) is the multiplexing layer that provides identities for individual packet data flow ? each flow uses UDP connectionless transport and IP addressing RANAP PROTOCOL ? RANAP ? defines interactions between RNS and CN ? the signaling protocol in Iu that contains all the control information specified for Radio Network Layer ? implemented by various RANAP Elementary Procedures (EP) ? each RANAP function may require execution of one or more EPs ? three classes of EP ?class 1 EP ?request and response (failure or