OCS 2007 進階系列 建置高品質之 OCS 2007 VoIP David Feng 馮立偉 台灣微軟 OCS 特約講師

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 VOIP 規劃技巧

產品總覽– Media Microsoft® Office Communications Server 2007 提供即時及排程聲音及影像會議 Microsoft® Office Communicator 2007 提供豐富多方 聲音/視訊會議 Microsoft® Office Live Meeting Console 伺服器或服務型式之援 Web/視訊語音會議

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 OCS 2007 VOIP 部署規劃技巧 Q/A

現金商業環境 VOIP 需求 企業客戶告訴我們甚麼 員工 媒體品質跟使用性可重要 在哪使用都要有一樣的使用經驗 IT 決策者 提供不只是省錢而已 需要有更彈性的決策空間 IT Professionals 跟現行網路架構結合 容易且快速的部署

傳統 IP 電話限制 普及化 複雜度 不完整 越來越多人行動辦公 傳統 QoS/CAC 方法複雜 且難管理 管理者無法有效管理所 有網路 大部分使用者抱怨的都是語音品質 許多因素影響語音品質 7

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 OCS 2007 VOIP 部署規劃技巧

確保高品質使用經驗 (QoE) 設計適合 IP 之媒體平台 訂定適合之網路 大小 良好的測量

確保高品質使用經驗 (QoE) 設計適合 IP 之媒體平台

針對 Internet 設計 面臨之挑戰 解決方案 效益 遺失, 抖動, 延遲, 連線, 安全性, 等等... 管理者無法掌控所有點對點網路 運用先進軟體打造智慧型端點 效益 允許新的使用情境如行動工作者, 跨公司使用 如果一個解決方案能在 Internet 上使用, 那麼一定可以用於 Intranet

傳統 VoIP 的限制 傳統 IP 電話不是針對 IP 網路設計 Circuit switched 傳輸技術 脆弱的編碼器, 對網路狀況非常敏感 “被認為是收費水準的 G.711, 即使1% 遺失也可以嚴重造成使用者經驗的降低1 “預設的 G.729 編碼器要求封包遺失至少要低於 1% 以避免音訊的錯誤”2 需要藉由網路工程及設備投資改善整體成效 1 - Intel: Overcoming Barriers to High-Quality Voice over IP Deployments 2 - Cisco: Quality of service for Voice over IP 12

微軟媒體平台 強化之 audio/video 處理 Forward error correction and error concealment Time-warping jitter buffer control Dynamic Adaptation to real-time network conditions 最佳化封包內的音訊 Noise suppression Automatic gain control Acoustic echo cancellation 先進的網路層 NAT/Firewall traversal Secure RTP 測量及回報使用者經驗

對抗封包遺失 RTP / RTCP 1 4 2 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 FEC 5

微軟即時編碼器 RTAudio and RTVideo 支援寬頻音訊 寬頻大幅改善通話的自然性即可辨識性 高話質電話經驗 對抗遺失及抖動 內建自動修復的保護機制 高效率使用頻寬 比傳統 VoIP 編碼器在低頻寬下提供更高 的解析度 多重速率編碼器 允許即時改變 Codec Bandwidth RTAudio (8kHz) 11.8 Kbps RTAudio (16kHz) 29 Kbps G.711 64 Kbps

解決根本問題 網路或 payload 問題 網路影響 使用應用層智能解決這些問題 Devices, ambient noise, echo, lack of gain… Payload effects are end-to-end Often most detrimental but least managed Network can be perfect but call unacceptable Microsoft UC uses AEC, NS, AGC to normalize 網路影響 Multiple dynamic error correction mechanisms, dynamic automated adaptation to actual network conditions, bandwidth (BW) elasticity 使用應用層智能解決這些問題 16

Quality of Experience 比一比 Subjective perceptual experience Mean Opinion Scores Source: benchmarking study performed by Psytechnics Ltd in December 2006 17

聲音品質比一比 “The ripe taste of cheese improves with age. Act on these orders with great speed. “ 編碼器 完美網路 10% 封包遺失 G.711 G.729 RT Audio Narrowband

確保高品質使用經驗 (QoE) 設計適合 IP 之媒體平台 訂定適合之網路 大小

頻寬需求 這些是單向 “on the wire” 數字 靜音節省更多頻寬 根據使用量動態調編碼器 Codec 11/14/2018 6:31 AM 頻寬需求 Codec Payload Bit Rate IP + UDP + RTP + SRTP RTAudio (8kHz) 11.8 Kbps 32.6kbps RTAudio (16kHz) 29 Kbps 49.8 kbps Siren 16 Kbps 40.4 kbps 這些是單向 “on the wire” 數字 靜音節省更多頻寬 根據使用量動態調編碼器 Microsoft Confidential - FTE only - not for customer use © 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

澄清重點 這些是 ‘尖峰時間’ 頻寬數字 2 方通話在頻寬上來說是對稱計算 會議也是對稱計算 影像頻寬 > 音訊頻寬 任何模式依據於假設 考慮你辦公室之間互 call 狀況 站台間有多少通電話, 多少會議 ? 注意以下的需求 CEO 想要召開全公司視訊/語音會議 ?

媒體優先順序 Microsoft® Office Communications Server (OCS) 2007 支援 DiffServ 環境 設定媒體流量優先順序在連線上將容易造成壅塞 DSCP marking by the end-points Audio: Expedited Forwarding Video: Class 3 of Assured Forwarding (optional) Limit prioritized traffic to 33% of capacity 針對 UC 裝置考慮使用 VLAN Ease trust issue and helps with IP expansion 中央控管群組原則 22

其他網路考量 延遲 遺失 抖動 ITU-T G.114 recommendations for mouth to ear latency 11/14/2018 6:31 AM 其他網路考量 延遲 ITU-T G.114 recommendations for mouth to ear latency < 150 ms is excellent > 250 ms is problematic > 400 ms is unacceptable TIA-920 recommendations for wideband VoIP devices Network latency should be <50 ms to achieve <150 m2e latency 遺失 Up to 10% random loss can be handled without problems 抖動 Up to 30ms loss can be handled without significant problems Microsoft Confidential - FTE only - not for customer use © 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

網路考量技巧 依據使用模式了解網路頻寬需求 逐步增加 UC 啟動之使用者 可用頻寬不是全部拿來做語音的 漸進式調整使用模式. 然後在每一階段驗證

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 OCS 2007 VOIP 部署規劃技巧

確保高品質使用經驗 (QoE) 設計適合 IP 之媒體平台 訂定適合之網路 大小 良好的測量

Quality of Experience Microsoft Unified Communications (UC) 獨特提供一個完整, 豐富解決方案給 QoE Enterprise Voice, 不需要使用 QoS, 再任何網路, 任何時間, 任何地點 完整, 使用者導向的品質解決方案 Centered on users, incorporating all significant parameters of user experience 智慧型端點裝置 Endpoints with real time capability to monitor, pilot, optimize, and deliver UC QoE 即時收集真實使用經驗數據 Measuring, quantifying, and monitoring the user’s subjective experience Media stack 最佳化給 unmanaged 網路 Rich application that takes real-time adaptive and corrective actions to continuously optimize the user’s subjective experience on any network 27

QoE Monitoring Server 針對每通電話或會議建立call data record (CDR) Metric CDR 包含 MOS metrics 資料 網路數據 總共會有高超過 30 項數據會影響品質 紀錄可以被轉到 QoE monitoring 或是 third-party server Server 蒐集這些資訊 提供報表介面及執行資料分析 有限的網路層分析 28

Office Communications Server 2007 品質經驗 (QoE) 監控 每個 session 中每一個端點產生細部 QoE 報表 Server 收集報表並產生警示及高階報表 利用這些報表 找出趨勢及問題點

QoE 報表資訊收集 Mediation AV MCUs servers PSTN Network At home Corp Internet QoE Server Reporting Console Off “corp” MOM At work

收集數據範例 Audio QoE Perf counters Additional counters Some video counters Listening MOS, Conversational MOS, Network MOS Classify calls to detect quality degradation Additional counters % calls with poor jitter factor % calls with poor packet loss factor % calls with high delay % calls with failed media connectivity Some video counters % calls with low video bitrate % calls with high video packet loss 3/20/2007 9:43:24 AM TUK-LSMS-02.exchange.corp.micr sip:warrenba@microsoft.com;opa 3397 3.72000002861023 3.72000002861023 4/3/2007 12:15:22 PM sip:jingyuq@microsoft.com;opaq sip:warrenba@microsoft.com;opa 1320 4.07999992370605 3.71000003814697 2.29999995231628 1.10000002384186

QoE Monitoring 情境 使用者 接近即時監控 品質經驗驗證 VoIP 規劃 Tier 1: Help desk Tier 2: NOC Tier 3: Network Engineering 接近即時監控 Alerts when VoIP quality degrades Health Model provides an overall view View a user’s quality history at any time Proactively identify worst performing endpoints Microsoft Operations Manager MOM Pack 品質經驗驗證 Verify media quality at each stage of your rollout Use MOS to set up QoE based SLA agreements Identify the QoE levels by location VoIP 規劃 Right provision your network for QoE Watch out for QoE hotspots Identify QoE trends

每通電話核心數據 SIP Session data Capture / Render device Endpoint IP address/mask Inside/outside user flag ICE Connectivity Path Codec(s) Capture / Render device Noise Level / Signal Level Packets / Packet loss rate Jitter / Round Trip Time Latency Burst Conversational MOS Listening MOS Sending MOS Network MOS / Network MOS Degradation

主要功能 A/V Quality Metric Reports Instrumentation and Alerting Quality reports collected at the end of each call From Office Communicator, IP Phone, Live Meeting client, A/V Conferencing Server, Mediation Server Reports aggregated and stored into DB User Perception Payload Effects Network Effects Instrumentation and Alerting Statistical based performance counters for Network factors Grouped by Location, A/V Conferencing Server, and Mediation Server. A Location is one or more subnets Instrumentation is consumed by MOM Pack for alerting Out of the Box Reports SQL Reporting Services Report Pack Scenario based reports (PC to PSTN, PC to PC, Conference) QoE Summary, Trend, Worst Performing Endpoints Additional reports Call List Report Call Detail Report Server Health Report

Flexible report filtering 內見報表範例 Reports QoE Summary Report QoE Trend Report Worst Performing Endpoints Report Call List Report Call Details Reports Flexible report filtering Time Connectivity type Call types Thresholds Endpoints Location Endpoint type

demonstration QoE Monitoring Server

QoE Monitoring Server 結合 Operations Manager Pack

有關 MOS 分數 寬頻 vs. 窄頻 MOS Listening, Sending, Network MOS is reported on a Wideband scale Conversational MOS on narrowband Be aware of scale when comparing to other vendors MOS scores Payload MOS (Listening, Sending, Conversational) are not useful per call, only in aggregation For MOS, need to compare similar scenarios

重要 QoE 觀念 QoE monitoring 在以軟體驅動的 VoIP 環境扮演重要角色 Microsoft QoE 解決方案提供 接近即時監控 歷史報表 每通計算通話數據 運用科學方法計算數據 Microsoft QoE 解決方案可以跟 OCS 2007 結合運用而不需要額外設定  39

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 OCS 2007 VOIP 部署規劃技巧

調整好你的網路 每個 clients 都會使用頻寬 不管是建立 VoIP 電話或 audio/video 會議, 你都已經增加了服務在你現有網路上 實施控管原則在網路層或是在你控制的 Client 電腦上

到底使用多少頻寬 ? 這些是實際在網路傳的數據, 不是 raw data 這是單項數據 Codec Min Bandwidth Max Bandwidth Realtime Audio (RTA) 24 Kbps 45 Kbps Siren 48 Kbps Realtime Video (VC-1) 50 Kbps 250 Kbps 這些是實際在網路傳的數據, 不是 raw data 這是單項數據 數字是在最差狀況下的估算 – 靜音狀況下可以省更多頻寬 封包化會依據使用量動態調整, 因此可以節省更多頻寬

每人使用量計算 Type of usage is important when planning Media Type Bandwidth Needed Audio 45 Kbps Video 250 Kbps Data ~45 Kbps Signaling 10 Kbps Total 350 Kbps per direction Type of usage is important when planning Stack will adjust to available BW every five seconds Consider the whole path end-to-end

其他網路考量點 延遲 遺失 連接性 Engineer to less than a mean of 150 milliseconds Up to 10% can be handled without significant problems 連接性 The clients can connect through nearly all common networks

管理使用量- 伺服器 伺服器原則 限制可以被召開的會議種類 舉例 : 只有聲音的會議 現制誰能召開會議即可以允許多少人參加

管理使用量- Client Client policy Limit the bandwidth used HKLM\software\policies\Microsoft\LiveMeeting\ MaxAudioVideoBitrate HKLM\software\policies\Microsoft\Communicator\ Global setting per application Specific the ports Limit the range of ports used by Audio and Video through policy

支援 DiffServ Microsoft UC 不需要 Differentiated Services (DiffServ), 但 可以跟 DiffServ 環境一起運作, 並支援 DiffServ marking Differentiated Services Code Point (DSCP) marking by the endpoints By default, endpoints mark all media for DiffServ Audio: Expedited Forwarding Video: Class 3 of Assured Forwarding DSCP marking 藉由原則調整 Windows Vista™ 允許中央統一強制套用原則 47

議程大綱 產品總覽 - Media VOIP 面臨之挑戰 微軟 Quality of Experience (QoE) 技術 Quality of Experience Monitor Server 調整你現有網路 OCS 2007 VOIP 部署規劃技巧

重要部署技巧 Microsoft® Office Communications Server (OCS) 2007 支援智慧型媒體端點 成功部署關鍵 確認及調整網路 管控使用性 計算效能指標 逐步擴增

規劃流程 Key Considerations Topology Selection Fill-out Capacity model Verify model assumptions Run model Confirm output topology Prepare for Deployment Start Deployment

重要考量因素 功能需求確認 站台分析 部署途徑 你會部署語音嗎 ? 你會部署影像嗎 ? 你會部署會議功能嗎 ? 你需要在企業外面使用這些功能嗎 ? 你需要 IM 及會議稽核功能嗎 ? 站台分析 你需要多少個站台 ? 每一個站台有多少可用頻寬 ? 每一個站台有多少使用者 ? 每一個站台的可用度需求為何 ? 部署途徑 你是從 LCS 2005 升級上來 ? 這是一個 Greenfield 部署嗎 ? 這是一個 proof-of-concept 部署嗎 ?

拓樸選擇 Small Branch or Proof of Concept No No Yes Yes No Regional HA? > 5K users Small Branch or Proof of Concept No No Standard Edition Yes Yes > 30K users No Enterprise Edition: Consolidated Regional Datacenter Yes Enterprise Edition: Expanded Central Datacenter

拓樸選擇 Global or regional? Enterprise Edition Expanded 可以延展到 Global 然而, Mediation Server 要接近 IP-PSTN gateway Front-Ends 及conferencing servers 不能在一個集區中分屬在不同區域中 使用者及集區間網路延遲應該要低於 150 ms 因此 你可能需要部署 regional 資料中心提供影像/聲音或 資料會議

網路考量點 在 Audio/Video 上停用 IPSec Audio/Video 點對點延遲最高150 ms 通話中靜音可節省頻寬 根據網路使用狀況動態調整頻寬 Media Bandwidth (on the wire) Audio 50 Kbps per media stream (one-way) RTAudio (8kHz) 32.6 Kbps RTAudio (16kHz) 49.8 Kbps Siren 40.4Kbps Video 300 Kbps per media stream (one-way) Data Collaboration 112 Kbps (full desktop sharing) Negligible for slide presentations, etc

Simple Model For 2 Party Call 50% of time User A talks 50 kbps sent from SF to NY 50% of time User B talks 50 kbps sent from NY to SF Average this out for N concurrent calls Total BW SF to NY = N X 25 kbps Total BW NY to SF = N X 25 kbps SF NY User A User B

規劃階段性部署 100% users fully UC enabled busiest hour Use Population SF Office (OCS Pool) 750 NY Office (WAN link) 250 Bandwidth Requirements (BHCA) – 2 Party Calls BHCA SF-NY 25 Calls Answered 22.5 Audio (Mbps in each direction) 0.55 Video BW (Mbps in each direction) 1.37 User Model Answered Calls: Total Calls 0.9 Audio: Audio + Video Calls 0.75 Bandwidth Requirements – Conferencing Conference Audio SF -> NY (Mbps) 0.49 Conference Audio NY -> SF (Mbps) 0.60 Conference Video SF-> NY (Mbps) 1.53 Conference Video NY -> SF (Mbps) 0.38 Conference Model Peak Concurrent Conference Users 50 Avg. Meeting Size 8 Audio : Audio + Video Confs 0.5 Peak Bandwidth Requirements –Total Total SF -> NY (Mbps) 3.94 Total NY -> SF (Mbps) 2.36

總結 天下沒有白吃的午餐– 新的服務一定會占據頻寬 Microsoft UC Quality 是一個完整的解決方案結合可變式端點技術在所有的通訊過程中計算使用經驗, 以及一個先進的 media stack 可以修正網路及非網路上的音質損害 Microsoft UC 在應用層管理流量及品質而非網路層, 同時不需要 QoS 或 CAC; 它可以運作於 QoS 啟用之網路及支援 DiffServ 良好的網路架構及調整仍然很重要 Microsoft UC 重點在提供最佳化品質於任何網路, 任何時間, 任何地點 57

Resources Windows Vista QoS Psytechnics report Microsoft UC Info www.microsoft.com/technet/network/qos/default.mspx Psytechnics report www.psytechnics.com/site/sections/news/2007/2007_03_06.php Microsoft UC Info www.microsoft.com/uc/default.mspx