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Data, Voice, and Video Convergence on Higher Education Networks Jim Jokl [email protected] August, 2000 The Traditional Campus Network Model Telephone service » Manages PBX or Centrex, cable plant » Usually self-funded via chargeback Data network service » Typically part of computing center » Funding models vary widely Video services » Often distance learning office » Funding sources? The Converged Multiservices Campus Network Model Single data, voice, and video infrastructure service Implications: » Technical » Organizational » Financial » Staff retention and training Standard Network Applications Normal services » Web » Email » Remote login » File and print services These applications function well with a best effort network data delivery model Newer Converged Network Services Video Streaming Video Conferencing Telephony These applications function best with a guaranteed network data delivery model Network Capacity for Video Percent of Standard Ethernet 80 60 NetMeeting VCON MPEG2 (a) MPEG2 (b) Percent 40 20 0 Method Broadcast Network Video Applications » Major events & lecture style classes Infrastructure needs » Low loss, high capacity, multicast Systems » Real Networks » Windows Media » Many others On-Demand Network Video Applications » Case materials, training, time shifting Infrastructure needs » Low loss & high capacity Systems » Real Networks » Windows Media » Many others Videoconferencing Applications » Seminar style classes » Travel avoidance Infrastructure needs » Low latency, low loss, high capacity Systems » NetMeeting » VCON, PolyComm » Many others Videoconferencing: Multipoint Service Video Video Unit Unit Network MCU Video Video Unit Unit Multi-location sessions Local and remote sites Video follows speaker (and not) Products from Cisco, Radvision, White Pine, many others Videoconferencing: ISDN Gateway Service Video Video Video Unit Unit Unit Access legacy systems Translates: » H.323 <--> H.320 Campus Network ISDN Gateway Remote Systems Applications: » » » » Interviews Guest speakers Negotiations Collaboration Packet Voice: What is different? Traditional Phone Switch PSTN PSTN Phone Phone Switch Voice over IP (VoIP) Phone Call Manager Gateway Campus Network Routers, hubs, switches Phone Phone Phone Phone Network Capacity for Packet Voice Services 100 90 0.6 80 0.5 70 60 0.4 50 0.3 40 0.2 30 20 0.1 10 0 0 G.711 G.726 G.728 G.729 Voice Codec Type G.723.1 G.723.1 Subjective Voice Quality (%) % of Ethernet Required 0.7 % Ethernet % Quality VoIP Systems: Lots of definitions PBX VoIP line or trunk card » Call path between IP phones via PBX » Initial releases by Lucent, NEC, others PBX VoIP line or trunk cards » Call path between IP phones via LAN » Nortel, Siemens, others have systems » Most PBX manufacturers working towards this type of functionality Major advantage: phone features VoIP Systems Definitions Continued LAN-based Systems » Call setup via LAN call processing server » Call path between all peripherals via LAN » Cisco Call Manager » Siemens HiNet Xpress » Others LAN-based systems generally limited » ACD, console, call center applications Some VoIP Applications Toll bypass » Low risk » Potentially limited payback Telecommuting » Phone # tied to phone - not wall jack » DSL or cable modem connection On-campus telephone replacement » Converged network - many opportunities and issues to consider Selected Campus VoIP Issues E911 » Phone # tied to phone - not wall jack » PC-based soft phones Electrical power and cooling » Phone instruments » Wiring closet UPS units and cooling Network security Privacy Number plans SIP and H.323 H.323 Protocol » ITU protocol Session Initiation Protocol (SIP) » IETF developed as alternative to H.323 » RFC-2543 Support for Converged Applications Traditional data applications Voice » Low latency, loss, jitter Streaming Video » Low loss and high capacity Videoconferencing » Low latency, loss, jitter » High capacity A Campus Network Building LAN Building LAN PC PC PC Video Building LAN Backbone Network Building LAN Building LAN PC Server Building LAN Appliance PC Standard Ethernet: Intra-Building Network B Access Mechanism » CSMA/CD C E » 10 Million bits/sec » 1 million chars/sec F A D Speed Bandwidth shared Applications » Email, Web, telnet, directory, printing, file systems, etc 100 Mbps Switched Ethernet Intra-building Network Network Switch E B » 100 Million bits/sec » 10 million chars/sec C A D Speed Bandwidth additive Applications » Email, Web, telnet, printing, file systems, video, voice, etc F May support Converged Net - even at 10Mbps Network Quality of Service (QoS) Goal: provide better service for some Characteristics of QoS » provide guaranteed or priority delivery » minimize delivery delay » minimize delay variations » provide consistent data throughput capacity QoS: Some Mechanisms Overbuild the network RSVP - reserve network capacity » Applications request QoS services » Network says yes/no – Policy – Available resources – Network busy signal » State maintained at each network hop » Relatively complex QoS: Some Mechanisms Per-hop mechanisms » Precedence bits in IP TOS byte » Differentiated Services - RFC-2475 – Traffic classified as it enters the network – Per-hop behavior based on classification – All state is in the packet header – Framework for how to cross admin boundaries » Relatively simple QoS: Some Mechanisms Layer 2 Mechanisms » 802.1Q - VLAN Tagging » 802.1p Class of Service field of the 802.1Q tag Implementation » Queue management » Packet scheduling IP Phones and QoS Switched Network Wall Jack IP Phone Personal Computer IP phone generates 802.1p CoS = 5 and IP precedence = 5 Switch in phone can clear PC’s QoS header settings Different VLANs for phone and PC Multicast Support Video Server LAN Switch PC Hub P1 P2 PC PC Backbone Network P3 PC PC Building LAN Building LAN Building LAN P4 Building LAN PC Building LAN PC Network Reliability What about all of those 9s? PBX: 99.999% uptime » Down 5.25 minutes/year Is your data network ready to support life safety applications? Network Management Redundancy Response time and coverage Converged Networks Infrastructure Summary Consider wiring closet switches with » 10/100 Mbps » 802.1p and 802.1Q support » IGMP snooping Support QoS mechanism in network core Support multicast in network core Wiring closet UPS power and cooling? Management for network availability Different response times and service levels? Wireless Communication Promise of the future Convergence » Voice, data, video, applications Integration Ubiquitous access New wireless technologies will address much » but be careful of the hype Wireless Technology by Coverage Area Personal Area Networks » Microcellular » 10 meters to 200 meters Cellular » » 10 cm to 10 meters Large and small cells Hundreds of meters to miles Long distance Personal Communication Services (PCS) Targeted Services » » » » » Cellular telephone users Paging Short Messaging Service (SMS) Nation-wide services Some technologies: modem-speed data PCS Technology Cellular: varies but can be miles Microcellular within buildings 1.9 GHz band (licensed) Digital transmission Embedded devices: phones, PDAs, etc PCS Technology CDMA (Sprint, PrimeCo, Intelos) » » » Voice, text messaging, paging Low-speed data Hospital power levels TDMA (SunCom, AT&T) » » » Voice, text messaging, paging Data harder to handle High-power hand sets Wireless LAN Systems IEEE 802.11 Targeted Services » » » » » Notebook PC users and PDAs Hard to wire locations Changing environments Temporary networks Campus-wide networks Wireless LAN Systems IEEE 802.11 Technology (now) » » » » » Microcellular (250 to1,200 feet) 2.4 GHz band Speed: 1 to 11 Mbps Power: 100 mW Privacy: inherent and WEP Technology (future) » » 802.11a @ 5 GHz Speed: 6 to 54 Mbps Wildcard: Bluetooth Personal Area Network Targeted Services » » » Wireless headset / speakerphone Synchronization of PDAs, notebooks, phones Cable elimination Speed around 721 kbps + voice 2.4 GHz band Wireless Convergence Data on wireless voice network » Modem-speed data via PCS » Messaging, WAP, PCS » Soon to be much faster Voice on wireless data network » Symbol » SpectraLink Opinion: the biggest challenge to LANbased VoIP - one phone, one number Organizational Issues Integrated data, voice, video groups Departmental LANs vs Enterprise Networks Staff development and training Soft VoIP phones and desktop mgmt? Wireless Interference » » Between unlicensed services Between central and departmental systems Converged Network Costs Will vary widely by campus Consider: » » » » » Wiring closet UPS power Additional wiring closet cooling Edge 10/100 switches with 802.1p and Q A new network core Increase network support - life safety VoIP » Equipment - not 2x PBX Financial Models Converged networks, especially VoIP, break most existing funding models What to bill for » » » » Wall outlet? MAC Address? IP phone or soft phone? A tax based on headcount or NASF? Go for broke: central funding? Summary: Items to consider Solve organizational issues » » » » » Integrate central data, voice, and video staff Resolve ownership of building LANs “Ownership” of campus wireless spectrum Who gets benefits from easements? Pay special attention to staff Pay attention to network technology decisions Find a long term financial model Summary: Items to consider Socialize the issues now Don’t promise to save money » » » Toll bypass MAC work Sell the network on its new services Make a wireless decision Upgrade your network » The killer application will come Observations, questions, issues?