Transcript SAC Conference Tutorial

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?