Optimizing the Internet Quality of Service
and Economics for the Digital Generation
Dr. Lawrence Roberts
President and CEO,
lroberts@anagran.com
Original Internet Design
File Transfer and Remote Computing main activities
Constrained by high cost of memory
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Only Packet Destination Examined
Packet Loss Tolerated (Small Buffer Size)
No Flow State Memory
ARPANET 1971
No Source Checks
No QoS
No Security
Best Effort Only
Slow Rates
Copyright Anagran 2006
Planned Use of Internet
Voice –
Totally moving to packets – Low Loss required
Video -
Totally moving to packets
– Downloads – Needs Faster File Transfer
– Broadcast – Needs Fast Guaranteed Rate Path Setup
Emergency Services –
No Preference Currently
– Who gets service when capacity limited
Presence –
GPS aware of and effecting environment
Rapid Response Tasks
– Financial Transactions – time is money
– Remote Control – Games, Avatars
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Change Is Required
No provision for low loss streaming media
– Cannot determine if valid path exists
– Cannot insure quality (loss, delay, jitter, rate)
– Need Preference for streaming media (who gets it)
File Transfer much too slow and inefficient
Cost growing as traffic grows – Correction needed
– Traffic growing faster than Moore’s Law - % GDP an issue
Fairness required – P2P can swamp other users
Security must be improved
Delay must be reduced for rapid response
Copyright Anagran 2006
How to Fix The Internet
Manage Quality and Routing of Flows, not Packets
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Flows can be managed individually – QoS and route
Flow State Memory now economic after 40 years
Keeping Flow State avoids routing all packets, reduces cost
High packet loss avoided for both files and streams
Vastly improved traffic management – avoids over-capacity
Load can be balanced over all network paths
Fairness can be achieved, rates can be service dependent
Delay in microseconds due to controlled load, little buffering
Security – DDOS can be prevented, Authentication improved
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Buffers Add Delay and Jitter
Packet Router
Route
Big
Output
Buffer
Switch
Major Cost
Major Delay
Discard
Output
Input
Flow Router
Load
Controlled
at Inputs
Route
Switch
Load M
easure
Flow State
Load
Controlled
at Output
Discard
ment
No Delay
Output
Input
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Where Flow Routing is Needed
Server Farm
FFR
FFR
ISP
Control P2P, Fairness
No Loss Video & Voice
FFR
FFR
LAN
FFR
FFR
FFR
FFR
FFR
ISP
Network
Core
DSL
EDGE
Control P2P, Fairness
No Loss Video & Voice
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No TCP Sync Loss
CAC Video & Voice
WiFi Mesh
FFR
Eliminate Packet Loss at Server Farm
TCP
Packet Routers under Overload Drop 30-50% of Traffic,
Flows Synchronize – Output Oscillates
P a c k e t Ro u t e r - W RED - 2 :1 O v e r lo a d
100%
75%
50%
25%
0%
520
1,0 2 0
Flow Routing under Overload Drops 1-2% of Traffic
Independent Discards avoid Synchronization, Fairness
F lo w R o u te r - IF D - 2 : 1 O v e rlo a d
100%
75%
50%
25%
0%
800
900
10 0 0
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110 0
12 0 0
13 0 0
14 0 0
15 0 0
16 0 0
Flow Discard for Video and Voice
UDP
Packet Routers Drop Packets – All 6 TV Programs Ruined
Flow Routers Drop Flows – Five TV Programs Perfect, One
Dropped
Example of DSL that has the capacity for 5 TV programs, but 6 are requested
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Fairness and Flow Classification
Flow Rates need to be controlled
Flows can be classified using;
– Deep Packet Inspection – Costly, Change or Encryption foils it
– Classify flow based on Rate, Bytes, Time, Packet Size
• Flow Router can do this at full rate
• Class Identification
File
Transfer
• Fairness/Class
P2P using WRED
500
450
400
Rate
(Kb/s)
350
300
P2P controlled to Fair Rate
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200
150
HTTP
100
Skype
50
0
0
0.5
1
1.5
2
VoIP
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2.5
3
3.5
Time (Minutes)
4
4.5
5
5.5
Dimensions
• Rate
• Total Bytes
• Total Time
• Packet Size
• Port
• Protocol
• DiffServ
Controls
• Rate
15
• Priority
00
12
50
• Delay Var.
10
00
e • Loss Rate
75
z
0
i
50
0
t S s)
25
e
0
0
ck yte
6
a
P (B
Flow Routing at the ISP Edge
DSLAM’s
L3 Packet Routers
Content Sources
• Text
• Images
• Video
• Voice
Flow Router
CORE
METRO
EDGE
WiFi Mesh
Flow Router
Rate control insures fairness and no P2P overload
High quality delivery of IPTV & VoIP; delay and jitter controlled
Multiple SLA’s can be supported and reported
DDoS attack identification and protection
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End-to-End QoS Signaling in ITU
Y.flowreq is a flow based, in-band signaling standard
– Nearing completion in ITU SG-13, then SG-11
– For File Transfer – Max Network rate negotiated
– For Streams – Path setup at rate with low loss, jitter
• Immediate determination of path availability
• User Preference Priority used if capacity limited
– In-band signaling insures full scalability to all flows
– User Authentication to insure per flow security
– Tunnel Capability allows Virtual Private Networks
• Fully Scalable, Low OPEX, Guarantees available
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Y.flowreq Impact on File Transfer
Minutes to Download a 1 Hour Video
Vidio File of 1 hour at 4 M bps over 100 Mbps channel with 1% packet loss
1,000
IP QoS
TCP
100
Minutes
1 Hour
10
3 Minutes
1
10
100
1,000
10,000
Distance - Miles from source
Video-On-Demand uses TCP to deliver very large files which would take very long
times with standard TCP, whereas QoS Signaling can maintain full rate cross
Copyrightcountry
Anagran 2006
IPTV Path Reservation
A critical requirement for streaming IPTV (Sports, News, etc.) is to:
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Determine if a path exists with sufficient bandwidth for a request
To route the Video over that path with low delay variance & low packet loss
The ITU QoS Signaling finds and reserves the path if there is one
This is the only technique that can do this at line rate and scale to any size deployment
S IP R
e
In-Band QoS Request
Policy
Server
p o n se
1
es
R
.
t
s
e
qu
Request 4 Mbps
3
4
DSLAMs
2
Video Request
Call Acceptance Response
4 Mbps Accepted
Needed in IMS, RACF, and all similar IPTV setup protocols
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Content
Servers
Preference Priority – Who gets the capacity?
Preference Priority was in the telephone network
It never has been in the Internet
With fixed rate streams it is critical – In Overloads:
– Emergency Services and Military
– Priority for the office – who gets through
– Priority for the home – who gets the 2 video streams
ITU Y.flowreq includes preference priority
For fixed rate flows, the lowest priority may get blocked
For file transfer, the lowest priority may get a lower rate
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Security – Flow Authorization
Today routers don’t even check the source address
– Anyone can claim to be anyone else
ITU Y.flowreq has a high security Authorization
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The user logs into the network identifying himself
The network checks his billing, QoS priority, and preference
The user is given a crypto token with a time limit
Each flow is then authorized by the token
The user receiving the flow can also reject any flow
Helps control SPAM, viruses, worms and DDOS attacks
Also insures user has the authority claimed
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Internet Economics
Generally the Internet traffic doubles each year
Router cost drops with Moore’s Law: ½ every 18 mo
This means the cost of the Internet doubles every 3 years
The cost can only be kept in check by major redesigns
Flow routing with an optical core can cut the cost 16:1
– That eliminates 12 years cost growth (4000 times the traffic)
– Savings are through
• Lower cost systems, flow and optical
• Higher utilization
• Direct lambdas or tunnels between city pairs – Route 1.3 times/flow
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Conclusions
The Internet was not designed for Voice, Video, etc.
The current packet router design must be changed
Flow routers solve many of the current shortcomings
Delay, jitter, loss, and cost all vastly improved
Also needed is end-to-end QoS in-band signaling
The ITU’s Y.flowreq permits many additional capabilities
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High Speed File Transfer – up to 100 times faster
Deterministic, scalable, fast video and voice stream setup
Higher security with flow authorization
Tunnels permitting simple guaranteed VPN’s
Copyright Anagran 2006