QoE as a key driver for network

evolution path in All-IP scenario

Daniele Roffinella & Lorenzo Santilli

Telecom Italia

5G World Summit 2016 - London, 30th June 2016

2

The rise of the All-IP world

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All Applications & Services will be «IP-based»…

…the IP Traffic will constantly grow…

Exabytes / Month

Cisco VNI Global IP Traffic Forecast

… and most of the IP traffic will be video

The sum of all forms of video (TV, video on demand, Internet,

P2P) will be in the range of

80% to 90% of global consumer traffic by 2018

Cisco “The Zettabyte Era”

3

Telcos are investing a lot to increase speed on Fixed…

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t

2012

Performance

2,5/1,25 Gbit/s shared 100/50 Mbps average per user (*)

40/10 Gbps 1.6/0,4 Gbps average per user (*)

2012

10/2,5 Gbit/s 400/100 Mbps average per user (*)

2016

XG-PON1

NG–PON2

GPON

Fiber technologies

Copper technologies

t

2010

Performance

Up to 1Gbps for Loop <100m

2012 2016

G.FAST

2015

VDSL2

Up to 50Mbps for Loop < 700 m

Vectoring Up to 100Mbps for Loop < 300 m

On the copper line: more bandwidth but for shorter loops!

… Fiber is needed deep in the access network

E-VDSL Up to 200Mbps for Loop < 300 m

Fiber technologies

(*) Average per user in the hypotesis of splitting factor 1:64 and active HH contemporary factor of 50%

4

An example of TIM effort in Fiber deployment

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Source : 2015 EU Industrial R&D Investment Scoreboard (updated 2016, April)

TIM is going to cover 84% of households by 2018, deploying about 18 millions Km of fiber all over the Country with complementary FTTC and FTTH approach

5

…and Mobile Networks as well…

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84 Mbps

168 Mbps

336+ Mbps

100 Mbps

3 Gbps

1 Gbps

LTE/ LTE-A

150 Mbps

2010-2012 2013-2015 2016-2019

21 Mbps

42 Mbps HSPA+

Feature available

Technology evolution feature

11-23 Mbps

5 Mbps

23 Mbps

46+ Mbps

50 Mbps

500 Mbps

300 Mbps

75 Mbps

DL

UL

DL

UL

Commercial HSPA+

Commercial LTE

HSPA Evolution

DC and LTE evolution

HSPA+ Advanced

LTE Advanced

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… but perhaps it is not crystal clear to all that …

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APPLICATION THROUGHPUT ≠ BIT-RATE

Telco Costs Services & End-User Requirements

THROUGHPUT << BIT-RATE !!!

40-50% of the available

bit rate is used

* Sample measures at my home

…a subjective example…

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… the «bit-rate waste» is everywere… …and it gets worse for higher Bit Rates !

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(*) Ookla SpeedTest data ( Bit Rate) - (4Q13) (#) Akamai connection speed ( Throughput ) - (4Q13)

For growing bit-rate: • the ratio Throughput / BitRate decreases • the “bit rate capacity waste” is more severe

(4Q14) (4Q14)

EU calculated as the average of Italy, UK, Spain, Germany, France, Finland, Denmark, Nederland, Sweden, Romania

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Focus on: IP Transport Performance and QoE

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Since most of Internet traffic is TCP based, in order to «properly design and

manage» IP Networks (no bottlenecks or systematic congestion) 2 parameters that limit

TCP performances have to be carefully optimized:

Network Latency (RTT) and Packet Loss (PLR)

𝑻𝑪𝑷𝒕𝒉𝒓𝒐𝒖𝒈𝒉𝒑𝒖𝒕 <𝑪 × 𝑴𝑺𝑺

𝑹𝑻𝑻 × 𝑷𝑳𝑹

𝑴𝑺𝑺: 𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑆𝑒𝑔𝑚𝑒𝑛𝑡 𝑆𝑖𝑧𝑒

e. g. ≃ 1,5𝐾𝑏𝑦𝑡𝑒𝑠

𝑪: 𝑎 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 typical range: 0,9 − 1,1

𝑹𝑻𝑻: 𝑅𝑜𝑢𝑛𝑑 𝑇𝑟𝑖𝑝 𝑇𝑖𝑚𝑒 between the TCP connection end-points

𝑷𝑳𝑹: Packet Loss on the path between the TCP connection end-points

APPLICATION

Internet Reference Model

TCP

Rif: M.Mathis et Al. , “Macroscopic Behavior of TCP Congestion Avoidance Algorithm, July 1997

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TCP max. Throughput - RTT - Packet Loss

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Rif: M.Mathis et Al. , “Macroscopic Behavior of TCP Congestion Avoidance Algorithm, July 1997

Da

ta ra

te [ M

bp

s ]

MAX TCP Throughput

100

30

High Application Throughput

requires low delay and low

packet loss

When RTT is “high”, the

Throughput is “low”, even if

the “bit rate” is high !

Access Bit Rate

60

10

Mastering QoE – A «layered» vision might help

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IP basic

connectivity Network basic Functions

Value Added

delivery

Net Value and

Quality Functions

Net Neutrality

Regulation

Constraints

Out of the NN

Regulation

Scope

Platforms

Regulation Over The Net

Applications

Telco

Applications

Third Parties

Applications

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Use Case: IP Basic Connectivity

Telecom Italia- all rights reserved Access Node

QoE/Net Value enabling function Networking Node

Network

Value

Functions

Slice

«IP Basic

Connectivity»

Network Slice

Control functions, Real Time Mgmt

(e.g. Mobility/Session Mgmt, BNG

functions, vCPE…)

Control function

CP UP

CP/UP

Operator services, Enterprise, Vertical

Telco Applications Third Parties Applications

E.g: some applications may ask for a simple “IP basic” connectivity

End-to-end functions provided at different logical layers and tailored for specific «asset provisioning» may be seen as a slice.

12

Use Case: Quality Enhanced Delivery

Telecom Italia- all rights reserved Access Node Networking Node

Network

Value

Functions

Operator services, Enterprise/Vertical

Telco Applications

Caching TCP accel

Network Slice

CP/UP

Slice

«Quality Enhanced

Delivery»

QoE/Net Value enabling function

Control function

CP

UP

Third Parties Applications

Quality Enhanced Functions

(e.g. Caching, TCP

accelerator…) in addition to

IP Basic Connectivity

…..other applications (e.g. video services) typically ask for specific requirements better addressed with dedicated QoE platforms ….

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So how to improve QoE? Reduce the RTT and PLR!

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…in order to improve QoE it is not

sufficient to work at the «IP basic

connectivity» level only…

Mobile

Access

Fixed

Access

All-IP Domestic Network

International

Network Core

Metro Regional

UBB access

Network QoE Platforms.

Aggregation

…it takes to work on

Application Transport (layer 4)

i.e. use QoE Platforms

x

14

«Sky» Functions (caching, acceleration) improve QoE

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TCP Acceleration Caching

Both are QoE Enhancement Functions, operating over the IP Network Layer ( no regulation restrictions expected)

Throughput Improvement Throughput Improvement & Network Capacity saving

Suitable for all TCP-based traffic – better for «bulk data flows» (e.g. high def. Video)

Suitable for all TCP-based unencrypted traffic - better for «popular contents»

Suitable for «fixed» and «mobile»

Throughput improvement depends on «where» deployed in the network

Best «in the middle» of E2E path Best «near to EndUsers» (…but depends also on Cache Efficiency…)

Caching TCP Acceleration

15

Throughput Improvement by Cache & Accelerator

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CO

RE

Met

ro

Ag

gre

gat

ion

AC

CE

SS

E

DG

E

Remote Server

End Users

Cache Accelerator

RTTCache

RTTAccelerator

Core Node

Metro Node

Access Node

ITZ GTW RTTTot

EC Cache Efficiency (Hit Ratio);

EA Accelerator Efficiency

Case Study Range

Case Study Range

Case Study Range

One Cache + One Accelerator

Speed up conservative evaluation (related only to RTT reduction)

16

Take away…

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For «properly designed and managed» IP Networks (no bottlenecks or

systematic congestion), performance/QoE is mainly limited by:

Network Latency

Packet Loss

Bandwidth increase and QoS

Functionalities (e.g. CoS, ToS…) are

not sufficient to improve User

Experience…

QoE platforms (e.g. CDN, Cache,

Protocol Accelerator…) are needed

to reach the differentiated QoE

levels required by Applications

17

Grazie! lorenzo.santilli@telecomitalia.it