IP Performance Okt Sigit

7/29/2019 IP Performance Okt Sigit

1/44

1

OVER SATELLITE

BY SIGIT JATIPUTRO, ST MM

SENIOR MANAGER

PT. PASIFIK SATELIT NUSANTARA

INDONESIA

Presented for ASSI Training, 25-27 Oktober 2011


2/44

A enda

2

TCP/IP Performance


3/44

IP Introduction3

To understand Internet Protocol in general


4/44

IP Introduction Best-effort delivery service :

4

IP makes its best effort to deliver segments

between communicating hosts, but it makes noguarantees. Unreliable

Connectionless

Datagram Delivery

ow con ro o ransm ss on on roProtocol):

Timer to be acknowledged Time-out larger than the connections round trip time

Network congestion indicated by TCPsegment loss as indicated by : a time-out or a triple duplicate

acknowled ment


5/44

Continued.. A TCP connection control its transmission rate by limiting its number of

5

Slow start : TCP connection start with a small value of window size (w) TCP connection continue to increase wuntil a segment loss occurs when such loss occurs, the TCP connection reduce wto a safe leveland then

slowing increasing w

Congestion avoidance : when the congestion window is below the threshold, the congestion window

grows exponentially,

linearly whenever there is a time out, the threshold is set to one half of the current

congestion window & the congestion window is then set to one


6/44

TCP and UDP The internet Protocol makes available two transport protocols to applications,

6

,

TCP Services : connection-oriented service : handshaking procedure before TCP connection established

reliable transport service ; the communicating process can rely on TCP to deliver allmessages sent without error and in the proper order

TCP does not provide : no guarantee a minimum transmission rate

no delay guarantee

UDP service :

connectionless : no handshaking be ore the two process start to communicate unreliable data transfer service does not include a congestion control mechanism does not use acknowledgments or retransmission


7/44

Sample Application,

.7

Application Applicat ionLayer Protocol UnderlyingTransport Protocol

Email SMTP TCP

Remote

terminal

access

Telnet TCP

Web HTTP TCP

Remote file

server

NFS UDP or TCP

Streaming

multimedia

Proprietary (e.g..

Real Network)

UDP or TCP

Internet

telephony

Proprietary (e.g..

Vocaltec)

Typically UDP


8/44

Unicast vs Multicast8


9/44

IP Multicast Multicast technology enables data to be simultaneously transmitted to manynetwork users,

9

Permits a network node to transmit one message to one or more nodes in a single operation

The delivery of packets from one (or many) sender to a group of receiver with a singletransmit operation

The internets broadcastin technolo standard. Satellite became the rimar delivernetwork for most Internet multicast traffic. Relieve terrestrial bandwidth bottlenecks

Multicast application :

the upgrade) streaming continuous media (the transfer of the audio, video and text of a live lecture to

a set of distribute lecture participants)

share data a lication whiteboard or teleconferencin a lication that is shared amonmany distributed participants)

Internet web caching, kiosk multimedia ebook, product inventory, etc


10/44

Continued.. Bandwidth saving up to 1/N of the bandwidth for N separate unicast clients

10

Using UDP transport protocol

ass ype a ress . . . . . .

Internet Group Management Protocol (IGMP)

specific multicast group

Multicast routing protocol :

s ance ec or u cas ou ng ro oco

Protocol Independent Multicast (PIM) PIM-Dense Mode

PIM-Sparse Mode

u cas


11/44

IP Multicast Benefit Cost saving in network & server resources

11

Enable value-added of new types of applications

cost

Help alleviate network congestion

Significant bandwidth saving

examp e : it took 6 hours for Toys R Us Inc. to send s/w update (1 Mbytes file) to 250 storelocation before using IP Multicasting

but only took 4 minutes after using IP Multicasting


12/44

A lication La er Data Loss :

12

Reliable data transfer or no data loss application : e-mail, file transfer, web

document transfer & financial application Loss tolerant application : most notably multimedia application such as real-time

audio/video or audio/video

Bandwidth :

Bandwidth-sensitive application : require a given amount of bandwidth

Elastic bandwidth application : can make use of as much or as little bandwidthas happens to be available

m ng : Time-sensitive for real-time application

No time-sensitive for non real-time application


13/44

Continued..13

Application Data Loss Bandwidth Time

Sensitive

File transfer No loss Elastic No

Email No loss Elastic No

Web Doc No loss Elastic No

Realtime audio/video Loss tolerant Audio : few Kbps to 1 Mbps

Video : 10 Kbps to 5 Mbps

Yes : 100 ms

Stored audio/video Loss tolerant Same as interactive audio/video Yes : few sec

Interactive games Loss tolerant Few Kbps to 10 Kbps Yes : 100ms

Financial

applications

required Elastic Yes and no


14/44

Multimedia A lication Delay sensitive and loss tolerant

14

Three classes of multimedia application : streaming stored audio and video

on- eman compresse au io & vi eo i e w ic are store on servers

could be user interactive

one to many streaming of real-time audio & video similar to ordinary broadcast of radio & television, except the transmission take place

over the internet

the application is non-interactive

efficiently done by multicast

real-time interactive audio & video

example : internet phone & video conferencing

IP, the Internets network-layer protocol, provide a best-effort service to all


15/44

Continued.. How should the internet evolve to better support multimedia ?

15

2 extreme arguments :

to add more bandwidth fundamental change should be made to the internet

Quality of service in the internet to individual application session =Integrated Service

reserved resources a router is require to now w at amount o its resources ( u er, in an wi t ) are

already reserved for on-going session

bandwidth reservation protocol (RSVP) : used by a host or router to reserve bandwidthfor their data flow

a session requiring QoS guarantees must first be able to reserved sufficient resources

at each network router (end-to-end) to ensure the QoS requirement is met


16/44

IP Performance Over Satellite16

To understand IP Problem or limitation over satellite

increase IP Performance over satellite (how to improve)


17/44

TCP IP Phenomena17

Long propagation delay:The propagation delay between an earth station and a Geostationary Earth Orbiting(GEO) satellite is around 120-140ms (milliseconds), which means it takes the senderlong time to probe the network capacity and detect the possible loss of segments, andthe expensive satellite bandwidth is wasted.

Large delay-bandwidth product:The GEO satellite link is a typical case of the Long Fat Pipe (LFP), which features alarge delay bandwidth product.

Corruption loss during transmission:-

(SNR) and consequently a high Bit Error Rate (BER). The errors loss will cause the TCPsenders to reduce their transmission rates unnecessarily.


18/44

IP Throu h ut IP throughput (how fast the most application will move data over other network) will affect by :

18

s o avo pac e sem -permanen c rcu ar

will decrement every pass 1 loop router

will decrease by at least 1 every 1 second (theoretical 4.26 minute, but practical 2 minute)

IP Fragmentation

MTU (maximum transfer unit), max 1500

MTU Discovery to avoid double IP fragment ID

Some application have sensitive MTU value

Delay-Bandwidth Product

Multiple by delay RTT and bandwidth path

,

PAWS, comparing TCP sequence number with timestamp

TCP Transmission Window

The purposes to allow the receiving side to control how much data being sent to it at any given time

Max value 64 KB

Receiver send negotiation scheme to sender


19/44

Continued..19

There 3 factor mechanism of TCP/IP that can impact on satellitenetwork (with long delay path) :

Slow start mechanism TCP Spoofing

Cascading TCP (TCP Splitting)

Congestion avoidance mechanism To improve the SACK (selective-acknowledgement) mechanism must be enable

Error rate for satellite paths Will impact tcp/ip start again to trigger slow start mechanism

The TCP IP must be i nore the error rate or the link must be ver minimal BER(In the high speed data around 1 error in 10^12 bits of data)


20/44

TCP/IP Impact of

, ,20

From the test result :

Higher delay path will give more slow start time

Higher bandwidth rate will give more slow start time Higher slow start time will give TCP/IP more slowly or cant fulfill the

bandwidth link capacity


21/44

TCP/IP Impact of

, ,

Two performance measured :

21

ec ve roug pu or a arge e rans er

Response time for a Web page retrieval

Three reference cases :

Terrestrial

Hybrid (satellite/terrestrial)

2 way satellite circuit

Assume : error free and no congestion channel

Effective throughput : determined by dividing the number of bits in the file by the time it taketo transmit the file

Response time : defined as the time it takes to transmit a file once the file transfer is initiated

n ow s ze : a parameter use or ow congest on contro n e trans er


22/44

Continued..22


23/44

Continued23

Link Bandwidth = 2048 Kb s

Link Bandwidth = 256 Kbps


24/44

TCP/IP Impact of

, ,24


25/44

TCP/IP Impact of

, ,25


26/44

How to im rove

26

TCP Splitting

Caching

us ng ontent to t e ge

Reactive Multicast Feeds


27/44

TCP EnhancementTCP RFC Late- Large Impairments & Asym-

27

ncy BDP Disconnections metry

Large IW 2414, 2581 X

DACKs X

Byte Counting 2414 X X

TCP NewReno 2582 X X X

TCP SACK 2018, 2883 X X X

TCP Vegas X X X

Window Scaling 1323 X X

T/TCP 1644 X

PMTU Discovery 1191 X

ECN 2481 X X

Header 2507 X

Compression


28/44

TCP S littin28

Comparison etween 1 TCP session wit mu tip e TCP session (sp itting met o )


29/44

TCP S littin continuedWithout Enhancement With Protocol Gateway

29

Protocol atewa s littin im rove throu h ut for carriers with TCP IP

traffic on satellite links up to a delay of 700 ms TCP/IP throughput is not affected as long as link BER is better than 1 x 10-7

Study the impact of BERs < 10-7

Review recommendation ITU-R S.521-4 in view of satellite IP


30/44

TCP S oofin30

TCP Spoofing Gateway router give pseudo ACK to sender, so it will give impact

faster link illusion to sender

Gateway router will buffer this TCP packet and responsible toretransmit if receiver side need that packet

Gateway router will removes ACK from receiver so there is noup ca e o sen er


31/44

Cachin31

A cache is a local device that stores and refreshes recentlyrequested objects

The cache improves performance because it serves thecustomers request locally, instead of taking time (and


32/44

Pushin Content to the Ed e32

provider to distribute web documents selected by content provider. There isa mechanism for letting ISPs know where the closest edge site is located.This insures good response time for the transaction, and also reduces


33/44

Reactive Multicast Satellite Feed Improves

33


34/44

A lication34

To understand some of ip-based satellite networks

To understand convergence networks


35/44

ITU Working Groups

emen s Broadband Satellite Multimedia (BSM)

35

Main ocus or IP Broadband over Satellite

Satellite Component of UMTS/IMT-2000 (S-UMTS)

Develo in a S UMTS air interface based on the 3GPP UMTS air interface. IMT-2000_candidate).

Collaboration between ESA (Europe) and TTC (Korea)

Developing a GMPRS MES air interface based on the GSM/GPRS packet-mode airinterface.

GMR-1 is implemented in Thuraya Hughes Co.

- s mp emen e n e oc ee ar n o.

Satellite Air Interface (SAI)

Re enerative Satellite Mesh A RSM-A , Im lemented b Hu hes

Maritime Earth Station (MAR)


36/44

Broadband Satellite Multimedia (BSM)

36


37/44

Multimedia Networks (concept)

-37

Satellitenetwork

for interactivity

and symmetrictraffic

orpermanentcontent

update andre res ng

an setwith build-incachememory


38/44

IP QoS for SatelliteISP 1ISP 1

38

Service Link ProviderService Link Provider

erv oma nerv oma n

ISP 2ISP 2

IP/DVBIP/DVB

COPSCOPSSLA traderSLA trader IOTPIOTP

SLA traderSLA trader

uplinkuplink

IOTPIOTP

You have 2 Mbps Gold (EF) for me ?You have 2 Mbps Gold (EF) for me ?

Yes, at 300Yes, at 300/hour/hour

Terrestrial returnTerrestrial returnImplement of QOS :

- serv on orwar n , nc u ng ec an mu p e a eway

-Dynamic SLA trading between ISP and Space Link Provider

-Throttling or Fair Access Policy


39/44

Higher System Capacity

HRBHRB

39

MNL

KUL

BKK

HAN

SGN

TPE

NAY

CTU

CAN

SHA

SHE

SELITM

-3

-3

-3

-3-3

-3

-3

-3

-3

-3

-3 -3

-3

-3

-3

-3

-3

-3

-3

-3

-3 -3

MNL

KUL

BKK

HAN

SGN

TPE

NAY

CTU

CAN

SHA

SHE

SELITM

-3

-3

-3

-3-3

-3

-3

-3

-3

-3

-3 -3

-3

-3

-3

-3

-3

-3

-3

-3

-3 -3

-3

-3

-3

20

20

0.00

5.00

Degrees

BNE

CBRPER

HLPPOM

-3

-3 BNE

CBRPER

HLPPOM

-3

-3-3

-3

-3

-3

-5.00

Theta*sin(phi)i

20

Multi-Beam Coverage

More than ten times capacity

Higher effective system bandwidth

bandwidthallocatedcellsofnumber

Single Wide Area Coverage Beam

Effective bandwidth =

Example: 50-beam system using dual polarization

Effective bandwidth = = 12.5 GHz

factorreuseFrequency

4

MHz)(5002)(50

Equivalent number of 36 MHz transponders 12.5 GHz/40 MHz = 310


40/44

Mobile or Marine

40

Proxy connection TCP Optimal flow (removes slow start, splitting)

TCP Windows Spoo ing


41/44

VOIP over Satellite

Latency

41

One-way propagation delay (250 ms)

Jitter The effect of network delay on packets arriving at the receiver

Pac et Loss

Depend on BER (bit error ratio) will impact on voice quality

QoS and Traffic Prioritization

or pr or za on

Compression Technology

Codec : G711, G723, G729, etc

Depend on codec : 5.6, 10 12, 16, 24, 64, etc kbps

VOIP Access Method Protocol

, , , ,


42/44

GSM BTS over Sat-IP42

Isolated

Cells Management

Gateway

Management

Gateway

BSC

Terminal

Backbone

MSC

Platform

Theimagecannotbedisplayed.Yourcomputer may nothaveenough memory toopen theimage,or theimagemay havebeen corrupted.Restartyour computer,andthen open thefileagain.Ifthered x stillappears,you may haveto del etetheimageand then insertitagain.

Backbone

a orm

RASHUB

BTS

Isolated

Cell Cluster Terminal

EdgeEdge

MSC BSC

Implemented in USO Desa Berdering in 2010 Voice, SMS and Pico-Cell 1 TRX

- -

IP Hi h B d id h


43/44

IP Higher Bandwidth

v Due to internet penetration, social networking, mobile ISP

43

and number of application based on internet, then trend of

IP bandwidth is significant increase during last a few years

ISP need Asymmetric bandwidths for internet GE from 10 Mbps until 120 Mbps

Cellular Backhaul (BTS & 3G Node-B) increase bandwidth FE or OC-1 from 2 Mbps until 45 Mbps (symmetric)

OC-3 until 155 Mbps (symmetric)

NASA Development ACTS OC-12 until 622 Mbps over satellite (symmetric)

FlatSat internet communication between ground and spacecraft


44/44

44

TERIMA KA IH

,

[email protected]

Documents

IP Performance Okt Sigit