understanding and enhancing the scalability of ims-based ... · understanding and enhancing the...

Understanding and Enhancing the Understanding and Enhancing the Scalability of IMSScalability of IMS--based based

Infrastructures and ServicesInfrastructures and Services

Luca Foschini

Oct. 20th 2009, P2MNet, Zurich

Research FellowDEIS, University of Bologna, ITALY

[email protected]

Zurich — 20.10.2009 P2MNet 2/54

AgendaAgenda

Service delivery in 4G converged Internet

IP Multimedia Subsystem – IMS – scalabilityissues

IHMAS middleware for scalability of IMS-based infrastructure and services

IHMAS presence service scalability use case– Infrastructure scalability

– Intra-/Inter-domain service scalability

– Implementation details and experimental evaluation

Concluding remarks and open research directions

Zurich — 20.10.2009 P2MNet 3/54

Ever-increasing demand and diffusion of mobile multimedia services during the last two decades, driven by:

– New powerful devices and wireless technologies/infrastructures

– New (mobile) services

4G converged world4G converged world

Voice (VoIP)

Audio/Video Conference

Video on Demand (VoD)

Chat and messagging

And many more…

?...

- Push To Talk (PTT)- PTT over Cellular (PoC)- IPTV - Video sharing- ...

Zurich — 20.10.2009 P2MNet 4/54

4G converged 4G converged service delivery scenarioservice delivery scenario

Mobile multimedia services offered

by network operators(e.g., VoIP, IPTV, …)

Mobile multimedia services offered by third party (Internet)

service providers(e.g., weather forecast, news, …)

Operators’ core IP networks providing basic services:QoS-enabled data transport, mobility, AAA, …

Service delivery platform: an all-IP overlay to

facilitate service access and integration (e.g. IMS)

IEEE 802.11(WiFi)

Bluetooth

Cellular 3G and WiMAX

Highly differentiated (wireless) access networks

Zurich — 20.10.2009 P2MNet 5/54

IP-basednetwork

Hotspot Wi-Fi Hotspot Wi-Fi

3G cellular

4G service & network management:4G service & network management:a proxya proxy--based approachbased approach

IMSIP Multimedia Subsystembased on SIP(Session Initiation Protocol)

New protocols and active proxy-based infrastructures for session management

Zurich — 20.10.2009 P2MNet 6/54

New service scenarios in 4G:New service scenarios in 4G:handoff management of mobile multimediahandoff management of mobile multimedia

WLAN

Bluetooth GPRS

IP-basednetwork

IMS-based components

Zurich — 20.10.2009 P2MNet 7/54

PSP

WatchersIMS-based

Presence ServicePresentities

Presence service (PS) permits users and hw/sw components, called presentities (Pi ), to convey their ability and willingness to communicate with subscribed watchers (Wj )

PUBLISH IMSP

New support services in 4G:New support services in 4G:presence servicepresence service

P1

P2

PNWN

W2

W1

SUBSCRIBE(to P2@domainP)

SUBSCRIBE

SUBSCRIBE

(to P2@domainP)

(to P2@domainP)

IMSW NOTIFY

NOTIFY

domainP domainWNOTIFY

Zurich — 20.10.2009 P2MNet 8/54

Need for a better understanding of IMS scalability shortcomings and load-balancing support both at infrastructure and service levels

New services VoIP+PS(call-status notification)

Higher signaling traffic (message dimension + frequency)Richer services, such as VoIP+PS(message multiplying effect)Many traversed signaling entities (proxies-based architecture…)Plus, specific SIP protocol issues (message verbosity and ACKs)

Scalability issues at a glanceScalability issues at a glance

High mobility & context changes

Zurich — 20.10.2009 P2MNet 9/54

Some background:Some background:SIP SIP –– SessionSession InitiationInitiation ProtocolProtocol

SIP defines a signaling framework and related protocols and messages to setup any kind of session(work at the Open Systems Interconnection – OSI –session layer)

– SIP is very open and general purpose ☺– SIP includes several core facilities for mobility management,

session initiation, termination, and transfer, …– SIP does not include some basic services

(e.g., AAA, resource booking, …)

SIP is not a data/media transmission protocolOther specific protocols for that: Real-time Transport Protocol (RTP), RTP Control Protocol (RTCP), Real Time Streaming (RTSP),…

SIP usage examples– Setting up and tearing down VoIP voice calls– Instance messaging and presence service: SIP for Instant

Messaging and Presence Leveraging Extensions – SIMPLE– Session transfer and call re-direction

Zurich — 20.10.2009 P2MNet 10/54

SIP in a nutshellSIP in a nutshell

SIP core signaling– HTTP-like text-based protocol and email-like SIP identifiers (addresses)

– Client/server protocol (request/response protocol)– Standardized session control messages

INVITE, REGISTER, OK, ACK, BYE, …

SIP proxy-based framework and main entities– User agents: end points, can act as both user agent client and as

user agent serverUser Agent Client: create new SIP requestsUser Agent Server: generate responses to SIP requests

– Dialog: peer to peer relationship between two user agents, established by specific methods

– Proxy servers: application level routers– Redirect servers: redirect clients to alternate servers– Registrars: keep tracks of users

Zurich — 20.10.2009 P2MNet 11/54

SIP SIP VoIPVoIP call initiation example:call initiation example:INVITE dialogINVITE dialog

CALLER PROXY A CALLEEPROXY B

(1) INVITE

(4) ACK

(6) 200 OK

Media session (e.g. RTP-based, NOT SIP)

(2) RINGING

(3) 200 OK

(5) BYE

INVITE sip:[email protected] SIP/2.0

Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bK776asdhds

Max-Forwards: 70

To: Bob <sip:[email protected]>

From: Alice <sip:[email protected]>;tag=1928301774

Call-ID: [email protected]

CSeq: 314159 INVITE

Contact: <sip:[email protected]>

Content-Type: application/sdp

Content-Length: 142

… SDP description …

Start line:• request line (in requests)• status line (in responses)

Header: with a number of header fields

Message body (optional): for example, an SDP description to negotiate audio/video codecs/formats

SIP is very verbose and

acknowledged; in addition,

SIP parsing is CPU-intensive

Zurich — 20.10.2009 P2MNet 12/54

DNS1

Some background:Some background:IMS IMS –– IP Multimedia SubsystemIP Multimedia Subsystem

Visited network 1

P-CSCF

Home Network 1 Home Network 2

Visited network 2

P-CSCF

AS AS

S-CSCF S-CSCF

I-CSCF I-CSCFHSS HSS

MobileNode(MN)

Corresp. Node(CN)

Proxy-based architectureworking at OSI session layer

Common set of functions to easemultimedia service deployment

in highly heterogeneouswireless computing environments

SIP (+ Diameter)

DATA FLOW

Signaling Functions

Application Servers (ASs)Signaling Functions/Entities for

IMS Signaling Extension/Integration

Authentication Functions

DNS2

Zurich — 20.10.2009 P2MNet 13/54

IMS functional entities:IMS functional entities:DNS and HSSDNS and HSS

Domain Name System (DNS):Standard Internet naming serviceEmployed by IMS to resolve the IP addresses of CSCFs and ASs

can be used for load balancing ☺(but… only with limited DNS-query frequency)

Home Subscriber Server (HSS):SIP requests forwarding in the appropriate direction(terminals or IMS network)

Storage of all user-related subscription data, such as authentication data and profiles for clients (by using standard Data Base Management System – DBMS)

A network may contain one or several– Subscriber Location Function (SLF) to map users to specific HSS

Zurich — 20.10.2009 P2MNet 14/54

IMS functional entities:IMS functional entities:ProxyProxy--CSCFCSCF

Proxy-Call Session Control Function (P-CSCF):First contact point in the IMS network in either visited domain or home domain

Outbound / In-bound SIP proxy(all requests from/to IMS terminals go through it)

Main P-CSCF functionsSIP requests forwarding in the appropriate direction(terminals or IMS network)

Several other functions:– Security

– Generation of charging information

– Compression and decompression of messages

Zurich — 20.10.2009 P2MNet 15/54

IMS functional entities:IMS functional entities:InterrogatingInterrogating--CSCFCSCF

Interrogating-Call Session Control Function (I-CSCF):SIP proxy at the edge of the administrative home domain

– There may be several in the same network for scalability reasons– Listed in the domain name server (DNS-based scalability)

SIP redirect stateless server

Main I-CSCF functionsInteraction with HSS to determine the S-CSCF associated with the client (Diameter protocol)

Redirection and routing of incoming SIP requests to S-CSCF

can be used to dynamically select less-loaded S-CSCFs (e.g. through DNS) ☺

Zurich — 20.10.2009 P2MNet 16/54

IMS functional entities:IMS functional entities:ServingServing--CSCFCSCF

Serving-Call Session Control Function (S-CSCF):Always located in home domainSIP proxy + SIP registrar with possibility of performing session control

Main S-CSCF functionsBinding between IP address (terminal location) and user SIP addressInteraction with application servers for value added service purposeTranslation services (Telephone number / Sip URIs)Message routing (by using so-called IMS filtering criteria)

can be used to statically divide incoming load according to user identity/profile ☺

Zurich — 20.10.2009 P2MNet 17/54

IMS functional entities:IMS functional entities:ASAS

Application Server (AS):Host services and execute services

Communicates using SIP: very costly!!– Each interposed AS generates 2 msgs (processed+ACK)

– Complex coordination for stateful and distributed ASs

Several AS types with different functionsSIP AS: signaling specific architecture (services can work only in SIP environment)

Other types: Open Service Architecture – Service Capability Server (OSA/SCS), IP Multimedia Service Switching Function (IM-SSF), …

Zurich — 20.10.2009 P2MNet 18/54

IMS RevisitedIMS Revisited

Visited network 1

P-CSCF

Home Network 1 Home Network 2

Visited network 2

P-CSCF

AS AS

S-CSCF S-CSCF

I-CSCF I-CSCFHSS HSS

MobileNode(MN)

Corresp. Node(CN)

DATA FLOW

DNS1 DNS2

1.

4.

5.

6.

7.

8.2.MN “in call”

3.

I-CSCF requiredon registration

load-balancing

Many components high overhead

Adequate infrastructure load-balancing

support, BUT no monitoring support

AS load-balancing support is insufficient

Zurich — 20.10.2009 P2MNet 19/54

Single host (local) optimizations w/out (or with minimal) coordination:– Selective message dropping– SIP message compression and

incremental parsing techniques– Stateful vs Stateless SIP proxies

Intra-domain (distributed) load-balancing:– Infrastructure-level monitoring and

dynamic load-balancing operations– Service-level AS coordination protocols

(also ad-hoc and NON-IMS-compliant optimized protocols!!)

Inter-domain protocol optimizations:– Limit traffic among different domains– Service-level message processing at IMS

domain borders (BUT, IMS compliant)

IMS scalability:IMS scalability:(partial) solutions(partial) solutions

Widely diffused and standardized

Zurich — 20.10.2009 P2MNet 20/54

One unique framework able to provide an effective solution to all the different IMS load-balancing issues is still lacking

One solution that integrates local, intra-domain, and inter-domain load balancing is still missing

One significantly tested solution:most papers in the IMS literature are insufficiently validated and do not include extensive experimental results collected in real-world distributed testbeds

IMS scalability:IMS scalability:open issuesopen issues

Zurich — 20.10.2009 P2MNet 21/54

IHMAS: IHMAS: emerging design guidelines emerging design guidelines for IMS scalabilityfor IMS scalability

IMS-compliant Handoff Management Application Server Active session signaling (proxy-based approach)

Intra-domain (IMS) infrastructure load balancing– Collects service-aware distributed monitor alarms– Decides and executes needed load-balancing actions

(dynamic addition/removal of CSCF components)

Intra-domain service load balancing – Adopts a data-centric session management approach to

share service state into AS pools– Exploits specific service knowledge (service awarereness)

to divide intra-domain load into partitions

Inter-domain transmission optimizations– Controls and reduces inter-domain traffic– Realizes service-aware message aggregation and batching

techniques based on distributed AS federation models

Zurich — 20.10.2009 P2MNet 22/54

IMS

DOMAIN P DOMAIN W

PS

IMS

PS

WN

W2

W1P1

P2

PN

SUBSCRIBE(to P2@domainP)

SUBSCRIBE

SUBSCRIBE

SUBSCRIBE

(to P2@domainP)

(to P2@domainP)

Inter-domain PS scenarioP: Presentity PS: Presence Server

W: Watcher

IHMAS PS scalability use caseIHMAS PS scalability use case

Zurich — 20.10.2009 P2MNet 23/54

IMS

DOMAIN P DOMAIN W

PS

IMS

PS

WN

W2

W1P1

P2

PN

Inter-domain PS scenario

PUBLISH(e.g.:”I’m online”)

NOTIFYNOTIFY

NOTIFY

NOTIFY

IMS-based components

PS is very prone to load-balancing issues!!

IHMAS PS scalability use caseIHMAS PS scalability use case

Zurich — 20.10.2009 P2MNet 24/54

IHMAS intra-domain infrastructure load-balancing– monitors distributed infrastructure and service

components (I-/P-/S-CSCFs, HSS, PS, any AS, …)

load monitoring actions tailored for the specific service (service-aware approach)

– executes application-level specific component load-balancing actions

dynamic de-/activation of distributed components and DNS (de-)registration actions

– integrates seamlessly with existing infrastructuresfull compliancy with IMS standard

P. Bellavista, A. Corradi, L. Foschini, “Enhancing the Scalability of IMS-based Presence Service for LBS Applications”, IEEE COMPSAC, 2009P. Bellavista, A. Corradi, L. Foschini, “IMS-compliant Management of Vertical Handoffs for Mobile Multimedia Session Continuity”, accepted for IEEE Communications Magazine

IHMAS intraIHMAS intra--domain PS scalability:domain PS scalability:infrastructure loadinfrastructure load--balancingbalancing

Zurich — 20.10.2009 P2MNet 25/54

Decision Maker –DM: takes load balancing and partitioning decisions

Load-Balancing Executor – LBE: enforces them

Proactive Monitoring Stub – PMSx: monitor system/ component behavior and generate overload alerts towards DM

IMS components: I-/P-/S-CSCF, HSS, PS, DNS

IHMAS intraIHMAS intra--domain PS scalability:domain PS scalability:infrastructure loadinfrastructure load--balancingbalancing

PMS: Proactive Monitoring Stub DM: Decision Maker LBE: Load-Balancing Executor

S-CSCF1

S-CSCF PMSS-CSCF

S-CSCF2

PMSS-CSCF

S-CSCFs

PS1

PS PMSPS

PSs

DB

W1 P2

P1

W2

DNS

P-CSCF1

P-CSCF PMSP-CSCF

P-CSCF1

P-CSCF PMSP-CSCF

I-CSCF

I-CSCF PMSI-CSCF

HSS

HSS PMSHSS

PS2

PMSPS

Load Balancer

IHMAS Load Balancer

DMLBE

SIP Diameter SQL SSH or UDP

Load Balancer (LB)

IHMAS Load Balancer

DMLBE

Zurich — 20.10.2009 P2MNet 26/54

Open IMS Core

IMS Bench SIPp

• IMS infrastructure

• Presence Server

• SIP traffic generation

OpenSER(now OpenSIPS and Kamailio)

Implementation hintsImplementation hints

• Deployment re-configuration Diskless Remote Boot Linux (DRBL)

Zurich — 20.10.2009 P2MNet 27/54

IMS (PS) traffic emulationIMS (PS) traffic emulation

IMS Bench SIPpIMS traffic generator that conforms to ETSI TS 186 008 IMS/NGN Performance Benchmark specificationIMS Bench SIPp permits to define benchmark configuration scenarios by composing different IMS session phases (e.g., registration, subscription, …)

Zurich — 20.10.2009 P2MNet 28/54

PS traffic benchmarkPS traffic benchmark

Three main phases (in each experiment)

1. IMS clients registration

2. Watcher subscriptions to obtain different watcher-per-presentity (w/p) ratios

3. IMS infrastructure and system stressThis phase is a mix of:

10% subscriptions, 5% registrations, 5% de-registrations, 80% publications (Presentities)

configured with various incremental steps

Zurich — 20.10.2009 P2MNet 29/54

S-CSCF

P-CSCF

IMS Bench Manager

SIPp client

IMS PS traffic

configuration andresult gathering

PresenceServer

(OpenSIPS)

S-CSCF

IMS PStraffic

SIPp client

open-ims.test

IHMAS LB

Open IMS Core

P-CSCF

32 Linux Boxes2CPU 1,8 GHz2048MB di RAM

Experimental testbedExperimental testbed

I-CSCF

S-CSCF S-CSCF

PMS PMS PMS PMS PMS

PMS PMS PMS PMS PMS

DMLBE

Intra-domainDNS

Inter-domainDNS

Zurich — 20.10.2009 P2MNet 30/54

Experimental results:Experimental results:SS--CSCF scalabilityCSCF scalability

Scalability threshold of one S-CSCF component, obtained with: 1 PS, 1 I-CSCF, 1 HSS (not shown), and 3 P-CSCFs

msec

CP

U %

0

20

40

60

80

100

120

140

160

180

200

220

0 60000 120000 180000 240000 300000 360000 420000 480000

S-CSCF PS P-CSCF1 P-CSCF2 P-CSCF3

5 cps 10 cps 15 cps 20 cps 25 cps 30 cps 35 cps 40 cps 45 cps 50 cps 55 cps 60 cps 65 cps 70 cps

Zurich — 20.10.2009 P2MNet 31/54

Experimental results:Experimental results:dynamic Sdynamic S--CSCFsCSCFs loadload--balancingbalancing

0

20

40

60

80

100

120

140

160

180

200

220

0 60000 120000 180000 240000 300000 360000 420000 480000

S-CSCF1 S-CSCF2

5 cps 10 cps 15 cps 20 cps 25 cps 30 cps 35 cps 40 cps 45 cps 50 cps 55 cps 60 cps 65 cps 70 cps

msec

CP

U %

Triggered by the combination of a NOTIFY alarms

Filtering and prediction techniques permits to effectively smooth sporadic peaks

DM activates S-CSCF2

PMSPS alarmPMSS-CSCF1 alarm

Zurich — 20.10.2009 P2MNet 32/54

IHMAS intra-domain service load-balancing– extends IMS PS to support multiple AS service state

storages and fast exchange of (and access to) shared session state among ASs

novel PS intra-domain module to enable data distribution overlays and caching techniques within AS partition

– exploits existing standards for data distributiondata distribution is fully compliant with Data

Distribution Service (DDS), an Object Management Group (OMG) standard

– divides intra-domain service workload by applying a divide-and-conquer principle (for big domains)

IMS routing based on HSS and IMS filter criteriaP. Bellavista, A. Corradi, L. Foschini, “Understanding and Enhancing the Scalability of IMS-based Services for Wireless Local Networks”, IEEE WLN, 2009

IHMAS intraIHMAS intra--domain PS scalability:domain PS scalability:service load balancingservice load balancing

Zurich — 20.10.2009 P2MNet 33/54

DDS

IHMAS intraIHMAS intra--domain PS scalability:domain PS scalability:session datasession data--centric managementcentric management

IMS

IMS

• Service state (both subscriptions and publications) stored locally at PS DB

• PUBLISH write-through (using DDS)

Zurich — 20.10.2009 P2MNet 34/54

Message routing

Statistical load partition based on a hash function evaluated on presentity identifiers exploits HSS + IMS filtering criteria

IHMAS intraIHMAS intra--domain PS scalability:domain PS scalability:static balancing among PS poolsstatic balancing among PS pools

Zurich — 20.10.2009 P2MNet 35/54

IHMAS inter-domain service optimizations– extends IMS PS to support message aggregation/batching

(diminishes the number of inter-domain NOTIFY transmissions)

novel PS inter-domain optimization module for NOTIFY message parsing and inter-domain routing

– supports mobile clients and service differentiation (gold, silver, copper, …)

Gold: instant presence info delivery high costSilver: slightly delayed presence info delivery medium costCopper: very delayed presence info delivery low cost

– integrates seamlessly with existing infrastructuresfull compliance with IMS standard

P. Bellavista, A. Corradi, L. Foschini, “IMS-based Presence Service with Enhanced Scalability and Guaranteed QoS for Inter-Domain Enterprise Mobility”, IEEE Wireless Communications Magazine, vol. 16, no.3, Jun. 2009

IHMAS interIHMAS inter--domain PS scalability:domain PS scalability:transmission optimizationstransmission optimizations

Zurich — 20.10.2009 P2MNet 36/54

Common NOTIFYCommon NOTIFY

IMS

PS

IMS

PS

WN

SUBSCRIBE

SUBSCRIBE

SUBSCRIBE

(to P2@domainP)

W2

W1

(to P2@domainP)

(to P2@domainP)SUBSCRIBE

P2

“Several watchers subscribed to one presentity”

Zurich — 20.10.2009 P2MNet 37/54

IMS

PS

IMS

PS

WN

NOTIFY

NOTIFY

NOTIFY

W2

W1

P2

PUBLISH

NOTIFY +

AggregatesNOTIFY messages

at Presentity’sdomain

1 only inter-domain NOTIFYmessage

NOTIFY messagescreation at

Watchers’s domain

Watchers’list

Common NOTIFYCommon NOTIFY

Zurich — 20.10.2009 P2MNet 38/54

IMS

PS

IMS

PS SUBSCRIBE(to P1@domainP,

P2@domainP,PN@domainP)

W2

SUBSCRIBE

P2

PN

P1

Batched NOTIFYBatched NOTIFY

“One single watcher subscribed for multiple presentities”

Zurich — 20.10.2009 P2MNet 39/54


Time-based (periodic) NOTIFY message batching

IMS

PS

IMS

PSW2

P2

PN

P1

PUBLISH

PUBLISH

PUBLISH

NOTIFY

NOTIFY

NOTIFY

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IMS

PS

IMS

PSW2

P2

PN

P1

PUBLISH

PUBLISH

PUBLISH

NOTIFY

NOTIFY

NOTIFY

NOTIFY

only 1 inter-domainNOTIFY message

NOTIFY

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WA.4 WA.1 P-/S-CSCFA IOMA + PSAWA.3 I-/S-CSCFB IOMB + PSB PB.1 PB.4

DomainA DomainB

(1) SUBSCRIBE (2) SUBSCRIBE (3) SUBSCRIBE (4) SUBSCRIBE

(5) 200 OK(6) 200 OK(7) 200 OK(8) 200 OK(9) PUBLISH

(10) OK

SUBSCRIBEfrom other watchers

(11’) Common NOTIFY(one per presentity)

PB.4

PUBLISHfrom other presentities

(11) NOTIFYGo

ldC

lien

ts

(13’) NOTIFY msgs

(12) NOTIFY

(14’) NOTIFY

(13) OK (14) OK

(12’) OK

(15’) OK msgs (16’) OK

(11’’) Batched NOTIFY(one per watcher)

(13’’) aggregated NOTIFY(14’’) NOTIFY

(12’’) OK

(15’’) OK msgs (16’’) OK

Silv

erC

lient

sC

oppe

rC

lient

s

PrioritizedNOTIFY schedule

Watchers Authorization andNOTIFY construction

Watcher Authorization, NOTIFY aggregation, NOTIFY construction

WA.4WA.4 WA.1WA.1 P-/S-CSCFAP-/S-CSCFA IOMA + PSAIOMA + PSAWA.3WA.3 I-/S-CSCFBI-/S-CSCFB IOMB + PSBIOMB + PSB PB.1PB.1 PB.4PB.4

DomainA DomainB

(1) SUBSCRIBE (2) SUBSCRIBE (3) SUBSCRIBE (4) SUBSCRIBE

(5) 200 OK(5) 200 OK(6) 200 OK(6) 200 OK(7) 200 OK(7) 200 OK(8) 200 OK(8) 200 OK(9) PUBLISH(9) PUBLISH

(10) OK(10) OK

SUBSCRIBEfrom other watchers

(11’) Common NOTIFY(one per presentity)

PB.4PB.4

PUBLISHfrom other presentities

(11) NOTIFYGo

ldC

lien

ts

(13’) NOTIFY msgs

(12) NOTIFY

(14’) NOTIFY

(13) OK(13) OK (14) OK(14) OK

(12’) OK(12’) OK

(15’) OK msgs(15’) OK msgs (16’) OK(16’) OK

(11’’) Batched NOTIFY(one per watcher)

(13’’) aggregated NOTIFY(14’’) NOTIFY

(12’’) OK(12’’) OK

(15’’) OK msgs(15’’) OK msgs (16’’) OK(16’’) OK

Silv

erC

lient

sC

oppe

rC

lient

s

PrioritizedNOTIFY schedule

Watchers Authorization andNOTIFY construction

Watcher Authorization, NOTIFY aggregation, NOTIFY construction

IHMAS interIHMAS inter--domain PS scalability:domain PS scalability:PS protocol enhancementsPS protocol enhancements

Experimental results: CPU load at border CSCF components

Zurich — 20.10.2009 P2MNet 42/54

0

5

10

15

20

25

8

20 33 46 58 71 84 96

109

122

135

147

160

173

186

198

211

224

237

250

263

276

289

302

315

328

341

354

10 CPS5 CPS 15 CPS 20 CPS 25 CPS 35 CPS 45 CPS 55 CPS 65 CPS 70 CPS 80 CPS 90 CPS

0

5

10

15

20

25

8

20 33 46 58 71 84 96

109

122

135

147

160

173

186

198

211

224

237

250

263

276

289

302

315

328

341

354

10 CPS5 CPS 15 CPS 20 CPS 25 CPS 35 CPS 45 CPS 55 CPS 65 CPS 70 CPS 80 CPS 90 CPS

0

25

50

75

100

125

150

175

200

225

8 20 33 46 58 71 84 96 109

122

135

147

160

173

186

198

211

224

237

250

263

276

289

302

315

328

341

354

15 CPS 25 CPS 45 CPS 65 CPS 70 CPS5 CPS 90 CPS80 CPS10 CPS 20 CPS 35 CPS 55 CPS

6.6 w/p 8.6 w/p 10.9 w/p 14.6 w/p

sec

CP

U %

ME

MO

RY

%

sec

Experimental results:Experimental results:w/out IHMAS optimizationsw/out IHMAS optimizations

CPS: Calls Per Secondw/p: mean number watcher subscriptions for each presentity

Zurich — 20.10.2009 P2MNet 43/54

0

10

20

30

40

50

60

70

80

90

8

21 34 46 59 72 84 97 110

122

135

148

160

173

186

198

211

224

237

249

262

275

287

300

313

325

338

351


0

10

20

30

40

50

60

70

80

90

8

21 34 46 59 72 84 97 110

122

135

148

160

173

186

198

211

224

237

249

262

275

287

300

313

325

338

351


0

2

4

6

8

10

12

14

8 21 34 46 59 72 84 97 110

122

135

148

160

173

186

198

211

224

237

249

262

275

287

300

313

325

338

351


Experimental results:Experimental results:with IHMAS common NOTIFYwith IHMAS common NOTIFY

6.6 w/p 8.6 w/p 10.9 w/p 14.6 w/p

sec

CP

U %

ME

MO

RY

%

sec


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0

10

20

30

40

50

60

70

6

18 31 44 56 69 82 95 107

120

133

145

158

171

183

196

209

222

234

247

260

273

285

298

311

323

336

349

15 CPS 25 CPS 45 CPS 65 CPS 70 CPS5 CPS 80 CPS10 CPS 20 CPS 35 CPS 55 CPS 90 CPS

0

10

20

30

40

50

60

70

6

18 31 44 56 69 82 95 107

120

133

145

158

171

183

196

209

222

234

247

260

273

285

298

311

323

336

349


0

1

2

3

4

5

6

7

8

6

18 31 44 56 69 82 95

107

120

133

145

158

171

183

196

209

222

234

247

260

273

285

298

311

323

336

349


0

1

2

3

4

5

6

7

8

6

18 31 44 56 69 82 95

107

120

133

145

158

171

183

196

209

222

234

247

260

273

285

298

311

323

336

349


Experimental results:Experimental results:with IHMAS batched NOTIFYwith IHMAS batched NOTIFY

6.6 w/p 8.6 w/p 10.9 w/p 14.6 w/p

sec

CP

U %

ME

MO

RY

%

sec


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Experimental results:Experimental results:number of internumber of inter--domain domain NOTIFYsNOTIFYs

1

10

100

1000

10000

100000

1000000

6.6 8.6 10.9 14.6 w/p

# N

OT

IFY

me

ss

ag

es

w/o PS enhancements w/ Common NOTIFY w/ Batched NOTIFY

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Experimental results:Experimental results:interinter--domain NOTIFY delaydomain NOTIFY delay

1

10

100

1000

6.6 8.6 10.9 14.6 w/p

ms

w/o service differentiation gold client silver client

NO

TIF

Y m

essa

ge

del

ay

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ConclusionsConclusions

Strong need for IMS scalable solutions– Both at the infrastructure and service level– Context- and service-aware approaches seem

to be promising and should not be neglected

Interoperability and standard compliancy– Full IMS standard compliance for

inter-domain optimization techniques – Ad-hoc solutions and integration with other

emerging standards at intra-domain level

Real-world testbeds should be employed whenever possible

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Research directionsResearch directions

Context-aware and self-* middleware solutions for service state management– Scalability is a complex and still open task

Session state grain/footprint/dissemination– Standard (r)evolution? (SIP, IMS, …)

Session control !!!!– Scalability first (millions/billions of nodes, systems of systems,…)

– Use and interaction with different standards Example: OMG Data Distribution Service (DDS) to ease

and boost context and presence data dissemination

And several others…

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Thank youThank you

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Many thanks go also toMany thanks go also to……

My research group and especially the B.Sc. and M.Sc. students who decided to collaborate with me on the IHMAS project– S. Parcaroli, G. Carella, R. Colombari, C. Pitscheider, L.

Scalorbi, F. Checchi, D. Campellone, and L. Nardelli

Professors A. Boukerche, S. Samarah, L. Mokdad, and A.-E. M. Taha for asking me to give this keynote speech

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IHMASIHMASproject web site and contacts project web site and contacts

Prototype code: http://lia.deis.unibo.it/Research/IHMAS

Contacts: Luca Foschini ([email protected])

Thanks for your attention!

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Some relevant references Some relevant references

G. Camarillo and M.A. García-Martín , The 3G IP Multimedia Subsystem (IMS) – Second Edition, Wiley, 2006.A. Dutta et al., “Mobility Testbed for 3GPP2-Based Multimedia Domain Networks”, IEEE Communications Magazine, vol. 45, no. 7, Jul. 2007.L. Skorin-Kapov et al., “Application-Level QoS Negotiation and Signaling for Advanced Multimedia Services in the IMS”, IEEE Communications Magazine, vol. 45, no. 7, Jul. 2007.T.T. Kwon et al., “Mobility management for VoIP service: Mobile IP vs. SIP”, IEEE Wireless Communications, vol. 9, no. 5, Oct. 2002.M. Stemm and R.H. Katz., “Vertical Handoff in Wireless Overlay Networks”, Mobile Networks and Applications, vol. 3, no. 4, Kluwer, Jan. 1998.M.E. Kounavise et al., “Design, implementation, and evaluation of programmable handoff in mobile networks”, Mobile Networks and Applications, vol. 6, no. 5, Kluwer, Sept. 2001.

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Some relevant references Some relevant references

V. Bharghavan et al., “The TIMELY adaptive resource management architecture”, IEEE Personal Communications, vol. 5, no. 4, Aug. 1998.H. Schulzrinne and E. Wedlund, “Application-layer mobility using SIP”, ACM Mobile Computing and Communications Review, vol. 4, no. 3, Jul. 2000.D. Vali et al., “An efficient micro-mobility solution for SIP networks”, IEEE GLOBECOM, 2003.S.K. Das, “SIP-based vertical handoff between WWANs and WLANs”, IEEE Wireless Communications, vol. 12, no. 3, Jun. 2005.N. Banerjee et al., “SIP-based Mobility Architecture for Next Generation Wireless Networks”, IEEE PerCom, 2005.C. Kalmanek et al., “A Network-Based Architecture for Seamless Mobility Services”, IEEE Communications Magazine, vol. 44, no. 6, Jun. 2006.A. Udugama et al., “NetCAPE: Enabling Seamless IMS Service Delivery across Heterogeneous Mobile Networks”, IEEE Communications Magazine, vol. 45, no. 7, Jul. 2007.

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Some of our recent contributionsSome of our recent contributions

P. Bellavista , A. Corradi, L. Foschini, “Context-Aware Handoff Middleware for Transparent Service Continuity in Wireless Networks”, Pervasive and Mobile Computing Journal, Elsevier Science, vol. 3, no. 4, Aug. 2007.P. Bellavista, A. Corradi, L. Foschini, “IMS-based Presence Service

with Enhanced Scalability and Guaranteed QoS for Inter-Domain Enterprise Mobility”, IEEE Wireless Communications Magazine, SI on Enterprise Mobility Services, vol. 16, no.3, Jun. 2009.P. Bellavista, A. Corradi, L. Foschini, “Enhancing the Scalability of

IMS-based Presence Service for LBS Applications”, IEEE COMPSAC, 2009.P. Bellavista, A. Corradi, L. Foschini, “Understanding and Enhancing the Scalability of IMS-based Services for Wireless Local Networks”, to appear as invited paper in the Proc. of IEEE WLN'09, held in conjunction with the IEEE LCN, 2009.P. Bellavista, M. Cinque, D. Cotroneo, L. Foschini, “Self-Adaptive Handoff Management for Mobile Streaming Continuity”, to appear in IEEE Transactions on Network and Service Management.

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