Design and Implementation:Large Scale IPv6 Multimedia Communication

System based on SIP

David Gong27,8. 2007

Outline

• Background• Available Research• System Design• Key Implementation-SIP6• Performance Test• Conclusion • Future Work

Background• What is SIP?– SIP is a protocol defined to establish, modify and tear

down multimedia communications over Internet• CERNET2– Currently the largest pure IPv6 network of world, various

kinds of applications are explored on CNGI• Existing SIP Deployment– SIP.edu– VoIPv6 of 6Init– SIP over IPv6 in Taiwan

• SIP Server would turn out to be a performance bottleneck when largely deployed

Existed Researches• Increases capacity of single SIP server

– A hybrid transaction proxy algorithm• Load Balancing

– DNS SRV– IP Virtual Server– CINEMA[2]– Performance Optimization or need extra resources

• P2P based SIP systems– CASIP– P2PSIP– P2PSIP using OPENDHT | Chord– Still far from large scale deployed

System Design

• Design Principles• System Architecture• Global Unique Identifier• Load Balancing Mechanism• High Available AoR Database Mechanism

Design Principles

• Pure IPv6 Solution– All key components run on IPv6 stack• Take advantage of IPv6• Expose any potential disadvantage of IPv6

• Scalability, Robustness and Roaming Support – Geographically distribution of subscribers– Roaming Potential• Rapid deployment of WIFI network in China

System Architecture• Hybrid arch: distributed routing, centralized AAA

Global Unique Identifier

• The identifier of subscriber has to be global effective to support roaming and load balancing

• Every SIP server has to know where to lookup the AoR of destination and where the next hop is

• A Global Unique Identifier is indispensable xx-xxxx-xxxxx

Load Balancing Mechanism-1• DNS SRV Mechanism– Advantage: standard, support by SIP…– Disadvantage: Local user gets served by distant

server -> poor QoS

• Our Proposal – Carrying location information of SIP servers in

SRV’s weight fieldDNS SRV weight field “a012”

Location bits “a0”

Weight bits “12”

Load Balancing Mechanism-2

• Allocation of location bits– Each region is mapped

to a scope of location bits

– The location bits are adjusted according to the actual load• Load bits of overloaded

SIP server will slide to adjacent location bits

High Available AoR Database Mechanism

• General Hash Mechanism– GNI hashed to various databases

• Failure of any node would influence a series of users• Out Scheme– Store redundant AoR in different databases

• Primary database and secondary database are introduced• Primary index and Secondary index are determined by GNI• Primary index is related to location, to optimize performance• Secondary index is hashed as distributed as possible

• Usage– Store: parallel, both– Fetch: serial, stop if the fetch of primary database succeed

Key Implementation

• Network Environment• Hardware and Software Platform• Global Unique Identifier of SIP6• DNS SRV mechanism for SIP6• AoR Databases Mechanism for SIP6• Current Progress

KImp - Network Environment

• All components connected to backbone of CERNET2 directly

• Domain Name: sip6.edu.cn

Hardware and software Platform• Hardware– Sun X2200

• OS– Redhat AS 4.1

• SIP Server– Fully support of IPv6– Extended DNS SRV mechanism– High Available AoR Database Support– OPENSER

• Database– POSTGRESQL

Global Unique Identifier

• Potential users would be aggregated around universities

• The GUI of users from certain univ. is designed be consecutive.

86-0001-12345

Country Code University index Subscriber ID

DNS SRV for SIP6

• 3 Region in the first deployment stage• Initial distribution of location bits:– 0 - 120; 80 – 200; 160 – 256;

– SIP Server1 gets overload, SIP server2’s location bits is adjusted to 100:

_sip._udp 3600 SRV 15370 0 5060 sip-server1.sip6.edu.cn._sip._udp 3600 SRV 35850 0 5060 sip-server2.sip6.edu.cn._sip._udp 3600 SRV 56330 0 5060 sip-server3.sip6.edu.cn.

_sip._udp 3600 SRV 15370 0 5060 sip-server1.sip6.edu.cn._sip._udp 3600 SRV 35850 0 5060 sip-server2.sip6.edu.cn._sip._udp 3600 SRV 56330 0 5060 sip-server3.sip6.edu.cn.

_sip._udp 3600 SRV 25610 0 5060 sip-server2.sip6.edu.cn_sip._udp 3600 SRV 25610 0 5060 sip-server2.sip6.edu.cn

Current Progress

• Website: http://register.sip6.edu.cn• IPv6 SIP User Agent: CoolSIP– Voice, Video, IM, PSTN…

Performance Test

• Test Case– Registration test– Invitation test

• The test result is average value of single server

Test Parameter

Network Connection 1Gps

SIP Load Generator Sipp2.0(no DNS SRV support)

Load Generator hardware Sun X2200

retransmission timer 500ms

Registration test Pre-created account(10000) expire timer: 20s

Invitation test Pre-registration(10000 account) call duration: 1ms

Registration Test

• Number of Test – 200,000

registration

• Test Duration– 1m 46s

• Average cps– 1879

Call Duration Call Number

0ms <= n <= 10ms 0

10ms <= n <= 50ms 612

50ms <= n <= 100ms 169074

100ms <= n <= 150ms 11202

150ms <= n <= 200ms 1

200ms <= n <= 500ms 444

500ms <= n <=1000ms 8492

1000ms <= n <= 2000ms 5760

n >= 2000ms 3126

Table 1. Registration response time distribution

Invitation Test

• Test Number– 40,000 calls

• Test Duration– 42seconds

• Average cps– 982

Call Duration Call Number

0ms <= n <= 10ms 30

10ms <= n <= 50ms 1272

50ms <= n <= 100ms 4479

100ms <= n <= 150ms 10864

150ms <= n <= 200ms 11072

200ms <= n <= 500ms 8653

500ms <= n <=1000ms 8492

1000ms <= n <= 2000ms 3481

n >= 2000ms 356

Table2. Call Duration Distribution

Conclusion• Presented an innovate SIP architecture– Totally IPv6 Solution– Extended DNS SRV Mechanism– High Available AoR Database Mechanism

• Exhibited SIP6’s deployment on CERNET2– Take advantage of the distribution of subscribers– Take advantage of open source software

• Performance Test– Registration test– Invitation test

Future Work

• Test and Analysis of performance decrease due to introduction of second database mechanism

• The influence on SIP Traffic caused by DNS SRV self adjustment

• Using a DNS SRV enabled sipp to do further test– Develop a DNS SRV supporting patch for sipp

• Collect running data from operational system• Analysis the influence of message and presence

Reference• SIP: Session Initiation Protocol, RFC3261• SIP.edu http://www.internet2.edu/sip.edu/ • Mauricio Cortes, Jairo Esteban, and Hyewon Jun, Towards Stateless Core:

Improving SIP Proxy Scalability, In IEEE Globecom Conference, November, 2006

• Kundan Singh and Henning Schulzrinne, Failover and load sharing in SIP telephony, Technical Report 2005

• P2P SIP, http://www.p2psip.org/ietf.php

Thank you && Questions?