A requirements based assessment of SIP servers

Transcription

1 A requirements based assessment of SIP servers Samuli Pöykkö, Supervised by Professor Jörg Ott

2 A three part presentation SIP Pragmatic problem An assessment Requirements Services in literature Interviews Findings Servers

3 Session Initiation Protocol A technology for setting up rendezvous, connecting people and also, limitedly, discovering resources.

4 Session Initiation Protocol Origins in multimedia and conferencing Is not SS7 Developed by the Internet Running Code Although it has some common applications Setup signalling Session modification Network applications (IN)

5 Session Initiation Protocol Deployed with architecture A User Agent has a function or functions Proxy Register / Registrar Directory B2BUA

6 A deployment UA Proxy Registrar UA The proxy and registrar functions relate to administrative domains A domain could be further controlled using a border controller Network applications are likely to be implemented in specialised functions (Application Servers) In theory, media flows from UA to UA, but a media resource function could also be used

7 Session Initiation Protocol Adds Internet Multimedia Signalling is now separated from the media, media can be anything I ll bring video, you can bring text, voice or even a game let s have a session in a fridge

8 Session Initiation Protocol And crafted for extensions The HTTP-like syntax can be amended with extensions such as new methods and headers New features i.e. services Quality control through process instructions for authors The number of methods and headers has already been doubled (From 6-9 to 14 and 52 to 92) Notification framework Instant messaging 3 rd party call control and conferencing in the works Also ways to fix the protocol (GRUU, STUN)

9 Introduction Background in personal interests Where are the current SIP products in relation to the present day requirements? What are the requirements? Also, SIP seems to be the key for VoIP, but what about the other uses, services from a third party and other contemporary strategies?

10 Interview indings Need for services Demand for telephone services is driven by general knowledge and maturing of the technology Few differences to trade show presentations propose Meeting growing demand with present services, it seems that there is no rush Possible new services ENUM, inter-operator calling, Multimedia in end devices, Video calls, Free video calls, Presence, Interworking of Bluetooth and presence, Triple play and device independency in general, SIP integrated communities, Film festival on-demand, Family presence and IM, Role playing games, Service roaming across devices, PBX features, Personal voice mail, Access lists, Configurable call processing, Short dialing, Personal dialing plan, Controlling home automata (sauna, fridge, etc.), Implementing 3G services Potential VAS Mobility, Presence, Web enabled 3PCC: Collect call as 3PCC, Virtual mobile PBX, (Home) surveillance, Voice mail, Intelligent call forwarding, Video Messaging

11 Findings Perceived competition Disagree Agree Disagree Agree This area of the insdustry suffers churn There are substitutes Standards make it easy to find substitutes

12 Servers Established market Around two dozen potential AS candidates Some consolidation Vendors with different backgrounds Current offerings neither fully satisfy the users nor present immediate aches Decomposed for comparison to requirements

13 Requirements Engineering Way of managing needs, evaluating fitness Engineering process includes 1. Elicitation 2. Analysis Elicitation techniques and sources for needs include 1. Interviews 2. Secondary material Standardisation adds delay

14 Requirements Engineering (2) Analysis outputs different requirements Constrains for acceptance Testable requirements Requirements Functional Non-functional Qualities General constraints

15 Services in literature Standards literature includes requirements Work of SIPPING group of the IETF The Service examples memo Requirements include example uses, recommended implementation Also, standards can be searched for service ideas But are Centrex, multi-party calls, IM enough? Services in the standards can be turned in to constraints and functional requirements New services from the interviews should be proposed to SIPPING

16 Interviews and qualitative methods usual in many sciences In Requirements Engineering, interviews can complement secondary sources Face to face discussions Interview methods vary in how open questions are included Open- and Closed-ended questions Structured and unstructured interviews Semi-structured framework provides context Suggested for RE Discovering the unexpected Interviews

17 Interviews (2) Interviews with new service providers Essentially one question Five-page questionnaire was inspired By SW engineering practices Strategic Management Preparing for nonideal answers Providing immediate feed back Dry runs invaluable

18 Service provider roles Cost leaders and specialists Low cost challenger - Tactical investments case by case and however cheapest, opportunities Infrastructure builder - Offering based on current resources, efficient use, honing the platform, cautious about competition Premium entertainer - Services as the key differentiator, an unique offering, ease of use Smooth operator COTS, honing processes, selected markets (research, segmentation, marketing), new services to bring premium Cost leader SME challenger Smooth operator Specialist Infrastructure builder Premium entertainer

19 Conclusions and future work Servers from larger, multi-national, vendors are hard to investigate Offerings cover a large area of business, corporate IT from end to end Individual features (such supported standards) are minor details ( all relevant RFCs ) Vendors might compete with the operators in the business segment Other vendors seem to follow either a signalling oriented or a service creation oriented approach Are SIP Servlets a method with enough processing power alone or do these servers need to be complemented with routing functions? It is possible to create mappings between services and servers Considering how roles are connected to services and requirements, availability of servers might have effect on roles Server 1 Server 2 S3 S4 B2BUA SIMPLE REFER 3PCC CPL GRUU DTMF Music-on-hold Voice portal Messaging..

20 Thank you for your participation Any comments on the presentation? Creative Commons licensed photographs Early morning #1 by Danny Wartnaby Hotline by Grant Hutchinson Freedom fighters by Children at Risk Foundation Miniature TATE Modern by Jean Burgess Work Work Work by Lies Van Rompaey Listen Carefully by 416style / sookie