Interworking between P2PSIP Overlays and IMS Networks: Why? How? International SIP 2008 Interworking between P2PSIP Overlays and IMS Networks: Why? How? Enrico Marocco and Gianni Canal Telecom Italia Lab {enrico.marocco, gianni.canal}@telecomitalia.it

Outline Real-time communications are changing Peer-to-peer SIP Services vs. applications What has been done so far? What else can be done? Peer-to-peer SIP Why is it better than other technologies? P2PSIP/IMS interworking scenarios What is missing? Conclusions

What's happening to real-time communications? Telephony Service Providers Exploit IP to build one access- agnostic service architecture Legacy requirements Easy deployment of new services Enter the new (Internet) world e.g IM, Chat, Second Life Internet Companies Enrich the web experience with new and low-cost real-time communications applications e.g. GTalk, Yahoo! Big success factor: cheap calls towards regular phones e.g. Skype, SIPphone, Jajah

What can we do? Ignore Impede Leverage We cannot compete in the “Internet” world All in all, they push more bits in our pipes and pay us for call termination Impede Technically feasible Saved earnings exceed loss due to unsatisfied subscribers Leverage Let our subscribers call their “net buddies” Let third party applications access our telecom capabilities e.g. identity, voice-mail, payments, storage Take care of the “interconnection” part Provision of PSTN/PLMN interconnection requires big investments

What have we done so far? Branded VoIP+IM+telephone applications Better than the originals Connect with GTalk, Yahoo!, MSN [...] for free Let make calls just as regular phones! But users do not like them (YMMV)

The “Wengo” lesson One of the few Skype competitors Open source application bound to Wengo SIP service Free VoIP/IM, cheap calls/SMS Worldwide community Service ecosystem Wengo is NEUF Telecom... Direct connection with paying users vs. skypeout earnings, split between Skype and local operators ... but users do not feel it The operator can work as a back-end for communities Contribute resources and sell services Let the control to people

Dealing with people over the Internet Approach established communities Different technologies Need agreements Establish new communities Significant investment Extreme competition

Peer-to-peer SIP Hardware Bandwidth Fault Tolerance Configuration INVITE REGISTER INVITE REGISTER INVITE INVITE INVITE Fault Tolerance Configuration Management

P2PSIP: SIP for everyone Good for Internet companies/communities Build cheap solutions Public service providers Ad-hoc networks Small scale IP-PBX Connect with other networks Good for Telecoms Provide traditional services in other market segments Calls between phones and web applications Subscribers easily access their home network profiles Free competition for service provision e.g. interconnections, conferences, payments...  peer-to-peer  SIP  SIP  peer-to-peer

Calls between heterogeneous clients sip:alice@p2psip.org telecomitalia.it tel:+39-335-55-66-777 sip:bob@telecomitalia.it p2psip.org

Providing services to peer-to-peer clients sip:alice@telecomitalia.it sip:alice@p2psip.org REGISTER sip:p2psip.org SIP/2.0 To: sip:alice@p2psip.org From: sip:alice@p2psip.org Contact: sip:alice@172.16.0.123 telecomitalia.it REGISTER sip:telecomitalia.it SIP/2.0 To: sip:alice@telecomitalia.it From: sip:alice@telecomitalia.it Contact: sip:alice@p2psip.org p2psip.org

Gaps P2PSIP IMS Traffic relay in limited connectivity environments Global reachability (DNS) Service discovery IMS IPv4/IPv6 gateways NAT traversal enabled on clients SIM-less authentication Peering policies

Conclusions Differentiation in real-time communications “Services and applications” better than “services vs. applications” “Offer” rather than “control” to succeed on the Internet P2PSIP can enable IMS-friendly cheap communication services P2PSIP overlays can be a marketplace for telecom operators Topical issues to be addressed in IETF and 3GPP