Trends in Network Evolution Igor Faynberg, Ph. D. Hui-Lan Lu, Ph. D. Bell Labs, Lucent Technologies Multimedia Convergence Workshop Geneva, 2002 Slide 1, hlu & faynberg
Outline l Introduction l Internet – – Original Requirements Architectural Principles Hourglass model New requirements l Some observations l An evolvable solution Slide 2, hlu & faynberg
An Increasingly Connected World l A century to install the world’s first 700 3 l About a billion wireless subscribers in the world today, growing about 20% per year Billions million phone lines; 700 million more lines over the next 15 -20 years 2 Global Access Lines Wireless Cable Wireline 1 l About 300 million Cable TV subscribers in the world today, growing about 6% per year 0 1958 l More than 400 million Internet users in the world today, growing about 20% per year – enough to circle the globe 2250 times – bringing the installed base to about 400 million km Millions l 90 million km of fiber deployed in 2000 1998 2005 Global Internet Users 800 600 400 200 0 Slide 3, hlu & faynberg 1978 1995 2000 2005
Requirements for the Original Internet high importance l Existing networks must be interconnected with an effective multiplexing technique l The interconnected network must continue to function despite partial network failures l The resultant architecture must low importance Slide 4, hlu & faynberg – Support multiple types of communications applications – Accommodate a variety of networks – Permit distributed management of its resources – Be cost effective – Permit host attachment with a low level of effort – Be able to account for the resources used
The Internet A basic component is routers, which interconnect distinguishable networks by storing and forwarding packets . . . IP Network 1 Gateway IP Network 4 IP Network 2 IP Network 3 Slide 5, hlu & faynberg
Internet Architectural Principles (RFC 1958) l Emphasize intelligence at the edges (i. e. , fate sharing), sharing distributed processing, dynamic (versus static) solutions, and modularity l Support accommodation of multiple network types l Are inherently hostile to the needs of Internet-wide realtime multimedia applications l Are not a religion (RFC 1958 is informational) Slide 6, hlu & faynberg
The End-to-End Argument The function in question can completely and correctly be implemented only with the knowledge and help of the application standing at the end points of the communication system. Therefore, providing that questioned function as a feature of the communication system itself is not possible. (Sometimes an incomplete version of the function provided by the communication system may be useful as a performance enhancement. ) (J. H. Saltzer et al. , “End-to-end Arguments in System Design”) l Move functions up and out l Make the network as transparent as possible Slide 7, hlu & faynberg
The Internet Hourglass • A single data delivery • • • service at network layer maximizes interoperability and minimizes the number of service interfaces Minimum function (besteffort packet forwarding) at network layer allows the network to scale easily A single global address space is accessible to all Shielding network details from upper layers fosters application innovation Slide 8, hlu & faynberg email WWW telephony. . . SMTP HTTP RTP. . . TCP UDP… IP 802. 2 PPP… CSMA SONET. . . copper fiber radio. . . (Source: Steve Deering’s presentation at the IAB Plenary, 51 st IETF )
Out of Shape? email WWW telephony. . . SMTP HTTP RTP. . . TCP UDP… IP + mcast IP ATM IP + Qo. S +. . . 802. 2 PPP… CSMA SONET. . . copper fiber radio. . . (Source: Steve Deering’s presentation at the IAB Plenary, 51 st IETF ) Slide 9, hlu & faynberg
Factors Changing the Internet l Growing size of the routing table l More-demanding applications, such as – Media streaming – Multimedia conferencing l New types of endpoint devices, such as – Personal digital assistants – Cell phones – Appliances l Assured operation in an untrustworthy world l Service provider service differentiation l 3 rd party intervention (e. g. , wiretapping) l Less-sophisticated users Slide 10, hlu & faynberg
Some Observations l IP has become the public UNI for networking-service access. l Separate specialized networks are evolving to multi-service networks that have a packet/optical core. l MPLS is a key technology to enable the packet core to deliver better- than-best-effort, manageable and billable services. l The synthesis of the Internet philosophy (Intelligence only at the edges) and Telecom philosophy (Intelligence only at the network) is Global Services through coexistence and cooperation of the Intelligence in Networks with the Intelligence at the Edges! l National and international regulations are adapting to address issues on, for example, open access, fair competition, intellectual properties rights, security and privacy. l The standards organizations should cooperate in defining interfaces and building blocks for ubiquitous intelligence. Slide 11, hlu & faynberg
An Evolvable Solution --Intelligence in every layer Control Bearer Application Layer Application Services Internet Service Control Layer Softswitch Control IP Service Switching Network Transport Layer Media Gateways PSTN Broadband Access Multiservice Packet Switching RAS X DSLAM Gb. E Frame/ ATM Access Network CPE Wireless Slide 12, hlu & faynberg X Metro Optical X X X Optical Core X Core network X X
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