Technology and Administrative Coordination Issues Pacific Rim Networking Workshop Guy Almes Manoa Valley, Oahu 22 February 2002

Internet2 Engineering Objectives Provide our universities with superlative networking: Performance Functionality Understanding Make superlative networking strategic for university research and education

Technology Issues Multicast IPv6 Performance Measurement Security

Multicast Any Source (Conventional) IPv4 Multicast Steve Deering's PhD thesis from Stanford Led to MBONE, then native IP multicast PIM-Sparse, MBGP, and MSDP Technical Implications Group g has global significance Host s creates and joins g and can both send and receive packets Other hosts can join g and can both send and receive packets MSDP needed to discover the source(s) sending to g Each host receives packets from

Issue: Global deployment Careful inclusion of ASM IPv4 Multicast in international peering Inclusion of multicast issues on local campuses Bandwidth must be sufficient for all sources to all destinations Allocation of group IDs

Issue: Multicast Applications Access Grid and DVTS: distance education and conferencing among sets of collaborators Streaming Audio/Video Sending files to many destinations, as with Digital Fountain

Issue: Scalability and SSM Recall implications of ASM Global Significance of 'g' value Any host can join/send to group g SSM being deployed to resolve this Host s creates a channel Others can subscribe to, but only s sends Source discovery now trivial, so MSDP not needed g now only has local significance Easy to support in wide area, but new IGMP needed Applications need to be adapted

IPv6 Clarify motivation for IPv6 End-to-end transparency and global addressability Supports application innovation, e.g., peer-to-peer Support deployment and engineering expertise on networks, especially on campus Anticipate need for first-class support E.g., 10 Gb/s Abilene upgrade E.g., Linux, Windows XP

Issues: Training Within Internet2, IPv6 Training Workshops About 8-10 workshops this year First: in Los Angeles, hosted by CENIC, in February

Issue: Deployment Get some IPv6 on each campus/NRN Tunneled IPv6 over IPv4 works well Performance and network management are limited, however Prepare for native peering Abilene will be native IPv6 as part of current upgrade Implications for router selection! Explore applications, DNS, operational stability, multicast

Issue: Performance Tunnels limit performance dramatically About 30 Mb/s on Cisco 7200, for example Some tunnels will exist for some time But, we must remove tunnels in all performance-sensitive paths Thus, remove tunnels from key wide-area connections

Issue: Operations IPv6 needs to become a 'normal' protocol Robustness of DNS etc. Mature network management etc.

End-to-End Performance: Bandwidth In former times, very low bandwidth led to (correctly) low expectations Now, serious bandwidth exists TransPac deployment of two OC-12 representative Bandwidth growth will likely continue North America to Europe as a challenging example

End-to-End Performance: Latency Bandwidth is not the only issue Neither the speed of light nor geographical distance across the Pacific have improved! Thus, round-trip times cause problems: Sluggish TCP convergence Interactive applications more difficult Thus, direct physical paths needed Hawaii can play a role here

End-to-End Performance: Packet Loss TCP Throughput MTU / (RTT * PacketLoss) This packet loss include that due to: Congestion Other sources Thus, we need to remove any source of non-congestive packet loss

End-to-End Performance: MTU There is almost always an Ethernet link somewhere along a wide-area path, hence end-to-end MTU seldom more than 1500 But larger MTUs are supported on wide- area links, e.g., 9180 on Abilene When performance really matters, work to support large end-to-end MTUs

Threats to End to End Performance Fiber problems dirty fiber dim lighting 'not quite right' connectors

Threats to End to End Performance Fiber problems Switches horsepower full vs half-duplex head-of-line blocking

Threats to End to End Performance Fiber problems Switches Inadvertently stingy provisioning mostly communication happens also in international settings

Threats to End to End Performance Fiber problems Switches Inadvertently stingy provisioning Wrong Routing asymmetric best use of Internet2 distance

Threats to End to End Performance Fiber problems Switches Inadvertently stingy provisioning Wrong Routing Host issues NIC OS / TCP stack CPU

Perverse Result 'Users' think the network is congested or that the Internet2 infrastructure cannot help them 'Planners' think the network is underutilized, no further investment needed, or that users don't need high performance networks

Measurements Traffic utilization MRTG, etc., need to be more visible Performance-related measurements iperf, AMP, Surveyor, etc. along key paths Passive measurements Netflow becoming mature OC3MON hardware-based sampling of actual packets Router support becoming available

Security

Security: An unusual Internet2 Emphasis Aspects of Security Security of the infrastructure Security of user host computers Security of information and privacy In the post-11-Sep environment Society will be less tolerant of lax standards Not a distinctly 'Internet2' concern but one that all our universities share