Language / 言語
This seminar will be held in English only. / 今回のセミナーは英語での進行となります。
Ulrich Speidel (Department of Computer Science, The University of Auckland)
In many small Pacific Island countries, remoteness, deep ocean and low GDP put international submarine cable connectivity out of reach, and satellite Internet is the only option. However, satellite bandwidth is expensive: typical ISP capacities are between 8 and < 100 Mbps on geostationary satellites, and a few hundred Mbps on medium earth orbit satellites. These are often shared between dozens if not hundreds of end users. This bottleneck, along with the significant latency of satellite links, conspires badly against TCP senders and islanders: Many flows never get to open their congestion windows, those that do do so only very slowly, and TCP queue oscillation is rife. Many links are badly underutilised as a result. Potential solutions are at hand in the form of performance-enhancing proxies (PEPs) and forward error correction across packets and the satellite link input queue - but how can we tell how well they might work? To answer such questions, we have built a satellite network simulator at the University of Auckland. The simulator is largely hardware based, with 84 Raspberry Pis and 10 Intel NUCs providing client demand on the "island side", one dedicated Super Micro Server simulating the satellite link itself, one Super Micro on either side providing coding and/or PEP services, and 14 further Super Micros providing "world" TCP traffic to the island at avariety of "terrestrial" latencies. My talk will cover our simulation approach, our current results, challenges faced and lessons learned so far.
Date and Time
- 2017-7-12 (Wed) 14:30 (The registration desk opens at 14:00)
- Internet Initiative Japan Inc. 13F Opera2 room
- Iidabashi Grand-Bloom 2-10-2 Fujimi, Chiyoda-ku, Tokyo 102－0071
Read before comming
- Registration is required to enter the office floor of the building. A registration desk for the seminar participants will be located on the second floor of the building. Please state your name to the staff and receive a visitor card key.
- The registration desk will be opening around 15 minutes before the seminar starts.
- If you've arrived at the building after the registration desk has closed, please call the phone number printed on the signboard at the registration desk.
- We will collect your visitor card key before you leave the meeting room. Please hand your key to the staff standing by the room exit.