1. Technology for Using High Performance Networks or How to Make Your Network Go Faster…. Robin Tasker (r.tasker@dl.ac.uk) UK Light Town Meeting 9 September 2004

2. Presenter Name Facility Name One Terabyte of data transferred in less than an hour On February 27-28 2003, the transatlantic DataTAG network was extended, i.e. CERN - Chicago - Sunnyvale (>10000 km). For the first time, a terabyte of data was transferred across the Atlantic in less than one hour using a single TCP (Reno) stream. The transfer was accomplished from Sunnyvale to Geneva at a rate of 2.38 Gbits/s Throughput? What’s the problem?

3. Presenter Name Facility Name Just the Internet2 Land Speed Record… OK We can get transatlantic rates of 6.5 Gbits/s, but how was that done? What’s the magic? So you thought 2.38 Gbits/s was good?

4. Presenter Name Facility Name Internet Regional Campus Client Server Just a Well Engineered End-to-End Connection End-to-End “no loss” environment from CERN to Sunnyvale! At least a 2.5 Gbits/s capacity pipe on the end-to-end path Processor speed and system bus characteristics TCP Configuration – window size and frame size (MTU) Network Interface Card and associated driver and their configuration A single TCP connection on the end-to-end path Memory-to-Memory transfer; no disk system involved No real user application That’s to say the devil is in the detail… Sorry. No magic here…..

5. Presenter Name Facility Name Campus Client Server UK Light Just a Well Engineered End-to-End Connection End-to-End “no loss” environment At least a 2.5 Gbits/s capacity pipe on the end-to-end path Processor speed and system bus characteristics TCP Configuration – window size and frame size (MTU) Network Interface Card and associated driver and their configuration A single TCP connection on the end-to-end path Memory-to-Memory transfer; no disk system involved No real user application Even with UK Light, the devil is in the detail …and it’s harder! And how about the same across UK Light?

6. Presenter Name Facility Name The Easy Bits…. :-) End-to-End “no loss” environment At least a 2.5 Gbits/s capacity pipe on the end-to-end path Processor speed and system bus characteristics TCP Configuration – window size and frame size (MTU) Network Interface Card and associated driver and their configuration

7. Presenter Name Facility Name Read the Details Here http://grid.ucl.ac.uk/nfnn.html

8. Presenter Name Facility Name Now for the hard bits…

9. Presenter Name Facility Name A Single TCP Connection

10. Presenter Name Facility Name Fortunately there’s good news! Standard TCP Recovery >10 minutes Scalable TCP Very rapid recovery High Speed TCP Rapid recovery Comparison of TCP stack performance under loss rate of 1 in 10**6, RTT=108ms

11. Presenter Name Facility Name Memory to memory; no disk system High Speed TCP transfer using Iperf, i.e. no disk system and no application Web100 records of High Speed TCP during a http-Get data transfer, i.e. disk system but no application

12. Presenter Name Facility Name Understanding disk systems

13. Presenter Name Facility Name No real user application High Speed TCP transfer using Iperf, i.e. no disk system and no application Web100 records of High Speed TCP during a http-Get data transfer, i.e. disk system but no application Web100 records of High Speed TCP during a GridFTP data transfer, i.e. disk system and real user application

14. Presenter Name Facility Name Understand your Application It’s YOUR application, so remember Three Golden Rules Benchmark! Benchmark!! Benchmark!!!

15. Presenter Name Facility Name Book Early!!! - Provisionally - Tuesday 1 st – Wednesday 2 nd March 2005 NeSC http://grid.ucl.ac.uk/nfnn.html