MASSACHUSETTS INSTITUTE OF TECHNOLOGY HAYSTACK OBSERVATORY WESTFORD, MASSACHUSETTS July 2002

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1 MASSACHUSETTS INSTITUTE OF TECHNOLOGY HAYSTACK OBSERVATORY WESTFORD, MASSACHUSETTS TO: FROM: SUBJECT: Distribution Alan R. Whitney 12 July July 2002 e-vlbi telecon summary Telephone: Fax: Attendees: Lee Foster, Bill Fink, Pat Gary, Kevin Kranacs, Paul Lang GSFC Steve Bernstein, Lorraine Prior, Peter Schultz Lincoln Laboratory Tom Lehman ISI-E Richard Crowley, Hans Hinteregger, Arthur Niell, Mike Titus, Alan Whitney Haystack Observatory This telecon is one of an ongoing series of telecons to prepare for gigabit/sec e-vlbi demonstrations between NASA GSFC and MIT Haystack Observatory using a combination of network facilities including all or part of Glownet, Bossnet, ISI-E, SuperNet, Max and GSFC/HECN. Status Reports The attached figures of the e-vlbi path have been updated to reflect current status and are pretty much self-explanatory; critical status items are indicated in red. In addition, the following comments are relevant: Peter reported that there is still a problem with the Bossnet service and LL is short of personnel to address the problem immediate. As a result, Bossnet will be maintained as a link until at least August. The link seems to be working properly and is suitable for the e-vlbi demonstration; however, the Bossnet link is shared with MIT campus, so Bossnet use for e-vlbi needs to be scheduled (via Bossnet scheduling calendar) so that campus activity can be suspended while e-vlbi testing takes place. The Bossnet problem appears to be somewhere in the path between New York and Newark, but is not yet isolated. Router configurations at G10, H3 and H7 have been updated, as promised at the last meeting, for e-vlbi use. workstation at K6 is now named clifford (not dawg ). Alan will update on workstation specification list. Lorraine reported that another LL demonstation using Glownet is scheduled for 22 July, during which time Glownet will be unavailable for e-vlbi. Haystack target date is tentatively August for full demonstration. 1

2 Performance ing Bill F. requested that all test workstations install a nuttcp server to facilitate ease of testing. He will distribute a note to everyone with details of the installation procedure (has been done). Kevin D. conducted several short tests from Haystack ( evlibhay ) to GSFC/GGAO ( pluto ), achieving ~350 Mbps throughput. Below is a summary of his results: Configuration MIT(evlbihay): ip mtu 4470 (9000 max) mss 4418 /proc/sys/net/core/wmem_max /proc/sys/net/core/rmem_max /proc/sys/net/ipv4/tcp_timestamps 1 /proc/sys/net/ipv4/tcp_sack 1 /proc/sys/net/ipv4/tcp_wmem " " /proc/sys/net/ipv4/tcp_rmem " " nuttcp v3.1.9 Configuration GGAO(pluto): ip nuttcp v3.2.1 Rtt: ~ 15 msec Throughput: ~ 350 Mb/s (Haystack to GGAO) Note: Only very short duration (1-15 secs) tests were done. The following was typical output: [kad@evlbihay bin]$./nuttcp -t -l4418 -n w2048 -ws nuttcp-t: v3.1.9: socket nuttcp-t: buflen=4418, nbuf=16384, nstream=1, port=5001 tcp -> nuttcp-t: connect to nuttcp-t: send window size = , receive window size = nuttcp-t: MB in 1.64 real seconds = KB/sec = Mb/s nuttcp-t: I/O calls, msec/call = 0.10, calls/sec = nuttcp-t: 0.0user 0.3sys 0.01real 21% 0i+0d 0maxrss 0+0pf 0+0csw nuttcp-r: v3.2.1: socket nuttcp-r: buflen=4418, nbuf=16384, nstream=1, port=5001 tcp nuttcp-r: accept from nuttcp-r: send window size = 16384, receive window size = nuttcp-r: MB in 1.68 real seconds = KB/sec = Mb/s nuttcp-r: MB in 0.22 CPU seconds = KB/cpu sec nuttcp-r: I/O calls, msec/call = 0.10, calls/sec = nuttcp-r: 0.0user 0.2sys 0:01real 13% 0i+0d 0maxrss 1+1pf 0+0csw Kevin D. feels that there may some tuning issues on pluto, but he was unable to get a password to make tuning changes. Bill F. will work with Kevin on pluto tuning issues. Tom also suggested trying a multi-stream TCP process to improve aggregate throughput rate (easily done with nuttcp). nuttcp is not yet ported to Windows. Lee reports that a summer student is currently working on this project. Tom will investigate possibility of putting nuttcp on MAX test workstations, but warned that these machines are not particularly high-performance machines so probably may not be able to draw useful performance conclusions. 2

3 Tom and Bill will coordinate increasing mtu size on paths between ISI-E and MAX. The issue is complicated by the use of frame relay encapsulation on some of these links and links to Abilene. Action Items Bill F: Distribute information on nuttcp routine (has been done). Tom/Bill F.: Will coordinate installation of nuttcp on ISI-E test machines (Tom will be on vacation for next two weeks, but will be available via occasionally during this time). Bill will then do testing on ISI-E/GSFC link and report to group. Tom/Bill F.: Will coordinate mtu change on ISI-E/MAX links. Tom: Will investigate possibility of putting nuttcp on MAX test workstations. Kevin D./Bill F.: Will coordinate to allow Kevin access to pluto (requires Kerberos account). Next telecon Next telecon will be Wed, 7 Aug 2002 at 2 pm. xc: Steve Bernstein, LL Jim Calvin, LL Lorraine Prior, LL Leslie Weiner, LL Herbert Durbeck, GSFC Lee Foster, GSFC Pat Gary, GSFC Chuck Kodak, GSFC Kevin Kranacs, GSFC Paul Lang, GSFC Aruna Muppalla, GSFC Bill Wildes, GSFC Dan Magorian, UMCP Tom Lehman, ISI Jerry Sobieski, Max Richard Crowley, Haystack Kevin Dudevoir, Haystack Hans Hinteregger, Haystack Arthur Niell, Haystack Joe Salah, Haystack 3

4 / A1 Westford Antenna A2 1i 1 8 A3 Dedicated - no scheduling A4 Millstone RPE Bldg (Lorraine) C1 Alpine 3804 Schedule to be coordinated with LL LL Dell Poweredge 2500 ( evlibhay ) 1500 / / Schedule to be coordinated with LL E5A E1 B1 B3 From ISI-E E2 E4A ( superglide ) Haystack Correlator 28-1A B2 28-1B B GlowNet Lincoln Lab (Lorraine/Steve/Jim) E3 Alpine 3804 E4 ( evlbill ) 100 Mb E5 Dell Poweredge 500SC (provided by Haystack) B5 B7 E6 Dedicated - no scheduling B8 Hub B10 B9 To HS switch D3 M20 E7 MIT Campus Corr Cntl Cmptr 1310 E8 B11 E9 F1 Other users(no control) To be upgraded to Congress St Boston 155x GlowNet Figure 1: e-vlbi Path - Haystack to ISI-E B6 D2 D1 Bossnet (Steve/Jim) C3 C2 (~50 km) (~100 km) Shared with MIT traffic Scheduling on Bossnet calendar F2 Bossnet currently running pending investigation and repair (Shared with LL on scheduled basis) (2 + 1 ) ISI-E evlbi011.cdr 12 July 02

5 Bossnet Scheduling on Bossnet calendar Tuner G2 Transponder G7 ( omega ) ISI-E GE G6 (Tom) G5 G8 G9 G7B ( kame ) GE G6B G4 G6C M40 G12 Switch Backup plan H2 Borrowed interface - may not be able to keep G1 G3 G10 H3 G11 H1 Frame relay encapsulation ISI-E(Jerry) H5? M160 H4 MAX performance node; need details No scheduling; sufficient capacity for e-vlbi LX (~14km) MAX/UMCP(Jerry/Dan) No jumbo frames Other users ( no control) H7 J J5 H8 J4 Switch H9 on loan from GSFC M160 H11 Primary e-vlbi path J2? H10 LuxN Need details J1 J6 H6 2 s GSFC/Bldg 28 (Pat/Paul/Kevin/Bill F.) GGAO/Bldg 201 (Pat/Chuck) GGAO Antenna Trailer (Bill W./Chuck) Will try to schedule either K2 or K3 exclusively for e-vlbi experiment G4 Mac with Yellowdog Linux ( clifford ) K1 K2 K3 K6 K5 Windows PC ( xly ) K4 K6A K5A K5B K6B 1310 LX (~7.25km) Dedicated - no scheduling necessary (~500m) Figure 2: e-vlbi Path - ISI-E to GSFC/GGAO K7 L1 L2 L3 L5 G4 Mac ( pluto ) SX L4 L6 evlbi012.cdr 12 July 02