Trial on the Efficient Use of Trunk Communcation Lines for VLBI
in Japan
Noriyuki Kawaguchi
NATIONAL Astronomial Observatory,Japan
eVLBI Workshop2008.6.17@Shanghai Observatory
Contents
(1) 10GbE connection with variable bit rate Kashima 34m and Koganei 11m
(2) L1 on-demand connection Yamaguchi 32m and Tsukuba 32m
(3) Link Aggregation of multiple GbE links Tomakomai 11m access link
Test Fields in Japan
Tomakomai11m
Hokkaido UniversitySapporo
Kashima34m
Koganei11m
L1 on-demand
Yamaguchi32m Tsukuba
32m
GbE Aggregation
10GbE connection
10GbE Connection
D Port #1
C Port #1
D Port # 2
C Port # 2
D Port # 3
C Port # 3
D Port # 4
C Port # 4
VSI(DIM,2048Mbps)ADS-1000
VDC-100F VSI(DOM,2048Mbps)
VSI(DIM,2048Mbps)ADS-1000
VDC-100F VSI(DOM,2048Mbps)
VSI(DIM,2048Mbps)ADS-1000
VDC-100F VSI(DOM,2048Mbps)
VSI(DIM,2048Mbps)ADS-1000
VDC-100F VSI(DOM,2048Mbps)
Cont. CPU
GbE
10GbE10G-BASE-LR1.3 μm
10GbEUnit
GbE
Network CPU
SINET3
( Comm. & Cont.)
( Local Control)
CTLP( Cont. Port)
CHLP( Comm. POrt )
2.048 Gbps x 4 I/O ports 10GbE Port
Photo
10GbEUnit
From Kashima
FromKoganei11m
2GHz A/D
Real time Correlator
10 GbE Analyzer
Bit Rate Control in congestion
Bit RateDown to2Gbps
Bit RateDown to1Gbps
Bit RateDown to0.5Gbps
Time Code Not detected
Time Code Partially detected
Time Code completely detected.Possible to startcorrelation
Packet Arrival Time Records
No Congestion Under heavy congestion
Many packets are stockedin memory and suddenly released in very short time.
New function to pick up the suddenly released packetsare now considered.
Data Flow Monitoring
L1 on-demand connection
Efficient Use of limited Resource
• We can enjoy long time and wide bandwidth on Saturday and Sunday!
L1 on-demand connection
(1)Reservation (30minutes before observation)1) Request to the connection time2) Request to the bandwidth3) Negotiation for time and bandwidth4) Report for the time and bandwidth granted
(2)Telescope Operation(3)Real time Fringe Monitoring
First Success in real time observation on L1 on-demand connection
June 12,2008
Yamaguchi 32mTsukuba 32m
X-band2Gbps
Link Aggregation Technique
Binding cheap low-bit-rate links
And
Getting a extremely high bit rate
Link Aggregation of multiple GbEs
FoundryMLX-4
FoundryMLX-4
ADS-1000
BW=512MHz( 512-1024MHz)
VOA-200 SINET3A/D converterof 2.048-Gbpssampling
10GbEUnit Hope to carry 2Gbps
payload through threeGbE connections
ToMitaka, Tokyo
Hokkaido Universityin Sapporo
11m Telescopein Tomakomai
GbE x 3
Connections with low bit ratelinks in cheap cost
The link aggregation test will start in this summer.
Space Light Path
光空間伝送
Town, City
Observatory
Trunk CommunicationLine
Laser Beam Tracking Mirror developed10-Gbps, 10-km connection is a target.
Compact Opt TX/RX system
Conclusions
• Efficient Use of Communication Line– shared use of 10GbE line
• successfully demonstrated in the test between Kashima-Koganei
– L1 on-demand connection• successfully performed in the first test between Ymaguchi an
d Tsukuba
– Link Aggregation• to be achieved in 2008
– Space Light Path Connection• To be tested in Usuda 64m site