Transcript GISC network bandwidth requirements A proposed method for an educated guess… Hiroyuki Ichijo – JMA Rémy Giraud - ECMWF ET-CTS Co-Chairs Slide 1 ET-CTS - GISC.

GISC network bandwidth requirements
A proposed method for an educated guess…
Hiroyuki Ichijo – JMA
Rémy Giraud - ECMWF
ET-CTS Co-Chairs
Slide 1
ET-CTS - GISC Network Bandwidth Requirements
Slide 1
Introduction

As part of the requirements of the WIS, each GISC must:

host a Discovery, Access and Retrieval (DAR) catalogue

hold and distribute at least 24 hours of current WMO data and
products intended for global distribution.

Each GISC is responsible for coordinating with the Centres within its
area of responsibility a WIS telecommunications infrastructure that
can meet the WIS requirements for information exchange within the
area and that can exchange agreed WIS time critical and operational
critical information.

The WIS real-time network would be composed of a small number of
Area Meteorological Data Communication Networks (AMDCNs) and a
WIS core network interconnecting the GISCs and AMDCNs together.
GISCs would be responsible for ensuring that their AMDCNs are
developed and maintained and, where the appropriate agreements
are in place, the traffic between WIS centres in different AMDCNs is
managed. [extract from CBS-XIV Abridged Slide
final2 report ]
ET-CTS - GISC Network Bandwidth Requirements
Slide 2
Background for consideration (1)

The Improved MTN (IMTN) project started at ET-IMTN meeting in
Sep/Oct 1999. Its implementation has progressed in technical
evolution process as the configuration of two clouds (i.e. Network I &
Network II) until Sep 2009. By the end of 2009, all links via Network I
have migrated to via Network II. Currently the IMTN is operating on a
single coordinated MPLS cloud.

Since a WIS core network will be established on the IMTN, it is easy to
realize the full-mesh GISC topology. However it is expected that traffic
on the WIS core network handled by GISCs will considerably increase.
To support future-oriented WIS operation, network capacity of each
GISC will have to be expanded in collaboration with others.
Main task
Required GISC bandwidth on the core network should be considered
carefully considering not only bulk but also peak traffic. In addition, it is
important to study smooth evolution process in gradual participation of
Slide 3
operational GISCs.
ET-CTS - GISC Network Bandwidth Requirements
Slide 3
Background for consideration (2)

Appropriate maximum number of GISCs has come up for discussion
repeatedly since the initial stage called as FWIS:
[Extraction from the final report of CBS-ext.02, Annex IV]
Several (perhaps four to 10) centres would serve as GISCs. Each GISC
would have a defined area of responsibility. GISCs would usually be located
within or closely associated with a centre running a global data assimilation
system or having some other global commitment, such as a WMC.
[Extraction from ET-CTS outcome reported to ICG-WIS-3 in 2006]
Correlation between the number of GISCs and reasonableness of full-mesh
topology of a WIS core network:
From the practical and relative evaluation, the full-mesh can be appropriate
on the assumption that the number of GISCs would be less than 7
inclusive. In case of more GISCs, the full-mesh should be avoided.

However 13 GISCs candidates have been identified as of the end of
November 2009.
Sense of a possible basis
Further study is desired to clarify the appropriate
Slide 4 maximum number of
GISCs from the practical view of network bandwidth requirements.
ET-CTS - GISC Network Bandwidth Requirements
Slide 4
Hypothesis (1)
 Flows

Each GISC will receive data from its area of responsibility on an
AMDCN

A backup GISC should be available to receive data from Centres
from another AMDCN

All GISCs will be linked directly each other (i.e. mesh-topology)

Each GISC will push all data received to all other GISCs

Not all AMDCN will provide the same amount of data. (i.e.
unbalanced model)
Slide 5
ET-CTS - GISC Network Bandwidth Requirements
Slide 5
Hypothesis (2)
 Technical

A WIS core network to link all GISCs will not be based on multicast but uni-cast mechanism for, at least, initial implementation

All network protocol have an overhead. A 20% overhead is a
typical value for FTP

Despite control, there will be duplicated data over the network.

In order to define the bandwidth requirements, it will be
necessary to estimate:
 Daily data volume to be sent and received
 Estimate of peak rates if the data transfers are not evenly
spread over the 24 hours.
Slide 6
ET-CTS - GISC Network Bandwidth Requirements
Slide 6
Points to study (1)

The required bandwidth for each GISC will depend on:
 The total number of GISCs
 The estimated amount of data to be transferred daily by each GISC
 The potential peaks of traffic within the 24 hours period
 The traffic repartition between AMDCN:
 An unbalanced traffic pattern between the GISCs will have a lot of
impact
 The protocols used on the network and their overhead
Thus we should:
i) estimate data volume for global exchange more practically;
ii) develop a matrix sheet to indicate bandwidth requirements in each case;
Slide of
7 GISCs if possible.
iii) recommend an appropriate maximum number
ET-CTS - GISC Network Bandwidth Requirements
Slide 7
Points to study (2)

An online spreadsheet available at
http://spreadsheets.google.com/ccc?key=0AsDEZG6XKnasdG9MNWlRYXUzeVJJRkJsWFppWlI0UEE&hl=fr
Is a tool to be used to automate some calculation for the bandwidth. Based
on values to be defined online by the user, it is then possible to estimate
the required bandwidth.

To access this document a freely available Google account is required

Please use Sheet “Comments and History” to add comments and
suggestions to improve the spreadsheet.
Slide 8
ET-CTS - GISC Network Bandwidth Requirements
Slide 8
References and hints
Slide 9
Network I
Tokyo
Melbourne
Washington
Buenos Aires
Brasilia
Beijing
Sofia
Prague
Moscow
New Delhi
Exeter
Jeddah
Network II
IMTN evolution
Offenbach
Nairobi
Toulouse
Dakar
Cairo
New Delhi
Algiers
Moscow
Jeddah
RA II
Beijing
Tokyo
Sofia
RA VI
Prague
Washington
Exeter
IMTN cloud
Offenbach
RA IV
Toulouse
Brasilia
Buenos Aires
RA III
Cairo
Slide
10
Dakar
Nairobi
ET-CTS - GISC Network Bandwidth Requirements
Algiers
Melbourne
RA V
RA I
Slide 10
Full-mesh topology of WIS core network
 Full-mesh topology will bring two benefits:
(1) maximum redundancy in the configuration of GISC backup channels;
(2) operational simplicity in data synchronization
Conceptual interrelation between GTS and WIS networks
WIS multicast network
IGDDS,etc
AMDCN
AMDCN
Internet
DAR
Max 18 centers
AMDCN
IMTN
GTS
More than 180
centers
AMDCN
WIS core
network
Slide 11
ET-CTS - GISC Network Bandwidth Requirements
Less than 13
centers
Slide 11
Priorities of study for bandwidth requirements
IGDDS,etc
Internet
DAR
AMDCN
AMDCN
Third priority
WIS core
network
GISC
Second priority
First priority
Target in this period
Slide 12
ET-CTS - GISC Network Bandwidth Requirements
Slide 12
Architecture and flows
Slide 13
ET-CTS - GISC Network Bandwidth Requirements
Slide 13
Balanced model (4 GISCs case)
2GB
Responsible area #1
2GB
AMDCN #1
Responsible area #2
AMDCN #2
Example case of total volume of 8GB
Incoming
GISC #1
2GB
2GB
2GB
2GB
Necessary
GISC #2
2GB
Outgoing
daily
daily
volume
volume
port speed
2GB
Bandwidth
WIS core network
(Full-meshed topology)
GISC
#1
6 GB
6 GB
appropriate
for
GISC #3
GISC
#2
AMDCN #3
2GB
6GB/day
GISC #4
AMDCN #4
Responsible area #3
2GB
ditto
ditto
ditto
GISC
ditto
#3 14
Slide
ditto
ditto
ditto
ditto
GISC
Responsible area #4 #4
ET-CTS - GISC Network Bandwidth Requirements
ditto
Slide 14
Unbalanced model (4 GISCs case)
5GB
Responsible area #1
1GB Responsible area #2
AMDCN #1
Example case of total volume of 8GB
AMDCN #2
Incoming
GISC #1
Outgoing
Necessary
GISC #2
1GB
1GB 1GB
5GB
5GB
5GB
1GB
1GB
1GB
WIS core network
1GB
daily
daily
5GB
volume
volume
port speed
1GB
Bandwidth
(Full-meshed topology)
GISC
#1
3 GB
15 GB
appropriate
for
GISC #3
GISC #4
15GB/day
AMDCN #3
1GB
AMDCN #4
Responsible area #3
1GB Responsible area #4
Bandwidth
GISC
Slide
15 7 GB
#2
3 GB
appropriate
for
7GB/day
ET-CTS - GISC Network Bandwidth RequirementsGISC
#3
Slide 15
ditto
ditto
ditto
Reference to volume required (1)
Average daily volume received at RTH Washington: 26.66 GB
(as of May 2008)
Volume received by Protocol
Slide 16
ET-CTS - GISC Network Bandwidth Requirements
Slide 16
Reference to volume required (2)
Average daily volume transmitted from RTH Washington: 30.81 GB
(as of May 2008)
Volume transmitted by Protocol
Slide 17
ET-CTS - GISC Network Bandwidth Requirements
Slide 17
Reference to volume required (3)
Results of RTH data survey 1 August 2007
Incoming
(including duplicated ones)
GTS
Outgoing
(after duplicated check and
elimination)
Download volume
Internet
Upload volume
Other
connections
Incoming
Outgoing
Daily volume (messages)
Daily volume (files)
Total daily volume (GB)
Daily number of messages
Daily number of files
Daily volume (messages)
Daily volume (files)
Total daily volume (GB)
Daily number of messages
Daily number of files
Total daily incoming traffic (GB)
Daily obtaining volume on operational basis
Total daily outgoing traffic (GB)
Daily providing volume on operational basis
Total daily volume (GB)
Total daily volume (GB)
RTH-A
RTH-B
855 MB
986 MB
1.8
202,200
425
545 MB
571 MB
1
292500
526
146
1.8 GB
137
2.3 GB
0.2
0.1
2 GB
0.55 GB
2.6
289,784
567
2.4 GB
1.6 GB
4
855,318
951
2.6
13 MB
13.9
1.1 GB
24.8
62.5
12%
Growth Rate Per Annum in volumes
RTH-C
RTH-D
Average
Max
4.52
369,065
1,540
2.92
397,021
30,727
2.96
314517.5
8314.75
1.8
202200
425
4.52
397021
30727
0.753
238,747
539
41.57
6.89
1,135,909
47,098
8.47
3.18575
630618.5
12278.5
49.66
0.753
238747
526
2.6
6.89
1135909
47098
146
148.43
19.18
79.6275
13.9
148.43
8.1
8.3
32-50%
0.01
0.3
35-50%
8.3
17.8
0.01
0.1
24.8
62.5
Slide 18
Extract from ICG-WIS IV (31.VIII.2007) /Doc. 3.1(1)
http://www.wmo.int/pages/prog/www/ISS/Meetings/ICG-WIS_ECMWF2007/documents/RRR-Doc3-1-1.doc
ET-CTS - GISC Network Bandwidth Requirements
Min
Slide 18
Reference to volume required (4)
Past and projected data volumes (RTH-C)
Slide 19
Extract from ICG-WIS IV (31.VIII.2007) /Doc. 3.1(1)
http://www.wmo.int/pages/prog/www/ISS/Meetings/ICG-WIS_ECMWF2007/documents/RRR-Doc3-1-1.doc
ET-CTS - GISC Network Bandwidth Requirements
Slide 19