Internet performance is improving each year with througputs typically improving by 40-50% per year and losses by 25%-45% per year, and for some regions such as S. E. Europe, even more. Geosynchronous satellite connections are still important to countries with poor telecommunications infrastructure and for outlying areas. However, the number of countries with fiber connectivity has and continues to increase and in most cases, satellite links are used as backup or redundant links. In general for HEP countries satellite links are being replaced with land-line links with improved performance (in particular for RTT). On the other side of the coin Internet usage is increasing (see http://www.internetworldstats.com/stats.htm), the application demands (see for example [bcr]) are growing and the expected reliability is increasing, so we cannot be complacent.

In general, throughput measured from within a region is much higher than when measured from outside. Links between the more developed regions including N. America[1], Japan and Europe are much better than elsewhere (3 - 10 times more throughput achievable). Regions such as Russia, S.E. Asia, S.E. Europe and Latin America are 3-6 years behind. Russia and S.E. Asia are catching up slowly. However, Africa, S. Asia and C. Asia are 8-10 years behind and even worse appear to be falling further behind. Looking forward ten years to 2016, if the current rates of progress continue, then performance from N. America to Africa will be 1000 time worse than to Europe, to S. Asia and C. Asia will be 100 times worse than to Europe.

Africa and South Asia are two regions where the internet has seen phenomenal growth, especially in terms of usage. However, it appears that network capacity is not keeping up with demand in these regions. In fact many sites in Africa and India appear to have throughputs less that that of a well connected (cable, DSL or ISDN) home in Europe or Anglo America. Further the end-to-end networking is often very fragile both due to last mile effects and poor infrastructure (e.g. power) at the end sites, and also due to lack of adequate network backup routes. Africa is a big target of opportunity with 915 million people and a 625% growth in number of Internet users from 2000-2006. However, there are many challenges including lack of power, import duties, lack of skills, disease and protectionist policies. In almost all measurements Africa stands out as having the poorest performance and even worse is falling behind much faster than any other region. Further Africa is a vast region and there are great differences in performance between different countries and regions within Africa.

There is a strong positive correlation between the Internet performance metrics and various economic and development indices available from the UN and ITU. Besides being useful in their own right these correlations are an excellent way to illustrate anomalies and for pointing out measurement/analysis problems. The large variations between sites within a given country illustrate the need for careful checking of the results and the need for multiple sites/country to identify anomalies. Also given the difficulty of developing the human and technical indicators (at best they are updated once a year and usually much less frequently), having indicators such as PingER that are constantly and automatically updated is a useful complement.

For modern HEP collaborations and Grids there is an increasing need for high-performance monitoring to set expectations, provide planning and trouble-shooting information, and to provide steering for applications.

To quantify and help bridge the Digital Divide, enable world-wide collaborations, and reach-out to scientists world-wide, it is imperative to continue and extend the PingER monitoring coverage to all countries with HEP programs and significant scientific enterprises.

Introduction

This report may be regarded as a follow on to the May 1998 Report of the ICFA-NTF Monitoring Working Group [icfa-98], the January 2003 Report of the ICFA-SCIC Monitoring Working Group [icfa-03], the January 2004 Report of the ICFA-SCIC Monitoring Working Group [icfa-04], the January 2005 Report of the ICFA-SCIC Monitoring Working Group [icfa-05] and the the January 2006 Report of the ICFA-SCIC Monitoring Working Group [icfa-06].

The current report updates the January 2006 report, but is complete in its own right in that it includes the tutorial information from the previous reports. The main changes in this year’s reports are:

· Figures 1-6, 8-10 and 13 and Tables 1, 2, 4 and 6 have all been updated

· The text related to all the above tables and figures has been updated.

· Sections have been added on:

o A Case Study for Africa

o LHC-OPN Monitoring

o Related HEP research

o Tools to manage, analyze and visualize the PingER data

§ PingER Host search tool

§ PingER Executive plots

§ ViPER visualization

§ PingER data validation and management

§ Tools to validate the PingER data

· Figures 22-25 are new.

· We have updated the section on PingER publications and talks.

ICFA/SCIC Network Monitoring Working Group

The formation of this working group was requested at the ICFA/SCIC meeting at CERN in March 2002 [icfa-mar02]. The mission is to: Provide a quantitative/technical view of inter-regional network performance to enable understanding the current situation and making recommendations for improved inter-regional connectivity.

The lead person for the monitoring working group was identified as Les Cottrell. The lead person was requested to gather a team of people to assist in preparing the report and to prepare the current ICFA report for the end of 2002. The team membership consists of:

Table 1: Members of the ICFA/SCIC Network Monitoring team

Les Cottrell	SLAC	US	cottrell@slac.stanford.edu
Richard Hughes-Jones	University of Manchester	UK	rich@a3.ph.man.ac.uk
Sergei Berezhnev	RUHEP, Moscow State.Univ.	Russia	sfb@radio-msu.net
Sergio F. Novaes	FNAL	S. America	novaes@fnal.gov
Fukuko Yuasa	KEK	Japan and E. Asia	Fukuko.Yuasa@kek.jp
Shawn McKee	Michigan	I2 HEP Net Mon WG	smckee@umich.edu

Goals of the Working Group

· Obtain as uniform picture as possible of the present performance of the connectivity used by the ICFA community

· Prepare reports on the performance of HEP connectivity, including, where possible, the identification of any key bottlenecks or problem areas.

Methodology

There are two complementary types of Internet monitoring reported on in this report.

1. In the first we use PingER [pinger] which uses the ubiquitous "ping" utility available standard on most modern hosts. Details of the PingER methodology can be found in the May 1998 Report of the ICFA-NTF Monitoring Working Group [icfa-98] and [ejds-pinger]. PingER provides low intrusiveness (~ 100bits/s per host pair monitored[2]) Round Trip Time (RTT), loss, reachability (if a host does not respond to a set of 21 pings it is presumed to be non-reachable). The low intrusiveness enables the method to be very effective for measuring regions and hosts with poor connectivity. Since the ping server is pre-installed on all remote hosts of interest, minimal support is needed for the remote host (no software to install, no account needed etc.)

2. The second method (IEPM-BW [iepm], perfSONAR [perfSONAR] etc.) is for measuring high network and application throughput between hosts with excellent connections. Examples of such hosts are to be found at HEP accelerator sites and tier 1 and 2 sites, major Grid sites, and major academic and research sites in N. America², Japan and Europe. The method can be quite intrusive (for each remote host being monitored from a monitoring host, it can utilize hundreds of Mbits/s for ten seconds to a minute each hour). It also requires more support from the remote host. In particular either various services must be installed and run by the local administrator or an account is required, software (servers) must be installed, disk space, compute cycles etc. are consumed, and there are security issues. The method provides expectations of throughput achievable at the network and application levels, as well as information on how to achieve it, and trouble-shooting information.

PingER Results

Deployment

The PingER data and results extend back to the start of 1995. They thus provide a valuable history of Internet performance. PingER has over 30 monitoring nodes in 14 countries, that monitor over 700 remote nodes at over 600 sites in around 120 countries (see PingER Deployment [pinger-deploy]). These countries contain over 89% of the world's population (see Table 2) and over 99% of the online users of the Internet. Most of the hosts monitored are at educational or research sites. We try and get at least 2 hosts per country to help identify and avoid anomalies at a single host, although we are making efforts to increase the number of monitoring hosts to as many as we can. The requirements for the remote host can be found in [host-req]. Fig. 1 below shows the locations of the monitoring and remote (monitored sites).

Figure 1: Locations of PingER monitoring and remote sites as of Jan 2007.

There are over two thousand monitoring/monitored-remote-host pairs, so it is important to provide aggregation of data by hosts from a variety of "affinity groups". PingER provides aggregation by affinity groups such as HEP experiment collaborator sites, Top Level Domain (TLD), Internet Service Provider (ISP), or by world region etc. The world regions, as defined for PingER, and countries monitored are shown below in Fig. 2. The regions are chosen starting from the U.N. definitions [un]. We modify the region definitions to take into account which countries have HEP interests and to try and ensure the countries in a region have similar performance.

Figure 2: Major regions of the world for PingER aggregation by regions

More details on the regions are provided in Table 2 that highlights the number of countries monitored in each of these regions, and the distribution of population in these regions.

Table 2: PingER Monitored Countries and populations by region Jul-Dec 2006

Regions	# of Countries	% of World Population
Africa	32	12
Central Asia	9	2