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On January 31st, 2008, the NY Times, BBC, The Guardian, CNN and many others reported that one undersea cable was damaged near Alexandria, Egypt, and the other in the waters off Marseille, France. The two cables damaged Wednesday morning , which are separately managed and operated, were damaged within hours of each other. Operators believe the damage was caused by ship anchors during a heavy storm at sea. One of  the cables, Sea Me We 4,  is owned by 16 telecommunications companies along its route. The second cable, known as the Flag (for Fiber-optic Link Around the Globe) System, runs from Britain to Japan. The outages mainly affected the Middle East and Asia. Most disrupted communications were quickly rerouted through other cables. We decided to look at the impact on Internet connectivity as seen by the PingER project measurements.

Looking at the hourly ping losses (there are ~20 pings in an hour, so a loss of 1 ping is 5% loss) for January 30th 2008 for large increases in losses which persisted to the end of the day (to avoid regular diurnal change), the main effects seen were on:

Country

Loss before

Loss after

Sites affected / total

Sudan

< 4.5%

> 15%

3/3

Bahrein

0%

>10%

2/2

UAE

<4.5%

>20%

1/1

Jordan

0%

>15%

4/4

Oman

0%

>15%

1/1

Qatar

0%

>4.5%

1/1

Saudi Arabia

0%

>4.5%

2/3

India

0%

>50%

2/8

 

 

 

 

                  Table 1: Hourly Ping Losses
Since the effect may have been transitory while the data was re-routed we looked for increases in losses on January 30th.

Coiuntry

Loss before

Los after

Sites affected / total

Egypt

<1%

>7.5%

3/3

Sudan

<5%

>30%

3/3

Hong Kong

<0.75%

>11%

1/1

UAE

<4%

>18%

1/1

Bahrein

<1.5%

>7%

2/2

Jordan

<3%

>7%

3/4

Oman

<8%

>13%

1/1

Saudi Arabia

<1.2%

>7%

2/3

Syria

<3%

>7%

1/1

Indonesia

< 2%

>8

1/7

Thailand

<0.2%

>8%

1/6

Bangladesh

<5%

> 7%

2/2

India

<3%

> 40%

2/8

Sri Lanka

<3%

>6%

2/5

Maldives

<1%

>12%

1/3

                  Table 2: Daily Ping Losses
The diffrences between the dialy and hourly tables may refelect the sites/countries abilities to switch to alternate routes.

Looking further into data by PingER we can estimate start time for this event . The exact time is bit harder to explain but it is generally between 5 AM and 7 AM GMT on  January 30th 2008  for most of the countries in table 1 with the only exception of Bahrain where it all started at 9AM.  The difference might be  due to  sampling rate or monitoring hosts clock synchronization issue.

PingER calculates throughput of different nodes using Mathew's Formulae 

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