Weighing the Cloud

Page 55

Determining the ‘What’ To the left is a cybernetic model14 of TCP/IP protocol in the

Protocol version 4) data packets and then sent out across

context of sending or receiving a 50 KB photo. The TCP/

the Internet. The TCP/IP protocol checks if any packets are

IP protocol functions as a comparator - a component of

missing, request packets from the sending computer, and

a closed-loop system that compares information coming

notify the sender that the transmission is complete. This

from a sensor to the system goal. In the case of TCP/IP,

operation of error checking is called “cyclic redundancy

the protocol checks if a data transmission (divided into

checking” and used by networked devices when sending

packets) is complete and assembled in the right order.

and receiving transmissions.

Anything less, the protocol can request for parts of that

data to be transmitted again.

and take time (think of a landline phone call), is an ob-

Direct transmission of data, which can be inefficient

This model seeks to determine the ‘what’ of my thesis,

solete method of transmission for the Internet. However,

the content; it does not necessarily refer to the overall

due to the non-linear nature of the IP protocol, a Google

topic, but the actual category and detail of content so as

search request for example is not handled by one server,

to define the ‘why’, ‘how’, ‘who for’, ‘who by’, ‘where’, and

but by several, to give faster, more relevant results. There

‘when’. This exercise is not a linear process where defin-

is actually a carbon footprint estimated by Google for

ing ‘what’ first is necessary, rather to grasp exactly what

the average search request: about 0.2 grams of CO2.16

is being studied, however granular.

Along with the power a laptop consumes, Mike Berners-

On pursuing a thesis about the environmental effects

Lee estimates a Google search creates 0.7 grams of CO2.

of cloud-based computing, I need to better understand

Multiply that by the 200 to 500 million search requests

what I am measuring as well as the infrastructure (so I

per day, and Google searching actually accounts for 1.3

can determine ‘where’ and ‘when’ is the best point for

million tons of CO2 emissions per year.17

intervention). The ‘what’ in my case is data - little bits of 0’s and 1’s that live on your hard drive, and are subsequently stored and transmitted by remote server(s). The more data, the more energy consumed by the server.

Data is measured in bits and bytes (8-bits); you’ve

most likely seen the data on your computer in megabytes (MB) or gigabytes (GB). When you send any type of data over the Internet such as an email, photo, or gchat message, your data is divided up into packets. On average, the size of these packets are 576 bytes or 4,608 bits,15 and consist of a header and trailer, with the data in between. You may or may not know that your computer has an IP (Internet Protocol) address - a unique numerical identifier for every device on a network. Even websites have IP addresses. The header of each data packet would contain information on the origin or sending IP address, destination or receiving IP address, and total size of the packet. The trailer of each data packet would contain information on how many packets there are and in what order to reassemble them back into the original data.

If I were to send a friend a 50 KB photo, the photo

would be broken up into approximately 87 IPv4 (Internet 55


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