Changes between Version 12 and Version 13 of GENIEducation/SampleAssignments/CCNAssignment/ForInstructors


Ignore:
Timestamp:
06/04/13 16:03:49 (6 years ago)
Author:
shuang@bbn.com
Comment:

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  • GENIEducation/SampleAssignments/CCNAssignment/ForInstructors

    v12 v13  
    167167  Log into the host collaborator1 and use the Atmos client to fetch data from 1902/01/28 to 1902/02/03. Look at the GEMINI data usage, and observe that data is pulled from both datasource1 and datasource2, through router to researcher1 and ultimately to collaborator1. Record or remember the data rates and volumes from this transaction. On the GEMINI web interface (GENIDesktop), show real-time graphs from datasource1, datasource2, router, researcher1 and collaborator1, record the throughput numbers or screenshot the graphs. [[BR]]
    168168   [[Image(c1.png, 50%, nolink)]] [[BR]]
    169    As we can see here, collaborator1 first gets the data from 1902/01/28 to 1902/01/31 from datasource1 through router and researcher1; then gets the data from 1902/02/01 until 1902/02/03 from datasource2 through router and researcher1.
     169   As we can see here, collaborator1 first gets the data from datasource1 and datasource2 through router and researcher1.
    170170   - '''Question 1.3 A:''' [[BR]]
    171171   Log into ''collaborator2'' and fetch the same dates. Which hosts transfer data? why? [[BR]]
     
    555555   - '''Question 2.1 B''' [[BR]]
    556556   Which URI scheme is more efficient in time and network resources if the user only wants a few days of data? What if the user wants a full calendar month of data? [[BR]]
    557    '''Answer''': If the user only wants a few days of data, day-granularity is better: it consumes less network resources (bandwidth) and takes less time to fetch. If the user wants a full calendar month of data, it is better to use month-granularity since in this case, one request from the client side is enough, compared with around 30 (number of days in a month) consecutive requests from client side (which takes longer to query) if using day-granularity.
     557   '''Answer''': If the user only wants a few days of data, day-granularity is better: it consumes less network resources (bandwidth) and takes less time to fetch. If the user wants a full calendar month of data, it is better to use month-granularity since in this case, one request from the client side is enough, compared with around 30 (number of days in a month) consecutive requests from client side (which takes longer to query) if using day-granularity. [[BR]]
     558   Under month-granularity, it took about 20 seconds to get data for one day as well as one month (since the granularity is one month, user needs to at least get one month worth of data even if he/she only needs one day). Under one-day granularity, it took about 4.5 seconds to get 1 day of data and 130 seconds to get one month of data.
    558559
    559560 - '''3.3 Exploring the Impact of Caching''' -- Files to download: [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/cache.rspec cache.rspec]  [[BR]]