What's the differnce between surfing and downloading speed?

Question

I have spent quite a lot of time searching an answer for this question but haven't found an satisfactory answer.

My perception is that everything that you see in your browser is downloaded on your PC. The proof for this is: Let a webpage load in your browser and when its loading completes then select working offline or close your internet connection and save that page, which results in the saving of your webpage on your hard disk with the key to watch this page any number of time you want.

So, it shows that your page's been downloaded when you accessed it and the speed of accessing your webpage will surely then depend on your downloading speed, then where does this term "Surfing Speed" comes.

I may be wrong in my perception but I would love to know the correct answer to my query. Thanks. And yes I admit that my proof does not validate when the webpage is developed in languages like asp.

Answer 1

Well, when I think "download speed" I think about what it takes to transfer a file. Bit Torrent, FTP, anything. But "surfing speed" has a lot more going on than just moving a file. Even a single web page can be many files from many different locations. If an ISP is advertising that they have increased "surfing speed" then they're probably referring to optimizations they've made to the latter.

Maybe they've improved their DNS resolution (or in the case of AT&T for a while, they hijacked it and didn't improve anything...), maybe they have a more localized caching system for users so that commonly-fetched sites and content are rendered from cache and not re-fetched from the source, etc.

They tend not to internally cache, say, the latest ISO for your favorite Linux distro. But if you go to msn.com, chances are that someone else near you on your ISP has recently and the ISP already has that data, so they don't need to get it all from msn.com again. Each (of potentially hundreds per page) fetch can be made a little bit faster, and it adds up.

Answer 2

Not necessarily the same thing. Your actual speed of downloading data will be constrained by the bandwidth of your network connection, so suppose you can get X kB / second then that's how many actual bytes of data you can slurp.

Now think about the things that affect how that actually appears to you:

how fast does your broswer render a downloaded page?

• a webpage with a dodgy connection at the other end might not serve the page at the full rate that you could retrieve it at
• the raw data rate includes actual TCP?IP packets, a webpage that has to go through 7 redirects to actually be displayed to you (with a DNS look up and a new TCP connection and HTTP request each time) will appear much more slowly
• your ISP might offer compression, whereby you visit a webpage, the ISP compresses it at their end and then you run special decompression software at your end. So, fewer actual bytes of data to be transferred, but the compression / decompression time might outweigh that
• size of your ISP's proxy cache - and is the page you requested already in it or not

All of these things taken into account will give you your "surfing speed". It's really a slightly meaningless number given that it varies wildly depending on exactly what you are looking at.