Posted by Benjamin Niemann on 09/06/05 23:35

osfwofujro wrote:

> When I connect to a webpage the page downloads on to my computer. When
> the page has finished downloading, am I correct in thinking that the
> connection between me and the web server terminates?

Not necessarily. HTTP/1.1 knows 'keep-alive': if both sides (client and
server, and perhaps proxies inbetween) support it, the connection will be
kept open and be reused for more request. This can significantly improve
page loading times (e.g. with lots of graphics), because the TCP handshake
to initiate a connection does not have to be performed for every
document/media object.

> And then if I click on another link in the same site or refresh the
> page, then I reconnect from scratch again?

Only if your at least one of the parties involved (client, server, proxies)
does not support keep-alive or all connection have been closed after a
certain timeout.

> And that the webpage knows
> who I am (say if it's webmail) because of the cookie?

That is just one of several possibilities. Others are session IDs in the
query part of the URL (...?SID=3487387...), the referer header, your IP
address or the ETag header could be abused for this. The latter three are
all too fragile to be used e.g. for session management as it's used for a
webmail application. Cookies or query strings are commonly used for this.

> IOW, once the page has downloaded, the link between me and the website
> is over - until I request another page/graphic/text on that site?

see above

--
Benjamin Niemann
Email: pink at odahoda dot de
WWW: http://www.odahoda.de/

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