network.http.keep-alive
(Boolean).
Setting this to trueenables the use of
persistent connections. This can provide more efficient
connections with legacy servers as it streamlines the
process, e.g. fewer TCP connections/packets and pipelining
support. In the event of problems arising with legacy
servers set this to false. HTTP/1.1 supports
persistent connections by default.
network.http.max-persistent-connections-per-server
(Integer).
The
value entered here determines that maximum number of
persistent connections to a server, with valid values being
1 – 255, the default being 2 as
recommended in the HTTP/1.1 specification.
network.http.proxy.keep-alive
(Boolean).
Setting this to trueenables the use of
persistent connections over proxy servers. This can provide
more efficient connections with legacy servers as it
streamlines the process, e.g. fewer TCP connections/packets
and pipelining support. In the event of problems arising
with legacy servers set this to false. HTTP/1.1
supports persistent connections by default.
network.http.max-persistent-connections-per-proxy
(Integer).
The
value entered here determines that maximum number of
persistent connections to a proxy server, with valid values
being 1 – 255, the default being 4
as recommended in the HTTP/1.1 specification.
network.http.pipelining
(Boolean).
HTTP/1.1 pipelining is a feature that allows multiple HTTP
requests to be issued simultaneously. Without pipelining,
HTTP requests are issued sequentially, with each further
request not being issued until the previous has been
completed. While this may seem like a more optimal approach,
it’s not without its
detractors (Check out the Comments in particular).
Firefox also contains an internal listing of servers that
don’t support pipelining and disables it for those to
avoid problems (This isn’t necessarily definitive of
course). As such, you might find some experimentation
worthwhile with this feature rather than just assuming it’s
always beneficial (As others guides seem to believe). As
stated on W3C’s
Network Performance Effects of HTTP/1.1, CSS1, and PNG;
HTTP/1.1
implemented with pipelining outperformed HTTP/1.0, even when
the HTTP/1.0 implementation uses multiple connections in
parallel, under all circumstances tested. In terms of
packets transmitted, the savings are typically at least a
factor of 2, and often much more, for our tests. Elapsed
time improvement is less dramatic, but significant.
Set this to
true to enable pipelining (recommended), false
to disable. Further information can be found at
Mozilla.org’s Pipelining FAQ.
network.http.proxy.pipelining
(Boolean).
This feature performs exactly as per the above (true
to enable, false to disable), albeit it
applies to connections over a proxy. As before, this is a
feature you may want to experiment with to determine its
benefits, if any.
network.http.pipelining.maxrequests
(Integer).
This
specifies the maximum number of requests in a
pipeline, the default being 4. If you have set
both network.http.pipelining and
network.http.proxy.pipelining to false this
option can be ignored. The
Pipelining FAQ makes the following point on the matter,
pipelining many requests can be costly if the connection
closes prematurely because we would have wasted time writing
requests to the network, only to have to repeat them on a
new connection. Moreover, a longer pipeline can actually
cause user-perceived delays if earlier requests take a long
time to complete. So while in general it would make
sense to set a higher value (With the limit being
8), it may also be something you should experiment with
to determine an optimal value.
network.http.max-connections
(Integer).
The
value entered here specifies the maximum number of
HTTP connections Firefox can make simultaneously, the
default being 24, with valid values being 1
– 65535. On high bandwidth connections increasing
this value can prove effective in reducing the amount of
time required to download multiple pages, e.g. If you open
multiple tabs at once/in short succession, as it allows
Firefox to create more connections. That said, setting this
too high can have adverse affects also (Assuming you
actually were in a scenario where a large amount of
connections were attempted). As such, a decent maximum
value for broadband users would be 48.
network.http.max-connections-per-server
(Integer).
The
value entered here specifies the maximum number of
simultaneous connections to a server, the default
being 8, with valid values being 1 – 255.
Increasing this value can improve the loading times
of certain sites (Or if multiple pages of a site are loaded
simultaneously) as more data can be fetched at once. This is
of most potential benefit to those with broadband
connections, who will have the bandwidth to take advantage
of this. Similar to the previous option, a decent maximum
to set this to would be double the default, i.e.
16. Bear in mind however that the more connections you
are tying up, the less that will be available to others
wishing to connect to the same server – so don’t set this
excessively high just because you can.
network.prefetch-next
(Boolean).
Mozilla provides support
for a “neat” feature called Link Prefetching, a browser
mechanism, which utilizes browser idle time to download or
prefetch documents that the user might visit in the
near future. This is (understandably) a
cause of concern
for many, who aren’t happy with their browser downloading
content from sites which they may not even view anyway.
Despite what you may have read elsewhere, there’s no need to
get too hysterical about this. The most notable site
which uses it currently is
Google and where
it does (as not all searches do) it only uses it for the top
search result, e.g. searching for Firefox yielded
Firefox - Rediscover the web
as the top result, and that’s only 1 to use the
rel=”prefetch” tag for prefetching. Of perhaps more
concern is that prefetching occurs during
Firefox
idle time, e.g. you could have an Internet
Explorer download active, but if Firefox is idle, it will
still initiate prefetching. Further details are available
Mozilla.org’s Link
Prefetching FAQ. Set this to true to
enable link prefetching for potentially faster loading
times of prefetched sites, while if you are more
privacy/security conscious set this to false instead
to ensure only content for sites you intended to view is
ever downloaded.
network.http.redirection-limit(Integer).
The value entered here
specifies the maximum number of redirects that can be
attempted consecutively, e.g. after replying in a forum you
may be redirected to your response. As noted in
Bug 153888 the
default valuehas been increased from 10 to
20 (on account of nytimes.com). While you may prefer
to decrease this value to avoid exploitation by
certain sites, it may be necessary to increase the
value in order for some to work (If this is the case an
error page stating Redirection limit for this URL exceeded
will appear).
network.http.sendRefererHeader
(Integer). The value entered here controls the
transmission of the Referer HTTP header. This Referer header
states the URL from which the browser was referred, e.g. if
you click a link in this guide to another website, then
techspot.com would be stated as the referrer, etc. This can
be useful for sites as they can determine where traffic
generates from, e.g. Google. Where no URL exists as the
referral source, e.g. typing in the address, none is sent.
Three options are available.
0. This
disables the sending of the Referer header, which yields
a minimal bandwidth saving. This is perhaps more so useful
if you are privacy conscious and simply don’t want it to be
known where you were linked from.
1. This
specifies that the Referer header is only sent for clicked
hyperlinks.
2. This
specifies that the Referer header is sent for clicked
hyperlinks and images.
network.http.sendSecureXSiteReferrer
(Boolean). This setting controls the transmission of
the Referer HTTP header between secure sites. It’d be
recommended to set this to true as many secure sites
will not function without the Referer header present, as
part of a security check (As discussed in
Bug 141641), e.g.
some sites use a third party company for processing credit
card transactions and may fail without the header. It
shouldn’t be necessary to set this to false.
Plugins
flashblock.blockLocal (String).
Available when the
Flashblock
extension is installed, this allows you to set how
Flashblock interacts with local Flash content. By default
this is set to false, which results in Flashblock not
attempting to block any local Flash content in Firefox. When
set to true local Flash content is filtered similar
to non-local content, i.e. replaced with a button before
being initiated.
plugin.expose_full_path (Boolean).
Typing about:plugins into Firefox’s Address bar and
hitting Enter displays a listing of plugins installed. With
this set to true the complete path to the plugin is
displayed, e.g. File name: C:\Program Files\Mozilla
Firefox\plugins\npnul32.dll. This may be of some use as not
all plugins are located in the Firefox\plugins directory.
When set to false only the plugin names are
displayed, e.g. File name: npnul32.dll.
security.enable_java
(Boolean).
Setting this option to
trueenables support for Sun MicroSystem’s
Java
in Firefox. If you haven’t got this installed then obviously
you may leave this set to false, or if you merely do
not want any Java content loaded on web pages, e.g. news
tickers. Personally I’d recommend downloading the Sun’s Java
VM and enabling this feature (this can also be used
to provide Internet Explorer with a much better Java VM
too). This is the same as the Enable Java option in
the Content tab.
plugin.default_plugin_disabled
(Boolean). Setting this to trueenables
Firefox to prompt you whenever you need a plugin not already
installed to view content on a page.
You can choose to
ignore this prompt, or install the required plugin. Set this
to false to disable such prompts.
plugin.scan.Acrobat (Also
Quicktime, SunJRE and WindowsMediaPlayer)
(String). These options are only relevant if you have
multiple versions of any of the 4 aforementioned
applications installed. It allows you to specify the
minimum version plug-in to scan for, e.g. if you have
QuickTime 5 and 7 installed and which to use the QuickTime 7
plug-in(s) only, change the value from 5.0 (default)
to 6.0. Again, this is not something most users will
need to, or should, alter. The default values are
Acrobat 5.0, QuickTime 5.0, SunJRE 1.3
and WindowsMediaPlayer 7.0.
privacy.popups.disable_from_plugins
(Integer). This option allows you to control how
popups from installed plugins are treated, three options are
available.
0. This
setting enables all popups from plugins, which isn’t
particularly recommended.
1. This
setting enables popups from plugins, up to the
limited specified by dom.popup_maximum (Covered
later).
2. This
setting disables creation of popups from plugins,
unless the site is listed as an Allowed Site in the
Content tab.
