SATA in comparison to other buses (sourced from wiki):

Name	Raw bandwidth (Mbit/s)	Transfer speed (MB/s)	Max. cable length (m)	Power provided	Devices per Channel
eSATA	3,000	300	2 with eSATA HBA (1 with passive adapter)	No[29]	1 (15 with port multiplier)
SATA 300	3,000	300	1	No	1 (15 with port multiplier)
SATA 150	1,500	150	1	No	1 per line
PATA 133	1,064	133	0.46 (18 in)	No	2
SAS 300	3,000	300	8	No	1 (16k with expanders)
SAS 150	1,500	150	8	No	1 (16k with expanders)
FireWire 3200	3,144	393	100; alternate cables available for >100 m	15 W, 12–25 V	63 (with hub)
FireWire 800	786	98.25	100[30]	15 W, 12–25 V	63 (with hub)
FireWire 400	393	49.13	4.5[30][31]	15 W, 12–25 V	63 (with hub)
USB 3.0*	4,800	600	3[32]	4.5 W, 5 V	127 (with hub)[32]
USB 2.0	480	60	5[33]	2.5 W, 5 V	127 (with hub)
USB 1.0	12	1.5	3	Yes
Ultra-320 SCSI	2,560	320	12	No	15 (plus the HBA)
Fibre Channel over optic fiber	10,520	2,000	2–50,000	No	126 (16,777,216 with switches)
Fibre Channel over copper cable	4,000	400	12	No	126 (16,777,216 with switches)
InfiniBand 12× Quad-rate	120,000	12,000	5 (copper)[34][35] <10,000 (fiber)	No	1 with point to point Many with switched fabric

Obviously, according to the chart, the transfer rate of SATA has go beyond the capability of the network since the introduction of SATA I. This fact makes the use of SATA II (not to mention SATA III) hard drive on a networked file server moo point if most of the usage of those disks are for sharing over the network.

or am I missing anything?

• Exposure is automatic but your Exposure Compensation controls still work.  This is Big. Using Exposure Compensation, you can influence the camera’s opinion on exposure within a range of four stops, over and under inclusive.
• Exposure Lock is available and must be used.  Once you and the camera agree on an exposure using the above-mentioned Exposure Compensation dial, lock that sucker down.  The last thing you want is for the camera to drastically change exposure just because something bright or dark suddenly enters frame.  Trust me it absolutely will if you don’t use the Exposure Lock feature.
• There are a couple of ways to do an autofocus approach but they are awkward and frustrating.  Buck up and learn to manually focus the way the big kids do.
• Sound can and will be recorded through an internal mic but don’t expect much quality.  The camera’s onboard mic will hear you best of all.  It will also hear the Image Stabilizer and any other camera noises.  Better sound can be acquired by using an external microphone that can be attached through the “audio in” plug.  Consider something like the Sennheiser MKE400 if sound is important and you don’t mind coughing up the cake.  I think it’s best to concentrate on picture during your earliest explorations…
• Yes! Image Stabilization does work in video mode and is always activated unless you manually turn it off on the lens.  This is a great help for handheld work and makes the 24-105mm f4 IS a really useful lens on the 5D Mark II.
• Still captures may be in RAW or jpeg format and either sRGB or Adobe RGB according to you choice.  The video color space is sRGB and no Raw equivalent is available.  Too bad; I hope this becomes available in future generations.  As it is, watch your exposures and stay tuned to proper white balance.
• Picture Styles apply!  This is also Big.  By custom tuning your Picture Styles, you can have great control over how the camera records color sharpness, and contrast.  B&W and Sepia modes are readily available and that just too cool for words…

Once it’s installed, the new firmware makes it pretty easy to actually perform your exposure adjustments. The same dials and controls you’d use to manually adjust exposure when taking still images are used during video recording, so operation is pretty intuitive for anyone with familiarity with the camera.

Make sure your Live View Function Setting is on Stills + Movie, and your Screen Settings are on Movie Display

Here’s the procedure:

1. Live View/Movie function settings: Be sure your LV (Live View) settings are set to “Stills + Movie”. Then, press the SET button as indicated on the Menu screen to drill one more step down, and set your Screen Settings to “Movie Display”.
   
   This last point is vital: If your Screen Settings are anywhere but “Movie Display” you will not be able to manually adjust exposure.


2. Turn the Mode Dial on top of the camera to “M” (Manual exposure mode), as you would to manually adjust exposure during a still image.


3. Press the Live View button (to the left of the viewfinder) to activate Live View. This is always a requirement before movie shooting is possible, and this firmware update doesn’t change that.



Press the INFO button on the rear of the camera to see the analog metering scale as an exposure reference in Movie Mode
4. If you want to see the camera’s analog metering scale to use as a guide for setting manual exposure, press the INFO button until it appears at the bottom of the LCD monitor. Now, as you make exposure adjustments, you’ll see the indicator on the scale change as lighting and settings change. Of course, users are also free to use a separate hand-held meter or other methods to determine proper shutter speeds, apertures, and ISO settings.


5. Turn the Main Dial (near the shutter button) to adjust shutter speeds, over a range of 1/30th thru 1/4000th of a second. Turn the rear Quick Control Dial to adjust the aperture setting, through the entire range available on the lens you’re currently using. And press the ISO button (top of camera) and turn the Main Dial to vary ISO, or set Automatic ISO operation.

As noted above, users can set manual shutter speeds during video recording anywhere from 1/30th of a second thru 1/4000th. Speeds can be set in 1/3-step increments, or via Custom Function I-1-1, in 1/2-step increments. Shutter speeds are set by turning the Main Dial, preferably before video recording begins, although they can be set and changed during actual recording.

Use the Main Dial to control the shutter speed during manual exposure in Movie Mode

The effects will take place virtually immediately, but it’s possible that the sound of clicking through the dial’s settings will be picked-up in your video footage through the camera's built-in micorphone (of course, that can be avoided by using an optional external microphone plugged into the camera's audio input, or using a seperate portable sound recording device).

Apertures are adjusted by simply turning the rear Quick Control Dial, once the EOS 5D Mark II has been set-up for Manual exposure shooting during video recording. Be sure the camera’s main On-Off switch is raised to its upper-most position, which activates the Quick Control Dial — if you’re just set to “ON”,

Use the Quick Control Dial to control the aperture settings during manual exposure in Movie Mode

the camera itself is active and turned on, but you won’t be able to adjust the Quick Control Dial for any exposure-based settings.

You can manually select any ISO from 100 - 6,400 (12,800/"H1" if the ISO Expansion Custom Function is active). To change the ISO, press the ISO button on top of the camera, and use the Main Dial to select the sensitivity you want

• Slow web browsing

• Websites timing out

• MSN Messenger disconnects

• Not able to connect to a bittorrent tracker

• Connection generally behaving strange

If you get the above symptoms when your p2p application is running then chances are that this tweak will fix these problems.

The only problem is that once you reboot your

router

for any reason, you will lose the tweaked settings, but not to worry, there is a quick way to re-apply the tweak with a few clicks. In order to make it easier to apply the tweak, you need to follow this simple guide below.

Let's get busy

First, download

Telnet Scripting Tool (TS10) by Albert Yale

. Extract it to a safe place and in that same folder make a text file called 'p2ptweak.txt'.

Paste the following script into that 'p2ptweak.txt' text file:

192.168.0.1 23
WAIT "#"
SEND "cd /proc/sys/net/ipv4/netfilter\m"
WAIT "#"
SEND "echo 8192 > ip_conntrack_max\m"
WAIT "#"
SEND "echo 600 > ip_conntrack_generic_timeout\m"
WAIT "#"
SEND "echo 10 > ip_conntrack_tcp_timeout_close\m"
WAIT "#"
SEND "echo 120 > ip_conntrack_tcp_timeout_close_wait\m"
WAIT "#"
SEND "echo 1200 > ip_conntrack_tcp_timeout_established\m"
WAIT "#"
SEND "echo 120 > ip_conntrack_tcp_timeout_fin_wait\m"
WAIT "#"
SEND "echo 60 > ip_conntrack_tcp_timeout_time_wait\m"
WAIT "#"
SEND "echo 30 > ip_conntrack_udp_timeout\m"
WAIT "#"
SEND "cd /proc/sys/net/ipv4\m"
WAIT "#"
SEND "echo 1200 > tcp_keepalive_time\m"
WAIT "#"
SEND "echo 3 > tcp_keepalive_probes\m"
WAIT "#"
SEND "cd /\m"
WAIT "#"
SEND "exit\m"

Save the 'p2ptweak.txt' file.

Next, on your desktop, right-click and make a shortcut to the telnet script tool, the TS10.exe file you extracted.

Good. Now you can run TS10 from the desktop. Go ahead and rename the desktop icon to e.g. 'Optimize

Router

' so you know what it is. OK right-click on it and select 'Properties'. In the 'Target' field the

end

of the line should look similar to this:

\TST10.exe" /r:p2ptweak.txt

Make sure it is written like this or else it might not work.

OK now you are probably wondering why it didn't work, e.g. when you run the icon, the TS10 window remains black and then disappears. This is because you need to enable telnet on your Netgear

router

. I'm afraid this is the only way to enable telnet access on the

router

so here's how (no worries, it's a doddle!).

NOTE: This is for Netgear DG834G/GT routers. Click this link

http://192.168.0.1/setup.cgi?todo=debug

and save the page to your desktop. It should be a html file that you saved to the desktop. Good. Just rename that html file to 'Enable Telnet on

Router

'.

That's it! DONE!

Now whenever you need to optimize your

router

, just double-click the 'Enable Telnet on

Router

' icon (sometimes you may be prompted for username/password, in that case, type 'admin' and 'password') followed by the 'Optimize

Router

' icon. The TS10 window should briefly appear with the script being applied. It will happen fast but don't worry, the tweak gets applied.

To confirm if the tweak got applied, telnet to the

router

and type the following line:

cd /proc/sys/net/ipv4/netfilter/

cat ip_conntrack_max

It should say '8192'. You can check and confirm the other lines by similar method.

I hope this helps you guys out as it has helped me.

Original credit goes to samPT (for the values), rperkin (for the script idea) and Albert Yale (for TS10).

NOTE: This tweak does not damage the router - at least to my knowledge. Since the tweaked settings are not permanently saved, you have nothing to worry about as the router reverts back to its original factory/firmware settings, once you reboot it.

From Wikipedia, the free encyclopedia

A reverse proxy or surrogate is a proxy server that is installed within the neighborhood of one or more servers. Typically, reverse proxies are used in front of Web servers. All connections coming from the Internet addressed to one of the Web servers are routed through the proxy server, which may either deal with the request itself or pass the request wholly or partially to the main web servers.

A reverse proxy dispatches in-bound network traffic to a set of servers, presenting a single interface to the caller. For example, a reverse proxy could be used for load balancing a cluster of web servers. In contrast, a forward proxy acts as a proxy for out-bound traffic. For example, an ISP may use a proxy to forward HTTP traffic from its clients to external web servers on the internet; it may also cache the results to improve performance.

There are several reasons for installing reverse proxy servers:

• Security: the proxy server may provide an additional layer of defense by separating or masquerading the type of server that is behind the reverse proxy. This configuration may protect the servers further up the chain - mainly through obfuscation.
• Encryption / SSL acceleration: when secure websites are created, the SSL encryption is sometimes not done by the Web server itself, but by a reverse proxy that is equipped with SSL acceleration hardware.
• Load distribution: the reverse proxy can distribute the load to several servers, each server serving its own application area. In the case of reverse proxying in the neighborhood of Web servers, the reverse proxy may have to rewrite the URLs in each webpage (translation from externally known URLs to the internal locations).
• Caching static content: A reverse proxy can offload the Web servers by caching static content, such as images. Proxy caches of this sort can often satisfy a considerable amount of website requests, greatly reducing the load on the central web server. Sometimes referred to as a Web accelerator.
• Compression: the proxy server can optimize and compress the content to speed up the load time.
• Spoon feeding: a dynamically generated page can be produced all at once and served to the reverse-proxy, which can then return it to the client a little bit at a time. The program that generates the page is not forced to remain open and tying up server resources during the possibly extended time the client requires to complete the transfer.

Ethernet crossover cable

From Wikipedia, the free encyclopedia

Crossover cable suitable for use with 100BASE-T4 Fast Ethernet

8P8C modular crossover adapter

An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly where they would normally be connected via a network switch, hub or router. For example, one would use a crossover cable to directly connect two personal computers via their network adapters.

Overview

The 10BASE-T and 100BASE-TX Ethernet standards use one wire pair for transmission in each direction. The Tx+ line from each device connects to the tip conductor and the Tx- line is connected to the ring. This requires that the transmit pair of each device be connected to the receive pair of the device on the other end. When a terminal device is connected to a switch or hub, this crossover is done internally in the switch or hub. A standard straight through cable is used for this purpose where each pin of the connector on one end is connected to the corresponding pin on the other connector.

One terminal device may be connected directly to another without the use of a switch or hub, but in that case the crossover must be done externally in the cable. Since 10BASE-T and 100BASE-TX use pairs 2 and 3, these two pairs must be swapped in the cable. This is a crossover cable. A crossover cable must also be used to connect two internally crossed devices (e.g., two hubs) as the internal crossovers cancel each other out. This can also be accomplished by using a straight through cable in series with a modular crossover adapter.

Because the only difference between the TIA/EIA-568-A and T568B pin/pair assignments are that pairs 2 and 3 are swapped, a crossover cable may be envisioned as a cable with one connector following T568A and the other T568B. Such a cable will work for 10BASE-T or 100BASE-TX. 1000BASE-T4 (Gigabit crossover) which uses all four pairs requires the other two pairs (1 and 4) to be swapped and also requires the solid/striped within each of those two pairs to be swapped.

 Crossover cable pinouts

Two pairs crossed, two pairs uncrossed

10baseT/100baseTX crossover ( shown as T568A )
Pin	Connection 1 pair	Connection 2 pair	Connection 1	Connection 2	Pins on plug face (jack is reversed)
1	3	2	white/green stripe	white/orange stripe
2	3	2	green solid	orange solid
3	2	3	white/orange stripe	white/green stripe
4	1	1	blue solid	blue solid
5	1	1	white/blue stripe	white/blue stripe
6	2	3	orange solid	green solid
7	4	4	white/brown stripe	white/brown stripe
8	4	4	brown solid	brown solid

Certain equipment or installations, including those in which phone and/or power are mixed with data in the same cable, may require that the "non-data" pairs 1 and 4 (pins 4, 5, 7 and 8) remain un-crossed.

Gigabit crossover All four pairs crossed 10base-T/100base-TX/1000base-TX/T4 crossover (shown as T568B)
Pin	Connection 1 pair	Connection 2 pair	Connection 1	Connection 2	Pins on plug face (jack is reversed)
1	2	3	white/orange stripe	white/green stripe
2	2	3	orange solid	green solid
3	3	2	white/green stripe	white/orange stripe
4	1	4	blue solid	white/brown stripe
5	1	4	white/blue stripe	brown solid
6	3	2	green solid	orange solid
7	4	1	white/brown stripe	blue solid
8	4	1	brown solid	white/blue stripe

In practice, it does not matter if your Ethernet cables are wired as T568A or T568B, just so long as both ends follow the same wiring format. It is just as valid to make a four-pair crossover using T568A, or a two pair crossover using T568B, as it is to wire them the way shown here. Typical commercially available "pre-wired" cables can follow either format depending on who made them. What this means is that you may discover that one manufacturer's cables are wired one way and another's the other way, yet both are "correct" and will work. In either case, T568A or T568B, a normal (un-crossed) cable will have both ends wired according to the layout in the first connections column.

 Other networking technologies

Other technologies use different pairs to transmit data, so crossover cables for them have different configurations to swap the transmit and receive pairs:

• Twisted pair Token ring uses T568B pairs 1 and 3 (the same as T568A pairs 1 and 2), so a crossover cable to connect two Token Ring interfaces must swap these pairs, connecting pins 4, 5, 3, and 6 to 3, 6, 4, and 5 respectively.
• A T1 cable uses T568B pairs 1 and 2, so to connect two T1 CSU/DSU devices back-to-back requires a crossover cable that swaps these pairs. Specifically, pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2 respectively.
• A 56K DDS cable uses T568B pairs 02 and 04, so a crossover cable for these devices swaps those pairs (pins 01, 02, 07, and 08 are connected to 07, 08, 01, and 02 respectively).

Automatic crossover

Automatic MDI/MDI-X Configuration is specified as an optional feature in the 1000BASE-T standard^[1], meaning that straight-through cables will usually work between Gigabit capable interfaces. This feature eliminates the need for crossover cables, obsoletes the uplink/normal ports and manual selector switches found on many older hubs and switches, greatly reducing installation errors. Note that although Automatic MDI/MDI-X is generally implemented, a crossover cable would still be required in the occasional situation that neither of the connected devices has the feature implemented and enabled.

Even for legacy 10/100 devices, many NICs, switches and hubs automatically apply an internal crossover when necessary. Besides the eventually agreed upon Automatic MDI/MDI-X, this feature may also be referred to by various vendor-specific terms including: Auto uplink and trade, Universal Cable Recognition and Auto Sensing.

Networks created using crossover cables

A two-computer network, sometimes called a peer-to-peer network, can be created using a crossover Ethernet cable. As in any other TCP/IP network, each computer needs to be assigned a unique IP address. In this network configuration, a default gateway is not used and can be unspecified.

Information on how to deploy such network can be found here

See also

• Registered jack which expands on the introduction and evolution of these connectors.

References