Introduction

This guide shows how to speed up downloads in the freeware bittorrent client,  Transmission-QT (Windows). All bittorrent programs need to have their incoming and outgoing communications flow freely in order to achieve the highest download speeds and that is what this guide is about.

This guide was put together using information given by the developers of bittorrent programs at their forums, guides and FAQs. There are no secret tricks, just the real basics of proper set up of a bittorrent program. Following these simple steps should result in increased download speed.

 

These are the basic principles of optimizing a bittorrent client, like Transmission-QT (Windows), for speed: 

• Choose a proper port to avoid ISP blocks and conflicts with other programs
• Forward that port through any software firewall and router to allow incoming connections
• Adjust internal settings based upon upload capacity of the internet connection to allow room for outgoing communications and to distribute upload efficiently. 

There are some programs that claim to optimize speed in Transmission-QT (Windows).Such programs are a scam and generally contain adware or spyware. I have seen it said, by the developers of all bittorrent programs, that nothing will increase your download speed in a bittorrent client more than the basic steps set forth herein.

If you are not using Transmission-QT (Windows), there are several other specific guides for other clients and a general guide here:
Optimizing Bittorrent Clients

This guide is based upon Version 2.41 of Transmission-QT (Windows).

Accessing Settings

Select Edit>Preferences from the menus on the upper left.

Choosing A Proper Port

To avoid messing up a network connection that is already cleared, first check and see if your communications are blocked or are already clear. 

Select Edit>Preferences>Network in the Transmission-QT (Windows) program and press the "Test Port" button:

Make sure that the Pick a random port each time Transmission is started option should be disabled as this could affect router and firewall settings and rarely serves any useful purpose.

If your port shows open, skip the next part of this guide and proceeed to Adjusting Internal Settings section of this guide.

If you failed the port test above, then you should first set your port to a proper one.  The most important choice here is to avoid using a port within the 6881-6999 range. This was the range originally used by bittorrent programs and is often blocked by Internet Service Providers (ISPs). (If your port was in this range, change and re-test).

The safest choice is a port in the 49160-65534 range as this will avoid ISP blocks and possible conflicts with other applications.  This range used to be 49152-65534, but apparently Vista and Windows 7 grabs some of those ports in between.   Vuze-Wiki: Port is Blacklisted

Windows users, if you want to make certain there is no conflict.  Go to the command prompt and type in netstat -a >c:\log.txt  This will check to see which ports are being used and save a log text file at C:\.  Looking at the text file, you will know which ports to avoid.

To change the port, simply enter a new port number in the  box indicated in the image above. 

If your port did not show Open, then proceed through the following steps.

Introduction
A router will block incoming communications unless an exception is made. All software firewalls will block incoming communications and most will also block outgoing communications, unless an exception is made. If you are "firewalled", then other people will not be able to initiate connections with you (see Why Is Being Firewalled Bad).
As there are many firewalls and routers, this guide can not give explanations as to each. However, there are guides available, on the internet for most firewalls and routers and this guide will link you to them.  Note that PortForward.com does not have guides specific to Transmission-QT (Windows).  Choose a µTorrent guide and substitute Transmission-QT (Windows) where µTorrent is indicated.

Software Firewall - The permission should be set to allow TCP and UDP in both directions. Generally, you will have a choice to set permission for the Transmission-QT (Windows) port or for the Transmission-QT (Windows) program. Setting permission for the port is the safer choice. You can check these options for guides:

• The help file of your software firewall is the best place to look
•  The µTorrent forum  has some guides posted
•  PortForward.com Firewall Guides(choose firewall and then µTorrent) also has some guides.

Router - There are two choices here.  The easier way is to use UPnP.  However, this has a possible security issue.  Using UPnP allows any program to create a port mapping through the router without consent of the owner.  Note:  Given the recent findings of Rapid7 regarding security flaws in UPnP, it is generally suggested here that manual forwarding be used.  If you still want to use UPnP, then it would be a good idea to test and see if your device is vulnerable to attack through UPnP.

The other choice is to manually forward the port through the router.  This does not have that security issue, but involves going through several steps to accomplish.  Using the guides linked herein, this should not be that difficult and is the preferred method.

UPnP - The Easy Way -  Enable UPnP in Transmission-QT (Windows) and router.

In Transmission-QT (Windows) the setting for UPnP is at Edit>Preferences>Network.  Simply enter a mark in the box next to this option.

Manual Forwarding-The Preferred Way

1. UPnP (NAT-PMP) Must be disabled in Transmission-QT (Windows) (see image above)
2. Use the Static IP Guide
3. Set permission for Transmission-QT (Windows) port. This should be set to allow both TCP and UDP communications.
   You can check these options for guides:

• The help file of your router is the best place to look
• Portforward.com µTorrent Router Index has guides for most routers 

Re-Test the port.  If the port shows open, then proceed on to thhe next section of this guide.  If the port still does not show open, re-do steps or seek help in Forums.

Adjusting Internal Settings

Introduction
The most important setting here is to cap upload in Transmission-QT (Windows) to 80% of your overall upload capacity. Setting upload in Transmission-QT (Windows) is a fine line. The more upload you give, the more download you will get from other peers. However, if upload is set too high, or to unlimited, then download speeds will suffer as outgoing communications (acknowledgment signals, resend requests etc) will be interfered with. Other adjustments are made here to distribute your upload so that you receive back the most download from other peers.

Speed Test: Speedtest.net (Click for Test)
First the upload capacity of your internet connection must be determined by taking an online speed test. Speedtest.net has test locations worldwide and will highlight the one closest to you.
To take the test you must have Flash installed and javascript enabled. 

Before taking the speed test, press Settings in the upper right of the speedtest.net page.  This will take you to another page.  At the bottom of that page is the "Global Settings" options.  Set "Speed Measurement" to kilobytes and press "Save" .  This will facilitate entry into the calculator below and will lessen confusion as qBittorrent shows speeds in kilobytes.

 

 

You should stop all internet activity, including torrents, before taking the test and the test should be taken a few times to obtain a reliable average. Results will now show in KiloBytes. It is the upload rate that is important here.

Another Way To Test Upload Speed

For most people these test results will be reliable (Comcast users see Note). However, you may wish to do a double check on real life upload speed. When you are active on a torrent with a good number of peers and you are using your upload cap, set upload to unlimited and watch for about 5-10 minutes and see where upload settles in at. Then input that number into the calculator in the kiloBytes section. 

Note: Some ISPs will show inaccurate results on the speed test. If your ISP has anything like Comcast's PowerBoost, then your results will show higher than the actual speed of your connection. PowerBoost provides a burst of download and upload speeds above your provisioned download and upload speeds for the first 10MB and 5MB respectively. Since the speed test involves relatively small files, this will skew results upward.
If you have PowerBoost, or something similar, my findings from my own results and those of others is that the actual speeds are 60% of the test result.  So if you get 200kB/s for upload at the test, you should enter 120 in the kB/s box in the calculator.  Using Google ("speed result" x .6) will get the proper number to enter in  the calculator and this actually turns out to be very accurate.  You should end up with the calculator showing a cap that is about half of the test result.

Calculator:  Azureus Upload Settings Calculator

Once you have an average upload speed for your connection go to the online Azureus Upload Settings Calculator. Although designed for Azureus, this calculator will work for all bittorrent clients.
This calculator was created by the8472 a contributor to Vuze (fka Azureus) and part of the team that created Bittorrent Protocol Encryption.

Enter your average upload speed in the appropriate box

The calculator will automatically give the proper figures to adjust bandwidth, connections and queue  options in Transmission-QT (Windows).

Speed - Edit>Preferences>Speed enable option to limit Upload and set number from calculator.  Do not limit download.

There are Temporary Speed Limit Settings options below.  These should not be enabled at this time.  These settings are to limit bandwidth use at certain times of day.  Particularly useful if your ISP charges for bandwidth at certain times and not other times.

Connections: The setting is located at Edit>Preferences>Network

Queue:  The settings for Queue options are at Edit>Preferences>Download

There is only a setting for Maximum active downloads. The appropriate number from the calculator should be entered there.
The setting below that should not be changed.

Peer Sources & Encryption & µTP

Having the proper peer sources enabled, such as Peer Exchange (PEX) and Distributed Hash Table (DHT), will help download speeds as they will help you find additional seeds and peers for a torrent. 
Encryption was primarily designed to thwart Internet Service Providers interference with bittorrent.  Having encryption enabled and allowing incoming legacy (non-encrypted) connections will provide you with the largest pool of seeds/peers to select from.
µTP is a protocol developed by µTorrent to send communications through UDP.  Without going into more detail, this will allow you to connect to more peers as many users utilize this mode.

The settings for PEX, DHT and Encryption are at Edit>Preferences>Privacy and should be set as in image below

The setting to enable µTP for peer connections is at Edit>Preferences>Network

 

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Gizmo's Best Ever Freeware Forums

If you still have issues after using this guide and would like some assistance, you may post here or our Forums.  The comments section here is not well set up for ongoing discussions, so the forums are a better place.

When posting on a speed issue, please provide

• Your speed test result for both upload and download speed in kiloBytes per second (kBps)
• Your result at canyouseeme, both before taking any steps and after.  Just indicate Success or Error do not post your IP address.

If you have a suggestion or correction for the guide, please post here.

Those who wish to post a thanks may post here or in the forums. I always appreciate hearing from those who this helped and I do read the posts regularly. I used to respond to each thanks, but realized it was clogging up the comments section. I thank all those who have posted their appreciation and all those who will.

So, to those who post a "Thanks", I appreciate it.