Saturday, 25 April 2009

WiFi and InSSIDer



One of the most common complaints about the BT HomeHub 2.0 is the flakiness of the wifi. Some people find it works perfectly and I have been lucky enough never to have had too many problems with it, but a lot of people complain either that their wifi connections can be intermittent, or that some PCs can connect with no trouble and other machines refuse to work.

There are usually a couple of reasons for this. Firstly, many people make use of the BT software that comes with the hub. Not only does this give you a BT adapted version of Internet Explorer that you really don't need, the software also attempts to manage your wifi adapter using the BT Wireless Manager. The first recommendation is always to get rid of the BT software - for many it has caused more trouble than it is worth. Jarviser provides some good instructions for getting rid of the software here.

The second thing you should do is change your wifi channel. The default setting of the BT HomeHub seems to be an "Automatic" setting, but this can also cause some odd things to happen, so it is best to set a manual channel. Again, Jarviser provides clear instructions for doing this here.





Which channel should you select? Well, in an ideal world, you would experiment with all of them until you found one that gave you the best possible wifi signal in all the rooms you might want to use wifi. However, in areas where there might be a lot of wifi networks, you might want to find a channel that isn't being used by one of your neighbours. That is where InSSIDer comes in. It's a neat free programme that can be used to identify all the wifi networks in the vicinity and provides a graphical output which indicates the channel that a network is using and the signal strength and signal stability.

The top trace is typical of one you might see in a busy urban environment. Lots of wifi networks in range, using several channels. The trick here is going to be to find a gap that has few users with a low signal strength. The lower trace is my own, in a rural environment with only one network visible, even though I know there are at least 4 others within 50 metres. Whether you will see these other networks depends on a range of local factors including topography, the thickness of the walls of your own and neighbours houses and the power of the access points (AP).

Have fun with InSSIDer. You might find it a very useful program indeed. Please note that it will only work on a wifi enabled PC. It won't work from a PC connected to a router by ethernet. You may have to select the correct adapter from the drop down menu on the start page.

Thursday, 23 April 2009

RouterStats Just Gets Better


I wrote about RouterStats a couple of posts ago, but over the last few weeks it has got even better with many more functions designed for the Netgear DG series routers mentioned in the last post.

It's tempting to say that if you have internet problems and a bit of spare cash, it would be worth picking up one of these classic routers, just to be able to run RouterStats with its full functionality. There are some real bargains to be had at the moment and you should be able to pick one up for under £50.

The latest release version, RouterStats 5.0d, now allows you to produce a graph of the router bitloading, the signal to noise ratio in each of the frequency "bins" and the signal attenuation - as shown in the screen shot at the top of the page and the blow-up of the actual trace at the bottom. These are all useful bits of information to have when you are hit with a line fault. Click on either to see the detail.

There are also a raft of other forms of data that you can capture and present graphically: Rx and Tx (receive and transmit!) Sync speed and noise margin, Rx and Tx SF/RS errors, and Rx CRC errors, errored seconds and losses of framing.

Saturday, 18 April 2009

Alternative Routers For Poor Connections


Many BT customers have found that the BT HomeHub is not, perhaps, the most useful router in the world. HomeHub 2.0, despite the advertising claims, is not very good at holding onto synch on very long or poor telephone lines. Furthermore, it is even less useful than the earlier versions, as BT have got the firmware locked down so tightly that it has proved impossible to use it to gather continuous information of the sort gathered by RouterStats and RouterStats Lite. This is important if you are suffering from a connection problem or slow speeds. Often this is exactly the sort of information you need to gather, in order to convince BT you have a problem.

What are the alternatives? Well, any router can be used to connect to BT Broadband and setting them up is relatively straightforward - but doing so will mean that you can't use BT features such as the web phones. One of the questions often asked on web forums is which router is the best replacement for the HomeHub? Unfortunately the answer is far from straightforward and it amounts to "whichever works best in your particular set of circumstances".

My own experience, at the end of a very poor quality and noisy line, has shown that if all you want to do is maintain synch as best you can and record basic information to present to BT, then BT's Business Hub, the 2-Wire 2700HGV is one of the best and most stable routers around. If you are having real problems with a BT Broadband connection and have managed to get through to BT's third-line support, they may even offer you one to try - if not, they can be picked up off e-Bay.

More recently, and following email exchanges with BT Broadband guru Jarviser, I've gone back to using an old Netgear DG834PN router. Netgear routers have long had the reputation for being excellent devices that can hold on to synch like glue. They are also the routers that RouterStats was originally designed to work with and so you can make use of all the features of that software too.

Best of all, the Netgear DG series of routers:

Netgear DG834(G) Versions 1.0, 2.0, 3.0 or 4.0
Netgear DG834GT
Netgear DG834PN
Netgear DG834N version 1
Netgear DG834 2000

have firmware that can be tweaked. Now the best Netgear tweakers are a bunch of crazy Italians called the DGTeam, whose somewhat irreverent logo appears at the head of this post. They describe their mission as follows:

This project was born with the purpose of making experiments on Netgear DG834XX Adsl Router Series, first of all fixing many little issues we found out on official releases and after this, trying to improve its performances adding new features.

Why is the DGTeam firmware so useful? Well, it allows you to go on the offensive when it comes to trying to improve your connection - and to do it without having to dig into the guts of the firmware. The most important feature is the ability to tweak the signal to noise (S/N) margin target for your connection. OK, you might not understand what this is, or how it affects your connection, but what it does is as follows.

The lower the S/N target, the higher the sync speed your connection can achieve, but the more unstable your connection might become. The converse is also true, with higher S/N margins leading to lower synch speeds, but more stable connections. When you first get BT Broadband, the default S/N target is 6 decibels (6dB - but don't worry about the units - it's what they do that matters). If you have a poor connection, equipment at your local exchange called the DSLAM will cause your synch speed and IP profile (which fixes the maximum download speed) to drop, and the S/N target may rise. It goes up in 3dB steps - so 6, 9, 12 and 15 dB and will keep going up until your connection seems stable. However, at this point, your IP profile may have dropped as low as 135kbps and you might have an S/N target of 15+ - a very stable sub dial-up speed broadband connection. About as much use as a chocolate teapot.

Now the BT S/N settings might best be described as "conservative" as they err on the side of caution when it comes to giving a stable connection/speed combination.

This is where the DGTeam firmware comes in. It allows you to easily adjust the S/N target yourself, which can often improve either your speed or stability - the choice is yours. The S/N setting in the firmware is normally set to 100% - the value BT want you to connect at. Increasing it to 120% will make your connection much more stable, but slower. Decreasing it to, say, 80% will make your synch speed faster, but your connection may become a little more unstable. If you can lower the S/N margin enough, without your router losing synch, you may be able to encourage the DSLAM to increase your IP profile and thus the download speed of your connection.

Now, it normally takes a very long time for the BT DSLAM to lower the S/N margin, if your connection improves of its own accord (eg because of better weather), so using the DGTeam firmware can be a big help!

Finally, the DGTeam firmware is compatible with RouterStats.

WARNING: If you are going to try the DGTeam firmware, you MUST flash it to your router using a Windows XP machine. Using Vista may result in a very dead router!
If you are too enthusiastic about lowering the S/N target, you may make your router so unstable that the IP profile drops even further, leaving you with a slower connection than you had before. Of course, if you already have a connection running at sub dial-up speeds, you don't really have much to lose.

Friday, 10 April 2009

Things That Can Affect Your Broadband Speed

There are several things that can affect the speed (bandwidth) and quality of your broadband connection. Some of them you can do something about. For others, about the only thing you can do is to move house, or wait in the hope that BT or another infrastructure provider will improve the network.

The key factors are:

* The length, and quality, of line between your house and the exchange. Although many last mile and middle mile cables are copper, some of those installed in the 1960s and 1970s are aluminium which suffers much more attenuation than copper and results in slower speeds per unit distance from the exchange. If the cable has been repaired many times, or has lots of joints, or has different sections of cable of different thickness, or material, this can all increase attenuation and reduce speeds. Cables and drop wires (the last bits of wire from the telegraph pole to your house) can get damaged by trees rubbing against them, or just general degradation with time.

* The weather. Wet weather in particular can reduce connection speeds. Damp gets into cable joints and increases attenuation. Thunder storms can introduce radio frequency (RF) noise into the telephone lines and this can be enough to cause your router to lose sync with the exchange. Always turn of your computer and router at the first sign of a thunderstorm - and keep them off until the storm has passed. If you can hear crackling on a radio, it is still too soon to restart your broadband network - a distant storm may not be enough to damage your equipment, but it could cause enough resyncs in a short space of time to get your IP profile reduced and so your speed will be reduced

* The quality of wiring, electrical equipment and phone extension wiring inside your house. The most likely cause of RF interference to your broadband lie within the house. Poor switches, pumps, motors, Sky Satellite boxes, etc, etc., can all mess up your connection. Try running your broadband from the BT test socket - if this improves things, you need to start by checking your BT socket to see if the orange bell-wire is still connected (if it is, go to Jarviser's site on the left of this page for tips on how to remove it). If this doesn't improve things, turn off all the electrical devices in the house, then turn them back on, one at a time, until the faulty device is found.

* The quality of wiring, electrical equipment and phone extension wiring inside your neighbours houses. Once you have eliminated all your own sources of interference, you may have to go and talk to the neighbours. If they have broadband, they may have noticed a similar problem and be prepared to help find the source.

* The time of day; peak times, especially once the kids get home from school, can result in slower speeds, especially if your provider has a lot of users locally. There isn't much you can do about this, other than complain to your ISP if things get too bad.

* The speed of your PC or laptop; a slow running machine can affect performance. Download and run a free application called CCleaner to remove all the clutter you can from your PC. Run your virus and spyware checker (You have these - don't you!). Defragment your hard drive. These may be sufficient to give you a small increase in speed. Failing that, try adding some RAM. Of course, you may decide a new PC is what is needed. It all depends how badly you want or need more speed.

* Traffic 'shaping', or management; when a provider like BT slows your connection because it prefers one kind of traffic over another (for example, BT Vision over Peer-to-Peer file sharing, downloading, etc). About the only thing you can do is to try and find another ISP that does no traffic shaping or less traffic shaping.

Sunday, 5 April 2009

RouterStats and RouterStats Lite

When you get broadband problems, it's always as well to try and collect as much information as you can about what is going on. To my mind, two of the best programs for collecting the sort of data you may need to present to your ISP, to convince them there is a problem, are RouterStats and RouterStats Lite. These were written by a bright chap called John Owen.

These programmes are designed to continuously capture data from your HomeHub (Version 1.0 and 1.5 - but sadly, not the latest Version 2.) or other router and present it, and save it, in graphical form. The two key bits of data it collects are the speed your router wishes to connect to the exchange at and the signal to noise margin. The output looks like this:



This trace is fairly typical of a nasty problem known as Repetitive Electrical Impulse Noise (REIN). At the start of the trace, the signal to noise margin is around 12dB. When the REIN hits, there is a sudden spike of interference on the phone line and the router synchronisation with the exchange is lost. When the router recovers, the signal to noise margin has increased and the speed has dropped through the floor. If you are really unlucky and this happens too often, the BT equipment at the exchange will cut your IP profile in an attempt to stabilize the line - which can result in your speed dropping and dropping until it reaches sub-dial-up speeds.

If your line doesn't see any problems for a while, the speed can climb again, but it will take days (at least) to reach its previous levels.

It's very hard to collect this sort of data without RouterStats/RouterStats Lite, which is why I recommend it.

Oh, and did I mention, these wonderful programmes are FREE, courtesy of John Owen - another unsung hero of British broadband!
Having had some major problems with my own broadband service, I understand how others struggle to get help from BT.

There is a lot of good information out there, but it can be hard to find. So this blog is an attempt to pull some of it together, in one place.

It's a blog that really shouldn't be needed - if only BT and possibly other ISP's in the UK, provided useful customer support.