Connection Problems

[Realist]

~ Crackling noise on the telephone line.
Crackling noises/static on the line when using the telephone is indicative of incorrectly fitted filters.
Make sure that you have installed all your filters correctly (see here). It is important that each telephone device has a filter fitted. Don't forget fax machines and sky boxes also need a filter.

~ adsl drops out when phone call is made or received.
Incorrectly installed filters - check filters are installed correctly see here.
Faulty filters - replace one by one to identify which filter is faulty.
Fault on the line - unlikely but possible if all else has been eliminated.

~ Slow Speeds.
Various factors can cause slow download speeds.
Check out this page here for more information and fault finding tips if you have slow speeds.

~ No sync.
If your modem/router cant synchronise with the exchange (as indicated by a flashing green "adsl" light).
- adsl not active
- Problem with the local line
- Incorrectly installed filters.

~ Dropped connections.
Could be a few things:-
- ISP Problems - Check your ISP Service status records - are they doing any "load balancing".
- USB Modem - USB Modem problems are not uncommon, particularly with older PC's and unpowered usb hubs - see below.
- Maximum IP Sessions - Most routers have a limit on the number of IP sessions it can maintain. If this limit is reached then some "older" connection sessions may be dropped. Check the maxIP session limit on your router and adjust if necessary. - Instructions for the SAR110 and Voyager 205 here.

~ Frequent Dropped Connections / Loss of sync.
Not so very long ago this was a fairly rare event. However many users have recently been upgraded to 2Mb speeds and soon after found that their connections routinely drop, particularly in the evenings. This problem is now so common place that I have dedicated a page to this particular problem which is caused by low SNR here.

~ USB Modem Problems.
USB Modems can cause a lot of connection problems for some users, particularly those with older PCs.
The first thing to check would be ensure that you have the latest drivers for your usb modem which you can download from the manufacturers site. Its very important to make sure you install the drivers before connecting the modem up to your PC.
Some motherboards* and older Operating Systems** simply do not bode well with USB modems at all, and the solution in cases such as these would be to consider connecting via ethernet or a PCI adsl modem.
One of the most common issues is that the usb modem simply draws too much power from your PC. In cases such as this you should either consider buying a powered usb hub or connecting via ethernet.
USB modems can drain a lot of power from your PC, for this reason alone I much prefer a router which has its own power supply, processor and memory. The router takes over total control of your internet connection allowing your PC to get on with what you want it to do.
Most modems require 500mA of power and most modern PCs can supply a full 500mA on each USB port.
However it's worth noting that this isn't always the case, particularly on some older or cheaper PCs*. On such PCs the power available for all USB ports is limited to just 500mA in total, which can present problems if you have more than one USB device connected.
For example, you may find that your modem works until you plug a scanner in, which causes the modem to drop out, simply because there may not be sufficient power to drive both devices at the same time. This can be solved by purchasing a powered USB hub, which uses mains power rather than drawing it from the PC.
* Motherboards using Intel chipsets are usually fine. Please note that an Intel chipset is NOT the same as an Intel processor.
** Windows 95, NT and Windows 98 (first edition).
Its also worth noting that whilst the available USB bandwidth that peripherals use is limited, a USB modem will try and adapt to make use of the bandwidth that is available. Therefore if you are going to attach other USB devices such as a usb mouse or keyboard, ensure that these are plugged into the PC before hooking up the modem.
Otherwise the modem will consume a fixed bandwidth and the remaining bandwidth may not be sufficient for other USB devices. In cases such as this you will see an error messages stating that the the USB controller bandwidth is exceeded.


ADDED: This tutorial was originally posted at:
::. Kitz - adsl line and connection problems .::

[RoRo]

Originally Posted by Realist

~ Crackling noise on the telephone line.
Crackling noises/static on the line when using the telephone is indicative of incorrectly fitted filters.

Another fault for this problem can be the phone line extension lead from your modem to the ADSL Filter, where the phone extension has shorted due to heavy items on top of the cable or caught in a door hinge etc...
I had this problem and checked the cable (cheapest fix first) and found it to be a shorted wire which was exposed due to the door opening and closing.
It won't happen again, as I have routed the cable under the floorboards.